Stockholders' Equity - Preferred and Common Stock (Details) (USD $) In Millions, except Share data, unless otherwise specified	1 Months Ended				1 Months Ended	12 Months Ended		1 Months Ended	12 Months Ended		1 Months Ended	12 Months Ended		1 Months Ended	12 Months Ended		1 Months Ended	12 Months Ended						1 Months Ended
	May 31, 2012	Dec. 31, 2012	May 17, 2012	Dec. 31, 2011	May 31, 2012 Series A Preferred Stock	Dec. 31, 2011 Series A Preferred Stock	May 17, 2012 Series A Preferred Stock	May 31, 2012 Series B Preferred Stock	Dec. 31, 2011 Series B Preferred Stock	May 17, 2012 Series B Preferred Stock	May 31, 2012 Series C Preferred Stock	Dec. 31, 2011 Series C Preferred Stock	May 17, 2012 Series C Preferred Stock	May 31, 2012 Series D Preferred Stock	Dec. 31, 2011 Series D Preferred Stock	May 17, 2012 Series D Preferred Stock	May 31, 2012 Series E Preferred Stock	Dec. 31, 2011 Series E Preferred Stock	May 17, 2012 Series E Preferred Stock	Dec. 31, 2012 Class A Common Stock votes	Dec. 31, 2011 Class A Common Stock	Dec. 31, 2012 Class B Common Stock votes	Dec. 31, 2011 Class B Common Stock	May 30, 2012 Common Class B to Class A
Class of Stock
Conversion of stock into common stock	545,401,443																							335,943,024
Shares Authorized			569,001,000				134,747,000			226,032,000			95,768,000			67,454,000			45,000,000
Shares Issued and Outstanding			543,217,000				133,055,000			224,123,000			91,410,000			50,591,000			44,038,000
Aggregate Liquidation Preference			$ 615	$ 615		$ 1	$ 1		$ 13	$ 13		$ 26	$ 26		$ 375	$ 375		$ 200	$ 200
Dividends Per Share Per Annum					$ 0.00036875	$ 0.00036875		$ 0.00456000	$ 0.00456000		$ 0.02297335	$ 0.02297335		$ 0.59300000	$ 0.59300000		$ 0.36332640	$ 0.36332640
Conversion Ratio Per Share						1.000000	1.000000		1.004910	1.004910		1.004909	1.004909		1.012561	1.012561		1.000000	1.000000
Common stock, shares authorized																				5,000,000,000	4,141,000,000	4,141,000,000	4,141,000,000
Common stock, par value		$ 0.000006		$ 0.000006																$ 0.000006		$ 0.000006
Common stock, number of votes by class																				1		10
Common stock, shares, issued																				1,671,277,621	117,000,000	701,427,574	1,213,000,000
Common stock, shares outstanding																				1,671,277,621	117,000,000	701,427,574	1,213,000,000