|
Fair Values of U.S. Pension and Postretirement Benefit Plan Assets by Asset Category as Well as the Percentage That Each Category Comprises of Total Plan Assets and the Respective Target Allocations (Detail) (USD $)
In Millions, unless otherwise specified |
12 Months Ended | 12 Months Ended | 12 Months Ended | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
|
Dec. 31, 2011
|
Dec. 31, 2010
|
Dec. 31, 2011
Cash and Cash Equivalents
|
Dec. 31, 2010
Cash and Cash Equivalents
|
Dec. 31, 2011
Equity Securities
|
Dec. 31, 2010
Equity Securities
|
Dec. 31, 2011
Equity Securities
US Large Cap
|
Dec. 31, 2010
Equity Securities
US Large Cap
|
Dec. 31, 2011
Equity Securities
US Small Cap
|
Dec. 31, 2010
Equity Securities
US Small Cap
|
Dec. 31, 2011
Equity Securities
International Core
|
Dec. 31, 2010
Equity Securities
International Core
|
Dec. 31, 2011
Equity Securities
Emerging Markets
|
Dec. 31, 2010
Equity Securities
Emerging Markets
|
Dec. 31, 2011
Equity Securities
International Small Cap
|
Dec. 31, 2010
Equity Securities
International Small Cap
|
Dec. 31, 2011
Equity Securities
Global Equity
|
Dec. 31, 2011
Fixed Income Securities
|
Dec. 31, 2010
Fixed Income Securities
|
Dec. 31, 2011
Fixed Income Securities
U.S. Government Securities
|
Dec. 31, 2010
Fixed Income Securities
U.S. Government Securities
|
Dec. 31, 2011
Fixed Income Securities
Corporate Bonds
|
Dec. 31, 2010
Fixed Income Securities
Corporate Bonds
|
Dec. 31, 2011
Fixed Income Securities
U.S. state and local municipal debt securities
|
Dec. 31, 2010
Fixed Income Securities
Mortgage-Backed Securities
|
Dec. 31, 2011
Other Investments
Hedge Funds
|
Dec. 31, 2010
Other Investments
Hedge Funds
|
Dec. 31, 2011
Other Investments
Real Estate
|
Dec. 31, 2010
Other Investments
Real Estate
|
Dec. 31, 2011
Other Investments
Private Equity
|
Dec. 31, 2010
Other Investments
Private Equity
|
Dec. 31, 2011
Fair Value, Inputs, Level 1
|
Dec. 31, 2010
Fair Value, Inputs, Level 1
|
Dec. 31, 2011
Fair Value, Inputs, Level 1
Cash and Cash Equivalents
|
Dec. 31, 2011
Fair Value, Inputs, Level 1
Equity Securities
|
Dec. 31, 2010
Fair Value, Inputs, Level 1
Equity Securities
|
Dec. 31, 2011
Fair Value, Inputs, Level 1
Equity Securities
US Large Cap
|
Dec. 31, 2010
Fair Value, Inputs, Level 1
Equity Securities
US Large Cap
|
Dec. 31, 2011
Fair Value, Inputs, Level 1
Equity Securities
US Small Cap
|
Dec. 31, 2010
Fair Value, Inputs, Level 1
Equity Securities
US Small Cap
|
Dec. 31, 2011
Fair Value, Inputs, Level 1
Equity Securities
International Core
|
Dec. 31, 2010
Fair Value, Inputs, Level 1
Equity Securities
International Core
|
Dec. 31, 2011
Fair Value, Inputs, Level 1
Equity Securities
Emerging Markets
|
Dec. 31, 2010
Fair Value, Inputs, Level 1
Equity Securities
Emerging Markets
|
Dec. 31, 2011
Fair Value, Inputs, Level 1
Equity Securities
International Small Cap
|
Dec. 31, 2010
Fair Value, Inputs, Level 1
Equity Securities
International Small Cap
|
Dec. 31, 2011
Fair Value, Inputs, Level 1
Equity Securities
Global Equity
|
Dec. 31, 2011
Fair Value, Inputs, Level 1
Fixed Income Securities
|
Dec. 31, 2010
Fair Value, Inputs, Level 1
Fixed Income Securities
|
Dec. 31, 2011
Fair Value, Inputs, Level 1
Fixed Income Securities
U.S. Government Securities
