Selected Quarterly Financial Data (Unaudited) - Stock Based Compensation - Stock Option Activity (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended								6 Months Ended		9 Months Ended			12 Months Ended
	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Sep. 30, 2013	Mar. 31, 2013	Jun. 30, 2015	Jun. 30, 2014	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2013	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Outstanding, Beginning balance			6,386,000			9,228,000		9,727,000	6,386,000	9,228,000	6,386,000	9,228,000	9,727,000	6,386,000	9,228,000	9,727,000
Outstanding, Beginning balance (in per share)			$ 11.44			$ 4.45		$ 4.22	$ 11.44	$ 4.45	$ 11.44	$ 4.45	$ 4.22	$ 11.44	$ 4.45	$ 4.22
Weighted Average Remaining Contractual Term (Years)											3 years 3 months 22 days			3 years 4 months 28 days	2 years 5 months 23 days
Aggregate Intrinsic Value (in thousands)	$ 38,007		$ 132,985								$ 38,007			$ 80,868	$ 158,097
Granted (in shares)											577,000			1,016,000	1,475,000	321,000
Granted (in per share)											$ 45.91			$ 37.60	$ 28.59	$ 15.76
Exercised (in shares)											(2,519,000)			(2,519,000)	(4,226,000)	(630,000)
Exercised (in per share)											$ 4.09			$ 4.09	$ 1.91	$ 4.18
Forfeited or expired (in shares)											(106,000)			(121,000)	(91,000)	(190,000)
Forfeited or expired (in per share)											$ 34.30			$ 34.78	$ 22.56	$ 13.10
Outstanding, Ending balance	4,338,000										4,338,000			4,762,000	6,386,000	9,228,000
Outstanding, Ending balance (in per share)	$ 19.75										$ 19.75			$ 20.33	$ 11.44	$ 4.45
Exercisable, Ending balance (in shares)	2,419,000										2,419,000			2,510,000
Exercisable, Ending balance (in per share)	$ 10.88										$ 10.88			$ 11.28
Exercisable, contractual term											1 year 7 months 13 days			1 year 5 months 5 days
Exercisable, aggregate intrinsic value	$ 42,636		$ 87,991								$ 42,636			$ 65,341
2014 and 2003 Stock Option Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Outstanding, Beginning balance	4,312,000	4,398,000	6,386,000	9,962,000	9,167,000	9,228,000			6,386,000	9,228,000	6,386,000	9,228,000		6,386,000	9,228,000
Outstanding, Beginning balance (in per share)	$ 19.50	$ 17.28	$ 11.44	$ 6.42	$ 4.45	$ 4.45			$ 11.44	$ 4.45	$ 11.44	$ 4.45		$ 11.44	$ 4.45
Weighted Average Remaining Contractual Term (Years)			3 years 4 months 6 days			1 year 4 months 10 days			3 years 5 months 27 days	2 years 9 months		3 years 7 days			2 years 5 months 23 days	1 year 7 months 10 days
Aggregate Intrinsic Value (in thousands)		$ 104,178		$ 184,869	$ 267,200	$ 160,919			$ 104,178	$ 267,200		$ 184,869			$ 158,097	$ 186,169
Granted (in shares)			297,000						520,000	991,000		1,295,000
Granted (in per share)			$ 48.05						$ 45.88	$ 24.75		$ 26.92
Exercised (in shares)	(5,000,000,000)	(290,000)	(2,222,000)	(3,242,000)	(182,000)	(56,000)	(145,000)	(177,000)	(2,513,000)	(238,000)	(2,519,000,000,000)	(3,481,000)	(415,000)
Exercised (in per share)			$ 4.17			$ 3.54			$ 4.07	$ 5.26		$ 1.74
Forfeited or expired (in shares)			(63,000)			(5,000)			(81,000)	(19,000)		(43,000)
Forfeited or expired (in per share)			$ 35.03			$ 12.44			$ 33.16	$ 15.48		$ 19.66
Outstanding, Ending balance		4,312,000	4,398,000	6,999,000	9,962,000	9,167,000			4,312,000	9,962,000		6,999,000			6,386,000	9,228,000
Outstanding, Ending balance (in per share)		$ 19.50	$ 17.28	$ 9.86	$ 6.42	$ 4.45			$ 19.50	$ 6.42		$ 9.86			$ 11.44	$ 4.45
Exercisable, Ending balance (in shares)		2,277,000	2,173,000	4,998,000	8,136,000	7,622,000			2,277,000	8,136,000		4,998,000
Exercisable, Ending balance (in per share)		$ 10.07	$ 7.01	$ 4.92	$ 3.47	$ 3.13			$ 10.07	$ 3.47		$ 4.92
Exercisable, contractual term			1 year 29 days			1 year 15 days			1 year 6 months 18 days	2 years 2 months 27 days		1 year 11 months 19 days
Exercisable, aggregate intrinsic value		$ 76,480		$ 156,650	$ 242,324	$ 143,860			$ 76,480	$ 242,324		$ 156,650