CONSOLIDATED STATEMENTS OF STOCKHOLDERS' EQUITY (Unaudited) - USD ($) $ in Thousands	Common Stock	Additional Paid-In Capital	Retained Earnings Cumulative-effect adjustment of a change in accounting principle, net of tax: ASU No. 2016-13, Financial Instruments - Credit Losses (Topic 326), Measurement of Credit Losses on Financial Instruments	Retained Earnings	Accumulated other comprehensive Income (Loss)	Treasury Stock	Cumulative-effect adjustment of a change in accounting principle, net of tax: ASU No. 2016-13, Financial Instruments - Credit Losses (Topic 326), Measurement of Credit Losses on Financial Instruments	Total
Balance at Dec. 31, 2019	$ 1,399	$ 2,503,677	$ (12,517)	$ 437,072	$ (31,749)	$ (270,141)	$ (12,517)	$ 2,640,258
Balance (in shares) at Dec. 31, 2019	129,928,479
Increase (Decrease) in Stockholders' Equity
Net income				58,914				58,914
Cash dividends declared				(67,547)				(67,547)
Equity-based awards	$ 2	5,594		(626)		(1,661)		3,309
Equity-based awards (in shares)	156,178
Common stock repurchased						(5,000)		(5,000)
Common stock repurchased (in shares)	(217,759)
Other comprehensive income (loss), net of tax					84,480			84,480
Balance at Jun. 30, 2020	$ 1,401	2,509,271		415,296	52,731	(276,802)		2,701,897
Balance (in shares) at Jun. 30, 2020	129,866,898
Balance at Mar. 31, 2020	$ 1,401	2,506,477		429,323	4,129	(276,645)		2,664,685
Balance (in shares) at Mar. 31, 2020	129,827,968
Increase (Decrease) in Stockholders' Equity
Net income				20,049				20,049
Cash dividends declared				(33,765)				(33,765)
Equity-based awards		2,794		(311)		(157)		2,326
Equity-based awards (in shares)	38,930
Other comprehensive income (loss), net of tax					48,602			48,602
Balance at Jun. 30, 2020	$ 1,401	2,509,271		415,296	52,731	(276,802)		2,701,897
Balance (in shares) at Jun. 30, 2020	129,866,898
Balance at Dec. 31, 2020	$ 1,402	2,514,014		473,974	31,604	(276,890)		$ 2,744,104
Balance (in shares) at Dec. 31, 2020	129,912,272							129,912,272
Increase (Decrease) in Stockholders' Equity
Net income				144,434				$ 144,434
Cash dividends declared				(67,448)				(67,448)
Equity-based awards	$ 3	6,776		(449)		(2,845)		3,485
Equity-based awards (in shares)	239,910
Common stock repurchased						(31,928)		(31,928)
Common stock repurchased (in shares)	(1,132,311)
Other comprehensive income (loss), net of tax					(61,306)			(61,306)
Balance at Jun. 30, 2021	$ 1,405	2,520,790		550,511	(29,702)	(311,663)		$ 2,731,341
Balance (in shares) at Jun. 30, 2021	129,019,871							129,019,871
Balance at Mar. 31, 2021	$ 1,405	2,517,048		497,418	(43,435)	(288,806)		$ 2,683,630
Balance (in shares) at Mar. 31, 2021	129,749,890
Increase (Decrease) in Stockholders' Equity
Net income				86,741				86,741
Cash dividends declared				(33,637)				(33,637)
Equity-based awards		3,742		(11)		(471)		3,260
Equity-based awards (in shares)	69,828
Common stock repurchased						(22,386)		(22,386)
Common stock repurchased (in shares)	(799,847)
Other comprehensive income (loss), net of tax					13,733			13,733
Balance at Jun. 30, 2021	$ 1,405	$ 2,520,790		$ 550,511	$ (29,702)	$ (311,663)		$ 2,731,341
Balance (in shares) at Jun. 30, 2021	129,019,871							129,019,871