|
Dec. 31, 2010
Fair Value, Inputs, Level 1
Fixed Income Securities
U.S. Government Securities
|
Dec. 31, 2011
Fair Value, Inputs, Level 1
Fixed Income Securities
Corporate Bonds
|
Dec. 31, 2010
Fair Value, Inputs, Level 1
Fixed Income Securities
Corporate Bonds
|
Dec. 31, 2011
Fair Value, Inputs, Level 1
Other Investments
Real Estate
|
Dec. 31, 2010
Fair Value, Inputs, Level 1
Other Investments
Real Estate
|
Dec. 31, 2011
Fair Value, Inputs, Level 2
|
Dec. 31, 2010
Fair Value, Inputs, Level 2
|
Dec. 31, 2011
Fair Value, Inputs, Level 2
Cash and Cash Equivalents
|
Dec. 31, 2010
Fair Value, Inputs, Level 2
Cash and Cash Equivalents
|
Dec. 31, 2011
Fair Value, Inputs, Level 2
Equity Securities
|
Dec. 31, 2010
Fair Value, Inputs, Level 2
Equity Securities
|
Dec. 31, 2011
Fair Value, Inputs, Level 2
Equity Securities
US Large Cap
|
Dec. 31, 2011
Fair Value, Inputs, Level 2
Equity Securities
US Small Cap
|
Dec. 31, 2011
Fair Value, Inputs, Level 2
Equity Securities
International Core
|
Dec. 31, 2010
Fair Value, Inputs, Level 2
Equity Securities
International Core
|
Dec. 31, 2011
Fair Value, Inputs, Level 2
Equity Securities
Emerging Markets
|
Dec. 31, 2010
Fair Value, Inputs, Level 2
Equity Securities
Emerging Markets
|
Dec. 31, 2011
Fair Value, Inputs, Level 2
Equity Securities
International Small Cap
|
Dec. 31, 2010
Fair Value, Inputs, Level 2
Equity Securities
International Small Cap
|
Dec. 31, 2011
Fair Value, Inputs, Level 2
Equity Securities
Global Equity
|
Dec. 31, 2011
Fair Value, Inputs, Level 2
Fixed Income Securities
|
Dec. 31, 2010
Fair Value, Inputs, Level 2
Fixed Income Securities
|
Dec. 31, 2011
Fair Value, Inputs, Level 2
Fixed Income Securities
U.S. Government Securities
|
Dec. 31, 2010
Fair Value, Inputs, Level 2
Fixed Income Securities
U.S. Government Securities
|
Dec. 31, 2011
Fair Value, Inputs, Level 2
Fixed Income Securities
Corporate Bonds
|
Dec. 31, 2010
Fair Value, Inputs, Level 2
Fixed Income Securities
Corporate Bonds
|
Dec. 31, 2011
Fair Value, Inputs, Level 2
Fixed Income Securities
U.S. state and local municipal debt securities
|
Dec. 31, 2010
Fair Value, Inputs, Level 2
Fixed Income Securities
Mortgage-Backed Securities
|
Dec. 31, 2010
Fair Value, Inputs, Level 2
Other Investments
Real Estate
|
Dec. 31, 2011
Fair Value, Inputs, Level 3
|
Dec. 31, 2010
Fair Value, Inputs, Level 3
|
Dec. 31, 2009
Fair Value, Inputs, Level 3
|
Dec. 31, 2011
Fair Value, Inputs, Level 3
Hedge Funds
|
Dec. 31, 2010
Fair Value, Inputs, Level 3
Hedge Funds
|
Dec. 31, 2009
Fair Value, Inputs, Level 3
Hedge Funds
|
Dec. 31, 2011
Fair Value, Inputs, Level 3
Real Estate
|
Dec. 31, 2010
Fair Value, Inputs, Level 3
Real Estate
|
Dec. 31, 2009
Fair Value, Inputs, Level 3
Real Estate
|
Dec. 31, 2011
Fair Value, Inputs, Level 3
Private Equity
|
Dec. 31, 2010
Fair Value, Inputs, Level 3
Private Equity
|
Dec. 31, 2009
Fair Value, Inputs, Level 3
Private Equity
|
Dec. 31, 2011
Fair Value, Inputs, Level 3
Corporate Bonds
|
Dec. 31, 2010
Fair Value, Inputs, Level 3
Corporate Bonds
|
Dec. 31, 2009
Fair Value, Inputs, Level 3
Corporate Bonds
|
Dec. 31, 2011
Fair Value, Inputs, Level 3
Fixed Income Securities
|
Dec. 31, 2010
Fair Value, Inputs, Level 3
Fixed Income Securities
|
Dec. 31, 2011
