Annual report pursuant to Section 13 and 15(d)

CONSOLIDATED BALANCE SHEETS (Parenthetical)

v3.10.0.1
CONSOLIDATED BALANCE SHEETS (Parenthetical) - shares
shares in Millions
Dec. 31, 2018
Dec. 31, 2017
Dec. 31, 2016
Dec. 31, 2015
Treasury stock, shares 1 1    
Common Stock | Class A Common Stock:        
Common stock, shares issued 163 173 180 194
Common Stock | Class B Common Stock:        
Common stock, shares issued 696 687 689 693