Stock-Based Compensation - Stock Award Activity (Details) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Stock option activity
Total options outstanding, end of period (in shares)	4,312,000
Weighted-Average Exercise Price
Total options outstanding at the end of the period (in dollars per share)	$ 31.39
Stock options
Stock option activity
Total options outstanding, beginning of period (in shares)	6,845,685	11,725,823	14,058,574
Granted (in shares)	1,901,000	452,000	667,750
Exercised (in shares)	(431,092)	(1,884,938)	(2,724,301)
Forfeited and cancelled (in shares)	(392,584)	(3,447,200)	(276,200)
Total options outstanding, end of period (in shares)	7,923,009	6,845,685	11,725,823
Exercisable at the end of the period (in shares)	1,892,809	1,965,585	3,299,023
Weighted-Average Exercise Price
Total options outstanding, beginning of the period (in dollars per share)	$ 31.13	$ 24.51	$ 21.71
Granted (in dollars per share)	54.41	69.11	63.23
Exercised (in dollars per share)	23.36	16.15	18.77
Forfeited and cancelled (in dollars per share)	50.03	21.78	32.26
Total options outstanding at the end of the period (in dollars per share)	36.21	31.13	24.51
Exercisable, Weighted-Average Exercise Price (in dollars per share)	$ 29.97	$ 26.82	$ 19.64
Share-based compensation additional disclosures
Tax benefit from stock awards exercised	$ 5,006	$ 33,716	$ 52,366
Additional disclosures
Aggregate intrinsic value of stock options outstanding	179,314
Aggregate intrinsic value of stock options exercisable	$ 54,664
Stock options | Long-Term Performance Based Plans
Stock option activity
Total options outstanding, beginning of period (in shares)	3,904,500	7,246,500
Total options outstanding, end of period (in shares)	4,312,000	3,904,500	7,246,500
Weighted-Average Exercise Price
Total options outstanding, beginning of the period (in dollars per share)	$ 28.03	$ 24.14
Total options outstanding at the end of the period (in dollars per share)	$ 31.39	$ 28.03	$ 24.14