Condensed Consolidated Statements of Changes In Shareholders' Equity - USD ($) $ in Thousands	Total	Cumulative Effect, Period of Adoption, Adjustment	Cumulative Effect, Period Of Adoption, Adjusted Balance	Common Stock	Common Stock Cumulative Effect, Period Of Adoption, Adjusted Balance	Retained Earnings	Retained Earnings Cumulative Effect, Period of Adoption, Adjustment	Retained Earnings Cumulative Effect, Period Of Adoption, Adjusted Balance	Accumulated Other Comprehensive Income (Loss)	Accumulated Other Comprehensive Income (Loss) Cumulative Effect, Period Of Adoption, Adjusted Balance
Beginning balance at Dec. 31, 2019	$ 906,570	$ (12,983)	$ 893,587	$ 543,998	$ 543,998	$ 367,794	$ (12,983)	$ 354,811	$ (5,222)	$ (5,222)
Beginning balance (in shares) at Dec. 31, 2019				30,523,824	30,523,824
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	23,551					23,551
Other comprehensive income (loss)	5,841								5,841
Stock options exercised	288			$ 288
Stock options exercised (in shares)				16,000
RSU vesting	635			$ 635
PSU vesting	296			$ 296
RSUs released (in shares)				29,089
PSUs released (in shares)				20,265
Repurchase of common stock	(25,304)			$ (14,795)		(10,509)
Repurchase of common stock (in shares)				(829,969)
Dividends paid	(13,208)					(13,208)
Ending balance at Jun. 30, 2020	885,686			$ 530,422		354,645			619
Ending balance (in shares) at Jun. 30, 2020				29,759,209
Beginning balance at Mar. 31, 2020	866,426			$ 534,623		356,935			(25,132)
Beginning balance (in shares) at Mar. 31, 2020				29,973,516
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	7,430					7,430
Other comprehensive income (loss)	25,751								25,751
Stock options exercised	140			$ 140
Stock options exercised (in shares)				8,000
RSU vesting	338			$ 338
PSU vesting	154			$ 154
RSUs released (in shares)				28,727
PSUs released (in shares)				20,265
Repurchase of common stock	(8,009)			$ (4,833)		(3,176)
Repurchase of common stock (in shares)				(271,299)
Dividends paid	(6,544)					(6,544)
Ending balance at Jun. 30, 2020	885,686			$ 530,422		354,645			619
Ending balance (in shares) at Jun. 30, 2020				29,759,209
Beginning balance at Dec. 31, 2020	$ 925,114			$ 530,835		381,999			12,280
Beginning balance (in shares) at Dec. 31, 2020	29,727,214			29,727,214
Ending balance at Mar. 31, 2021	$ 942,539			$ 531,367		408,211			2,961
Ending balance (in shares) at Mar. 31, 2021				29,727,122
Beginning balance at Dec. 31, 2020	$ 925,114			$ 530,835		381,999			12,280
Beginning balance (in shares) at Dec. 31, 2020	29,727,214			29,727,214
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	$ 62,011					62,011
Other comprehensive income (loss)	(4,113)								(4,113)
Stock options exercised	$ 28			$ 28
Stock options exercised (in shares)	1,675			1,675
RSU vesting	$ 757			$ 757
PSU vesting	406			$ 406
RSUs released (in shares)				42,712
Repurchase of common stock	(2,561)			$ (988)		(1,573)
Repurchase of common stock (in shares)				(55,307)
Dividends paid	(14,862)					(14,862)
Ending balance at Jun. 30, 2021	$ 966,780			$ 531,038		427,575			8,167
Ending balance (in shares) at Jun. 30, 2021	29,716,294			29,716,294
Beginning balance at Mar. 31, 2021	$ 942,539			$ 531,367		408,211			2,961
Beginning balance (in shares) at Mar. 31, 2021				29,727,122
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	28,362					28,362
Other comprehensive income (loss)	5,206								5,206
Stock options exercised	28			$ 28
Stock options exercised (in shares)				1,675
RSU vesting	405			$ 405
PSU vesting	221			$ 221
RSUs released (in shares)				42,511
PSUs released (in shares)				0
Repurchase of common stock	(2,551)			$ (983)		(1,568)
Repurchase of common stock (in shares)				(55,014)
Dividends paid	(7,430)					(7,430)
Ending balance at Jun. 30, 2021	$ 966,780			$ 531,038		$ 427,575			$ 8,167
Ending balance (in shares) at Jun. 30, 2021	29,716,294			29,716,294