Consolidated Statements of Stockholders' Equity - USD ($) $ in Thousands	Common Stock	Additional Paid-In Capital	Retained Earnings	Accumulated other comprehensive Income (loss)	Treasury Stock	Total
Balance, beginning at Dec. 31, 2016	$ 1,395	$ 2,484,251	$ 78,850	$ (88,011)		$ 2,476,485
Balance (in shares) at Dec. 31, 2016	139,530,654
Increase (Decrease) in Stockholders' Equity
Net income			183,682			183,682
Cash dividends declared			(122,810)			(122,810)
Equity-based awards	$ 1	5,982	(545)		$ (282)	5,156
Equity-based awards (in shares)	42,167
Other comprehensive income (loss), net of tax				(8,372)		(8,372)
Distributions		(2,118)				(2,118)
Common stock issued under Employee Stock Purchase Plan		528				528
Common stock issued under Employee Stock Purchase Plan (in shares)	15,961
Balance, ending at Dec. 31, 2017	$ 1,396	2,488,643	139,177	(96,383)	(282)	2,532,551
Balance (in shares) at Dec. 31, 2017	139,588,782
Increase (Decrease) in Stockholders' Equity
Adoption of Accounting Standards Update No. 2018-02			20,068	(20,068)
Net income			264,394			264,394
Cash dividends declared			(131,036)			(131,036)
Equity-based awards	$ 1	6,868	(684)		(53)	6,132
Equity-based awards (in shares)	43,049
Common stock repurchased					(131,800)	(131,800)
Common stock repurchased (in shares)	(4,769,870)
Other comprehensive income (loss), net of tax				(15,744)		(15,744)
Common stock issued under Employee Stock Purchase Plan		342				342
Common stock issued under Employee Stock Purchase Plan (in shares)	12,341
Balance, ending at Dec. 31, 2018	$ 1,397	2,495,853	291,919	(132,195)	(132,135)	$ 2,524,839
Balance (in shares) at Dec. 31, 2018	134,874,302					134,874,302
Increase (Decrease) in Stockholders' Equity
Net income			284,392			$ 284,392
Cash dividends declared			(138,246)			(138,246)
Equity-based awards	$ 2	7,824	(993)		(1,764)	5,069
Equity-based awards (in shares)	194,187
Common stock repurchased					(136,242)	(136,242)
Common stock repurchased (in shares)	(5,140,010)
Other comprehensive income (loss), net of tax				100,446		100,446
Balance, ending at Dec. 31, 2019	$ 1,399	$ 2,503,677	$ 437,072	$ (31,749)	$ (270,141)	$ 2,640,258
Balance (in shares) at Dec. 31, 2019	129,928,479					129,928,479