Cash, Cash Equivalents, and Investments - Textuals (Details) (USD $)	3 Months Ended				3 Months Ended					3 Months Ended
	Mar. 31, 2012 investments	Dec. 31, 2011 investments	Apr. 08, 2010	Mar. 31, 2012 Business Acquisition Acquired Entity Ankeena [Member] month	Mar. 31, 2012 Cost Method Investee, Privately Held Companies	Mar. 31, 2011 Cost Method Investee, Privately Held Companies	Dec. 31, 2011 Cost Method Investee, Privately Held Companies	Mar. 31, 2012 Fair Value, Measurements, Nonrecurring [Member] Cost Method Investee, Privately Held Companies	Dec. 31, 2011 Fair Value, Measurements, Nonrecurring [Member] Cost Method Investee, Privately Held Companies	Mar. 31, 2012 Fair Value, Measurements, Nonrecurring [Member] Fair Value, Inputs, Level 3 [Member] Cost Method Investee, Privately Held Companies	Mar. 31, 2011 Fair Value, Measurements, Nonrecurring [Member] Fair Value, Inputs, Level 3 [Member] Cost Method Investee, Privately Held Companies
Total investments In unrealized loss position	89	135
Decrease in Restricted Cash	$ 79,000,000
Business Acquisition, Cash Value of Unvested Restricted Shares			10,700,000	100,000
Business Acquisition, Payments for Restricted Shares That Have Vested				10,600,000
Vesting Period For Restricted Shares				6
Minority equity investment					36,000,000		51,800,000	6,000,000	400,000
Investment in privately-held companies					1,100,000	6,000,000
Cost-method Investments, Other than Temporary Impairment	$ 14,000,000									$ 14,000,000	$ 0