Repurchases of Common Stock (Details) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Equity [Abstract]
Shares of common stock repurchases authorized (in shares)	73,000,000.0
Remaining shares available for repurchase under authorization (in shares)	6,300,000
Share repurchased during the period (in shares)	721,000	1,215,000	1,773,000
Shares acquired through employee surrender for statutory tax withholding (in shares)	58,000	39,000	52,000
Total shares repurchased (in shares)	779,000	1,254,000	1,825,000
Cost of shares repurchased in the open market	$ 179,623	$ 303,838	$ 368,691
Cost of shares for employee surrenders	20,603	8,054	9,375
Total cost of shares	$ 200,226	$ 311,892	$ 378,066
Average cost per share - open market repurchases (in USD per share)	$ 249.20	$ 249.84	$ 207.92
Average cost per share - employee surrenders (in USD per share)	354.98	210.10	182.18
Average cost per share - total (in USD per share)	$ 257.08	$ 248.62	$ 207.19