Repurchases of Common Stock (Details) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Equity [Abstract]
Shares of common stock repurchases authorized (in shares)	68,000,000.0
Remaining shares available for repurchase under authorization (in shares)	2,000,000.0
Share repurchased during the period (in shares)	1,215,000	1,773,000	1,749,000
Shares acquired through employee surrender for statutory tax withholding (in shares)	39,000	52,000	57,000
Total shares repurchased (in shares)	1,254,000	1,825,000	1,806,000
Cost of shares repurchased in the open market	$ 303,838	$ 368,691	$ 270,297
Cost of shares for employee surrenders	8,054	9,375	8,074
Total cost of shares	$ 311,892	$ 378,066	$ 278,371
Average cost per share - open market repurchases (in USD per share)	$ 249.84	$ 207.92	$ 154.51
Average cost per share - employee surrenders (in USD per share)	210.10	182.18	142.55
Average cost per share - total (in USD per share)	$ 248.62	$ 207.19	$ 154.13