Consolidated Balance Sheet (Parenthetical) (USD $) In Millions, except Share data, unless otherwise specified	Mar. 31, 2012	Dec. 31, 2011
Finite-Lived Intangible Assets, Accumulated Amortization	$ 595	$ 557
Class A treasury stock, shares	11,797,669	11,153,333
Class A Common Stock [Member]
Common stock, par value	$ 0.0001	$ 0.0001
Common stock, authorized	3,000,000,000	3,000,000,000
Common stock, issued	133,142,745	132,771,392
Common stock, outstanding	121,345,076	121,618,059
Class B Common Stock [Member]
Common stock, par value	$ 0.0001	$ 0.0001
Common stock, authorized	1,200,000,000	1,200,000,000
Common stock, issued	5,146,301	5,245,676
Common stock, outstanding	5,146,301	5,245,676