CONSOLIDATED STATEMENTS OF STOCKHOLDERS' EQUITY (USD $) In Thousands, except Share data, unless otherwise specified	Total	Common Stock	Additional Paid-in Capital	Retained Earnings (Accumulated Deficit)	Treasury Stock	Accumulated Other Comprehensive Income (Loss)	Class A Stock Common Stock
Balance at Dec. 31, 2012	$ 1,245,385	$ 95	$ 1,763,508	$ (517,054)	$ 0	$ (1,166)	$ 2
Balance (shares) at Dec. 31, 2012		95,223,000			0		2,069,000
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of Common Stock in connection with exercise of stock options	42,625	3	42,622
Issuance of Common Stock in connection with exercise of stock options (shares)		2,641,000
Common Stock tendered upon exercise of stock options in connection with employee tax obligations	(166,358)	(1)	(166,357)
Common Stock tendered upon exercise of stock options in connection with employee tax obligations (in shares)		(597,000)
Issuance of Common Stock in connection with Company 401(k) Savings Plan contribution	0	0
Issuance of Common Stock in connection with Company 401(k) Savings Plan contribution (in shares)		38,000
Issuance of restricted Common Stock under Long-Term Incentive Plan	0	0
Issuance of restricted Common Stock under Long-Term Incentive Plan (in shares)		6,000
Conversion of Class A Stock to Common Stock (in shares)		40,000					(40,000)
Stock-based compensation charges	144,808		144,808
Excess tax benefit from stock-based compensation	97,840		97,840
Net income	327,556
Other comprehensive income, net of tax	(1,685)					(1,685)
Balance at Sep. 30, 2013	1,690,171	97	1,882,421	(189,498)	0	(2,851)	2
Balance (shares) at Sep. 30, 2013		97,351,000			0		2,029,000
Balance at Dec. 31, 2013	1,952,076	97	2,045,857	(92,692)	0	(1,188)	2
Balance (shares) at Dec. 31, 2013		97,667,000			0		2,020,000
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of Common Stock in connection with exercise of stock options	79,698	3	79,695
Issuance of Common Stock in connection with exercise of stock options (shares)		2,460,000
Common Stock tendered upon exercise of stock options in connection with employee tax obligations	(175,866)	0	(175,866)
Common Stock tendered upon exercise of stock options in connection with employee tax obligations (in shares)		(526,000)
Issuance of Common Stock in connection with conversion of convertible senior notes	156,373	0	156,373
Issuance of Common Stock in connection with conversion of convertible senior notes (in shares)		522,000
Issuance of Common Stock in connection with Company 401(k) Savings Plan contribution	0	0
Issuance of Common Stock in connection with Company 401(k) Savings Plan contribution (in shares)		21,000
Issuance of restricted Common Stock under Long-Term Incentive Plan	0	0
Issuance of restricted Common Stock under Long-Term Incentive Plan (in shares)		5,000
Conversion of Class A Stock to Common Stock (in shares)		47,000					(47,000)
Stock-based compensation charges	229,692		229,692
Excess tax benefit from stock-based compensation	343,532		343,532
Acquisition of Common Stock in connection with exercise of convertible note hedges	0		43,849		(43,849)
Acquisition of Common Stock in connection with exercise of convertible note hedges (in shares)					(522,000)
Reduction of warrants in connection with conversion of senior notes	(143,041)		(143,041)
Reduction of equity component of convertible senior notes	(156,657)		(156,657)
Net income	237,898			237,898
Other comprehensive income, net of tax	28,083					28,083
Balance at Sep. 30, 2014	$ 2,551,788	$ 100	$ 2,423,434	$ 145,206	$ (43,849)	$ 26,895	$ 2
Balance (shares) at Sep. 30, 2014		100,196,000			(522,000)		1,973,000