CONSOLIDATED STATEMENTS OF STOCKHOLDERS' EQUITY (Unaudited) - USD ($) $ in Thousands	Total	Cumulative Effect of the Change in Accounting Principle	[1]	Common Stock	Additional Paid-in Capital	Accumulated Retained Earnings	Accumulated Retained Earnings Cumulative Effect of the Change in Accounting Principle	[1]	Accumulated Other Comprehensive Income (Loss)
Balance at beginning of period (in shares) at Dec. 31, 2019				59,506,057
Balance at beginning of period at Dec. 31, 2019	$ 2,012,594	$ (45,625)		$ 586	$ 1,594,434	$ 396,051	$ (45,625)		$ 21,523
Increase (Decrease) in Stockholders' Equity
Net income (loss)	(6,785)					(6,785)
Other comprehensive income (loss)	24,140								24,140
Cash dividends declared ($0.96 per common share)	(53,464)					(53,464)
Dividend equivalents declared ($0.96 per restricted stock unit)	0				217	(217)
Share-based compensation expense	7,747				7,747
Issuance of restricted stock, net (in shares)				493,411
Issuance of restricted stock, net	0
Issuance of common stock - acquisition (in shares)				34,407,403
Issuance of common stock - acquisition	749,603			$ 344	749,259
Restricted stock surrendered and canceled (in shares)				(102,486)
Restricted stock surrendered and canceled	(1,372)				(1,372)
Exercise of stock options (in shares)				71,136
Exercise of stock options	1,247				1,247
Balance at end of period (in shares) at Sep. 30, 2020				94,375,521
Balance at end of period at Sep. 30, 2020	2,688,085			$ 930	2,351,532	289,960			45,663
Balance at beginning of period (in shares) at Jun. 30, 2020				94,350,902
Balance at beginning of period at Jun. 30, 2020	2,654,647			$ 930	2,348,415	247,078			58,224
Increase (Decrease) in Stockholders' Equity
Net income (loss)	66,566					66,566
Other comprehensive income (loss)	(12,561)								(12,561)
Cash dividends declared ($0.96 per common share)	(23,590)					(23,590)
Dividend equivalents declared ($0.96 per restricted stock unit)	0				94	(94)
Share-based compensation expense	2,899				2,899
Issuance of restricted stock, net (in shares)				19,902
Issuance of restricted stock, net	0
Restricted stock surrendered and canceled (in shares)				(8,180)
Restricted stock surrendered and canceled	(99)				(99)
Exercise of stock options (in shares)				12,897
Exercise of stock options	223				223
Balance at end of period (in shares) at Sep. 30, 2020				94,375,521
Balance at end of period at Sep. 30, 2020	$ 2,688,085			$ 930	2,351,532	289,960			45,663
Balance at beginning of period (in shares) at Dec. 31, 2020	94,483,136			94,483,136
Balance at beginning of period at Dec. 31, 2020	$ 2,746,649			$ 931	2,354,871	330,555			60,292
Increase (Decrease) in Stockholders' Equity
Net income (loss)	255,058					255,058
Other comprehensive income (loss)	(59,116)								(59,116)
Repurchase and retirement of common stock (in shares)				(479,944)
Repurchase and retirement of common stock	(18,067)			$ (5)	(11,942)	(6,120)
Cash dividends declared ($0.96 per common share)	(90,747)					(90,747)
Dividend equivalents declared ($0.96 per restricted stock unit)	0				361	(361)
Share-based compensation expense	9,911				9,911
Issuance of restricted stock, net (in shares)				450,549
Issuance of restricted stock, net	0			$ 3	(3)
Restricted stock surrendered and canceled (in shares)				(149,782)
Restricted stock surrendered and canceled	(6,354)				(6,354)
Exercise of stock options (in shares)				50,252
Exercise of stock options	$ 782				782
Balance at end of period (in shares) at Sep. 30, 2021	94,354,211			94,354,211
Balance at end of period at Sep. 30, 2021	$ 2,838,116			$ 929	2,347,626	488,385			1,176
Balance at beginning of period (in shares) at Jun. 30, 2021				94,656,575
Balance at beginning of period at Jun. 30, 2021	2,813,419			$ 931	2,352,112	433,852			26,524
Increase (Decrease) in Stockholders' Equity
Net income (loss)	90,088					90,088
Other comprehensive income (loss)	(25,348)								(25,348)
Repurchase and retirement of common stock (in shares)				(280,270)
Repurchase and retirement of common stock	(11,170)			$ (3)	(6,965)	(4,202)
Cash dividends declared ($0.96 per common share)	(31,226)					(31,226)
Dividend equivalents declared ($0.96 per restricted stock unit)	0				127	(127)
Share-based compensation expense	3,349				3,349
Issuance of restricted stock, net (in shares)				14,592
Issuance of restricted stock, net	0			$ 1	(1)
Restricted stock surrendered and canceled (in shares)				(39,755)
Restricted stock surrendered and canceled	(1,046)				(1,046)
Exercise of stock options (in shares)				3,069
Exercise of stock options	$ 50				50
Balance at end of period (in shares) at Sep. 30, 2021	94,354,211			94,354,211
Balance at end of period at Sep. 30, 2021	$ 2,838,116			$ 929	$ 2,347,626	$ 488,385			$ 1,176

[1] Related to the adoption of Accounting Standards Update 2016-13, Financial Instruments - Credit Losses (Topic 326): Measurement of Credit Losses on Financial Instruments.