Consolidated Statements of Stockholders' Equity - USD ($) shares in Thousands, $ in Thousands	Total	Common Stock	Additional Paid-In Capital	Accumulated Other Comprehensive Income (Loss)	Retained Earnings
Balance at beginning of period at Dec. 31, 2016	$ 1,086,599	$ 128	$ 1,022,411	$ (20,502)	$ 84,562
Balance at beginning of period, (in shares) at Dec. 31, 2016		127,797
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	290,584				290,584
Other comprehensive income (loss)	24,009			24,009
Dividends declared	(121,082)				(121,082)
Net issuances of restricted stock	0	$ 1	(1)
Net issuances of restricted stock (in shares)		918
Stock-based compensation expense	42,191		42,191
Repurchases of common stock	(217,036)	$ (5)			(217,031)
Repurchases of common stock, (in shares)		(4,454)
Balance at end of period at Dec. 31, 2017	1,105,265	$ 124	1,064,601	3,507	37,033
Balance at end of period, (in shares) at Dec. 31, 2017		124,261
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	434,288				434,288
Other comprehensive income (loss)	(19,616)			(19,616)
Dividends declared	(136,824)		(30,365)		(106,459)
Net issuances of restricted stock	0	$ 1	(1)
Net issuances of restricted stock (in shares)		666
Stock-based compensation expense	44,953		44,953
Repurchases of common stock	(364,868)	$ (6)			(364,862)
Repurchases of common stock, (in shares)		(5,849)
Balance at end of period at Dec. 31, 2018	1,063,198	$ 119	1,079,188	(16,109)	0
Balance at end of period, (in shares) at Dec. 31, 2018		119,078
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	454,433				454,433
Other comprehensive income (loss)	(3,877)			(3,877)
Dividends declared	(145,726)				(145,726)
Net issuances of restricted stock	0	$ 1	(1)
Net issuances of restricted stock (in shares)		647
Stock-based compensation expense	48,300		48,300
Repurchases of common stock	(272,645)	$ (5)			(272,640)
Repurchases of common stock, (in shares)		(4,605)
Balance at end of period at Dec. 31, 2019	$ 1,143,683	$ 115	$ 1,127,487	$ (19,986)	$ 36,067
Balance at end of period, (in shares) at Dec. 31, 2019		115,120