Condensed Consolidated Statements of Stockholders' Equity (Unaudited) - USD ($) shares in Thousands, $ in Thousands	Total	Common stock	Retained earnings	Accumulated other comprehensive income (loss), net
Beginning balance, shares at Dec. 31, 2018		36,874
Beginning balance at Dec. 31, 2018	$ 760,723	$ 591,806	$ 176,372	$ (7,455)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Restricted stock awards forfeited, shares		49
Restricted stock units vested, net of forfeitures of restricted stock awards	0
Exercise of stock options, shares		2
Exercise of stock options	22	$ 22
Stock-based compensation expense	741	$ 741
Common stock repurchased, shares		(26)
Common stock repurchased	(802)	$ (802)
Net income	16,552		16,552
Other comprehensive income (loss), net of tax	8,016			8,016
Cash dividends declared on common stock	(6,662)		(6,662)
Ending balance, shares at Mar. 31, 2019		36,899
Ending balance at Mar. 31, 2019	778,191	$ 591,767	185,863	561
Beginning balance, shares at Dec. 31, 2018		36,874
Beginning balance at Dec. 31, 2018	760,723	$ 591,806	176,372	(7,455)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	16,552
Ending balance, shares at Dec. 31, 2019		36,619
Ending balance at Dec. 31, 2019	809,311	$ 586,459	212,474	10,378
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Exercise of stock options, shares		5
Exercise of stock options	71	$ 71
Stock-based compensation expense	969	$ 969
Common stock repurchased, shares		(822)
Common stock repurchased	(19,060)	$ (19,060)
Net income	12,191		12,191
Other comprehensive income (loss), net of tax	7,914			7,914
Cash dividends declared on common stock	(7,343)		$ (7,343)
Ending balance at Mar. 31, 2020	$ 798,438			18,292
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Effects of implementation of accounting change related to operating leases				$ 0