Fair Value, Inputs, Level 3
Fixed Income Securities
Corporate Bonds
|
Dec. 31, 2010
Fair Value, Inputs, Level 3
Fixed Income Securities
Corporate Bonds
|
Dec. 31, 2011
Fair Value, Inputs, Level 3
Other Investments
Hedge Funds
|
Dec. 31, 2010
Fair Value, Inputs, Level 3
Other Investments
Hedge Funds
|
Dec. 31, 2011
Fair Value, Inputs, Level 3
Other Investments
Real Estate
|
Dec. 31, 2010
Fair Value, Inputs, Level 3
Other Investments
Real Estate
|
Dec. 31, 2011
Fair Value, Inputs, Level 3
Other Investments
Private Equity
|
Dec. 31, 2010
Fair Value, Inputs, Level 3
Other Investments
Private Equity
|
|
| Defined Benefit Plan Disclosure [Line Items] | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Fair value of plan assets | $ 22,837 | $ 20,325 | $ 75 | $ 579 | $ 9,282 | $ 9,032 | $ 4,724 | $ 4,897 | $ 733 | $ 874 | $ 1,518 | $ 2,139 | $ 653 | $ 809 | $ 527 | $ 313 | $ 1,127 | $ 8,284 | $ 6,360 | $ 4,629 | $ 3,815 | $ 3,551 | $ 2,495 | $ 104 | $ 50 | $ 2,743 | $ 2,023 | $ 1,099 | $ 1,022 | $ 1,354 | $ 1,309 | $ 9,074 | $ 11,843 | $ 74 | $ 5,428 | $ 7,635 | $ 2,264 | $ 4,897 | $ 706 | $ 874 | $ 592 | $ 1,219 | $ 389 | $ 528 | $ 362 | $ 117 | $ 1,115 | $ 3,421 | $ 4,110 | $ 3,412 | $ 3,502 | $ 9 | $ 608 | $ 151 | $ 98 | $ 8,638 | $ 4,168 | $ 1 | $ 579 | $ 3,854 | $ 1,397 | $ 2,460 | $ 27 | $ 926 | $ 920 | $ 264 | $ 281 | $ 165 | $ 196 | $ 12 | $ 4,783 | $ 2,057 | $ 1,217 | $ 313 | $ 3,462 | $ 1,694 | $ 104 | $ 50 | $ 135 | $ 5,125 | $ 4,314 | $ 3,180 | $ 2,743 | $ 2,023 | $ 1,284 | $ 948 | $ 789 | $ 550 | $ 1,354 | $ 1,309 | $ 1,145 | $ 80 | $ 193 | $ 201 | $ 80 | $ 193 | $ 80 | $ 193 | $ 2,743 | $ 2,023 | $ 948 | $ 789 | $ 1,354 | $ 1,309 |
| Percentage of Plan Assets | 0.30% | 2.90% | 12.00% | 10.00% | 5.90% | 6.40% | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Percentage of Plan Assets | 40.70% | 44.40% | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Percentage of Plan Assets | 36.30% | 31.30% | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Percentage of Plan Assets | 4.80% | 5.00% | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Percentage of Plan Assets | 100.00% | 100.00% | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Plan assets target allocation, Minimum | 0.00% | 0.00% | 5.00% | 5.00% | 1.00% | 1.00% | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Plan assets target allocation, Maximum | 5.00% | 5.00% | 15.00% | 15.00% | 10.00% | 10.00% | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Plan assets target allocation, Minimum | 40.00% | 40.00% | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Plan assets target allocation, Maximum | 60.00% | 60.00% | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Plan assets target allocation, Minimum | 20.00% | 20.00% | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Plan assets target allocation, Maximum | 40.00% | 40.00% | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Plan assets target allocation, Minimum | 1.00% | 1.00% | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Plan assets target allocation, Maximum | 10.00% | 10.00% | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Plan assets target allocation | 100.00% | 100.00% | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||