Summary of Significant Accounting Policies (Details) (USD $)	3 Months Ended	6 Months Ended
	Jun. 30, 2012	Jun. 30, 2012	Jun. 30, 2011	Dec. 31, 2011
Summary of Significant Accounting Policies [Line Items]
Estimated annual effective tax rate		38.00%
Effective tax rate		25.00%
Foreign withholding taxes	$ 28,000	$ 11,890,000	$ 7,425,000
U.S. federal statutory rate			35.00%
Excess tax benefits from stock-based compensation	3,239,000	10,850,000	23,000
Cash paid for income taxes		12,400,000
Operating loss carryforwards, federal				69,062,000
Operating loss carryforwards, state				61,493,000
Business acquisition deferred tax asset	1,900,000	1,900,000
Income tax benefit from release of valuation allowance		10,237,000	0
Change in deferred tax liability, business acquisition		$ 8,300,000
Minimum [Member]
Summary of Significant Accounting Policies [Line Items]
Vesting period of equity awards		2 years
Useful life of patents and patent rights		1 year
Maximum [Member]
Summary of Significant Accounting Policies [Line Items]
Vesting period of equity awards		4 years
Useful life of patents and patent rights		10 years