Carrying Value of Outstanding Debt (Detail) (USD $) In Millions, unless otherwise specified
|
3 Months Ended |
|
Mar. 31, 2013
|
Dec. 31, 2012
|
Debt Instrument [Line Items] |
|
|
Debt Instrument, Face Amount |
$ 12,274
|
|
Long-term Debt and Capital Lease Obligations |
12,666
|
12,870
|
Less current maturities |
(1,615)
|
(1,781)
|
Long-Term Debt |
11,051
|
11,089
|
4.50% stated rate
|
|
|
Debt Instrument [Line Items] |
|
|
Debt Instrument, Face Amount |
1,750
|
|
Debt instrument, stated interest rate |
4.50%
|
|
Commercial Paper
|
|
|
Debt Instrument [Line Items] |
|
|
Debt Instrument, Face Amount |
1,572
|
|
Maturity - Minimum Date |
Dec. 31,
2013
|
|
Maturity - Maximum Date |
Dec. 31,
2013
|
|
Total debt |
1,572
|
0
|
Senior notes | 4.50% stated rate
|
|
|
Debt Instrument [Line Items] |
|
|
Debt Instrument, Face Amount |
0
|
|
Maturity - Maximum Date |
Jan. 15,
2013
|
|
Debt instrument, stated interest rate |
4.50%
|
|
Total debt |
0
|
1,751
|
Senior notes | 3.875% stated rate
|
|
|
Debt Instrument [Line Items] |
|
|
Debt Instrument, Face Amount |
1,000
|
|
Maturity - Maximum Date |
Apr. 15,
2014
|
|
Debt instrument, stated interest rate |
3.875%
|
|
Total debt |
1,027
|
1,033
|
Senior notes | 5.50% stated rate
|
|
|
Debt Instrument [Line Items] |
|
|
Debt Instrument, Face Amount |
750
|
|
Maturity - Maximum Date |
Jan. 15,
2018
|
|
Debt instrument, stated interest rate |
5.50%
|
|
Total debt |
844
|
851
|
Senior notes | 5.125% stated rate
|
|
|
Debt Instrument [Line Items] |
|
|
Debt Instrument, Face Amount |
1,000
|
|
Maturity - Maximum Date |
Apr. 15,
2019
|
|
Debt instrument, stated interest rate |
5.125%
|
|
Total debt |
1,130
|
1,140
|
Senior notes | Debentures 8 Point 375 Percent Due 2030 [Member]
|
|
|
Debt Instrument [Line Items] |
|
|
Debt Instrument, Face Amount |
276
|
|
Total debt |
284
|
284
|
Senior notes | 3.125% stated rate
|
|
|
Debt Instrument [Line Items] |
|
|
Debt Instrument, Face Amount |
1,500
|
|
Maturity - Maximum Date |
Jan. 15,
2021
|
|
Debt instrument, stated interest rate |
3.125%
|
|
Total debt |
1,645
|
1,655
|
Senior notes | 6.20% stated rate
|
|
|
Debt Instrument [Line Items] |
|
|
Debt Instrument, Face Amount |
1,500
|
|
Maturity - Maximum Date |
Jan. 15,
2038
|
|
Debt instrument, stated interest rate |
6.20%
|
|
Total debt |
1,481
|
1,480
|
Senior notes | 4.875% stated rate
|
|
|
Debt Instrument [Line Items] |
|
|
Debt Instrument, Face Amount |
500
|
|
Maturity - Maximum Date |
Nov. 15,
2040
|
|
Debt instrument, stated interest rate |
4.875%
|
|
Total debt |
489
|
489
|
Senior notes | A1125SeniorNotes [Member]
|
|
|
Debt Instrument [Line Items] |
|
|
Debt Instrument, Face Amount |
375
|
|
Maturity - Maximum Date |
Oct.
01,
2017
|
|
Debt instrument, stated interest rate |
1.125%
|
|
Total debt |
372
|
373
|
Senior notes | 2.45% senior notes [Member]
|
|
|
Debt Instrument [Line Items] |
|
|
Debt Instrument, Face Amount |
1,000
|
|
Maturity - Maximum Date |
Oct.
01,
2022
|
|
Debt instrument, stated interest rate |
2.45%
|
|
Total debt |
988
|
996
|
Senior notes | 3.625% senior notes [Member]
|
|
|
Debt Instrument [Line Items] |
|
|
Debt Instrument, Face Amount |
375
|
|
Maturity - Maximum Date |
Oct.
01,
2042
|
|
Debt instrument, stated interest rate |
3.625%
|
|
Total debt |
367
|
367
|
Senior notes | Debentures 8 Point 375 Percent Due 2020 [Member]
|
|
|
Debt Instrument [Line Items] |
|
|
Debt Instrument, Face Amount |
424
|
|
Total debt |
506
|
512
|
Senior notes | Floating rate senior notes
|
|
|
Debt Instrument [Line Items] |
|
|
Debt Instrument, Face Amount |
377
|
|
Maturity - Minimum Date |
Jan.
01,
2049
|
|
Maturity - Maximum Date |
Jan.
01,
2053
|
|
Total debt |
373
|
374
|
Debentures [Member] | 8.375% debentures due 2030 [Member]
|
|
|
Debt Instrument [Line Items] |
|
|
Maturity - Maximum Date |
Jan.
01,
2030
|
|
Debt instrument, stated interest rate |
8.375%
|
|
Debentures [Member] | 8.375% debentures due 2020 [Member]
|
|
|
Debt Instrument [Line Items] |
|
|
Maturity - Minimum Date |
Jan.
01,
2020
|
|
Debt instrument, stated interest rate |
8.375%
|
|
Facility notes and bonds
|
|
|
Debt Instrument [Line Items] |
|
|
Debt Instrument, Face Amount |
320
|
|
Maturity - Minimum Date |
Jan.
01,
2015
|
|
Maturity - Maximum Date |
Jan.
01,
2036
|
|
Total debt |
320
|
320
|
Pound Sterling notes
|
|
|
Debt Instrument [Line Items] |
|
|
Maturity - Minimum Date |
Jan.
01,
2031
|
|
Maturity - Maximum Date |
Jan.
01,
2050
|
|
Pound Sterling notes | Pound Sterling Notes 5 Point 5 Percent [Member]
|
|
|
Debt Instrument [Line Items] |
|
|
Debt Instrument, Face Amount |
101
|
|
Total debt |
96
|
103
|
Pound Sterling notes | Pound Sterling Notes 5 Point 13 Percent [Member]
|
|
|
Debt Instrument [Line Items] |
|
|
Debt Instrument, Face Amount |
688
|
|
Total debt |
656
|
699
|
Capital Lease Obligations
|
|
|
Debt Instrument [Line Items] |
|
|
Debt Instrument, Face Amount |
513
|
|
Maturity - Minimum Date |
Dec. 31,
2013
|
|
Maturity - Maximum Date |
Jan.
01,
3004
|
|
Total debt |
513
|
440
|
Other debt
|
|
|
Debt Instrument [Line Items] |
|
|
Debt Instrument, Face Amount |
3
|
|
Maturity - Maximum Date |
Jan.
01,
2022
|
|
Total debt |
$ 3
|
$ 3
|