Consolidated Statements of Changes in Stockholders' Equity - USD ($) $ in Thousands		Total	Preferred stock	Common stock	Additional paid-in capital	Legal surplus	Retained earnings	Retained earnings Cumulative effect adjustment	Retained earnings Cumulative effect, adjusted balance	Treasury stock	Accumulated other comprehensive income (loss), net of tax
Beginning balance at Dec. 31, 2018			$ 92,000		$ 619,381	$ 90,167	$ 253,040		$ 252,304	$ (103,633)	$ (10,963)
Beginning balance (Topic 326 adoption) at Dec. 31, 2018								$ (736)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stock-based compensation expense					2,134
Lapsed restricted stock units and options										1,294
Transfer from retained earnings						5,612
Net income		$ 53,841					53,841
Cash dividends declared on common stock	[1]						(14,375)
Cash dividends declared on preferred stock							(6,512)
Transfer to legal surplus							(5,612)
Stock repurchased		0
Other comprehensive income (loss), net of tax		9,955									9,955
Ending balance at Dec. 31, 2019		1,045,478	92,000	$ 59,885	621,515	95,779	279,646		254,152	(102,339)	(1,008)
Ending balance (Topic 842 adoption) at Dec. 31, 2019								$ (25,494)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stock-based compensation expense					2,170
Lapsed restricted stock units and options					(1,033)					1,616
Transfer from retained earnings						7,490
Net income		74,327					74,327
Cash dividends declared on common stock	[1]						(14,381)
Cash dividends declared on preferred stock							(6,512)
Transfer to legal surplus							(7,490)
Stock repurchased		(2,226)								(2,226)
Other comprehensive income (loss), net of tax		12,030									12,030
Ending balance at Dec. 31, 2020		1,085,975	92,000	59,885	622,652	103,269	300,096		$ 300,096	(102,949)	11,022
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Redemption of preferred stock			(92,000)
Stock-based compensation expense					6,245
Lapsed restricted stock units and options					(1,966)					2,249
Redemption of preferred stock, issuance costs					10,130		(10,130)
Transfer from retained earnings						14,408
Net income		146,151					146,151
Cash dividends declared on common stock	[1]						(20,505)
Cash dividends declared on preferred stock							(1,255)
Transfer to legal surplus							(14,408)
Stock repurchased		(49,872)								(49,872)
Other comprehensive income (loss), net of tax		(5,862)									(5,862)
Ending balance at Dec. 31, 2021		$ 1,069,160	$ 0	$ 59,885	$ 637,061	$ 117,677	$ 399,949			$ (150,572)	$ 5,160

[1] Dividends declared per common share during the year ended December 31, 2021 - $0.40 (2020 - $0.28; 2019 - $0.28).