CONSOLIDATED STATEMENT OF CHANGES IN SHAREHOLDERS' EQUITY - USD ($) $ in Thousands	Cumulative Effect, Period of Adoption, Adjustment [Member] Retained Earnings/(Accumulated Deficit) [Member]	Cumulative Effect, Period of Adoption, Adjustment [Member]	Common Stock [Member]	Treasury Stock [Member]	Additional Paid-in Capital [Member]	Retained Earnings/(Accumulated Deficit) [Member]	Accumulated Other Comprehensive (Loss)/Income [Member]	Total
Balance at Dec. 31, 2018			$ 56,446	$ (866)	$ 366,181	$ (817)	$ (14,168)	$ 406,776
Balance, shares at Dec. 31, 2018			56,446,088
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income						17,930		17,930
Common stock issued from restricted units, net of tax benefits			$ 122		(122)
Common stock issued from restricted units, net of tax benefits, shares			121,916
Stock-based compensation					1,424			1,424
Other comprehensive income net of reclassification adjustments and tax							8,650	8,650
Balance at Mar. 31, 2019			$ 56,568	(866)	367,483	17,113	(5,518)	434,780
Balance (in shares) at Mar. 31, 2019			56,568,004
Balance at Dec. 31, 2018			$ 56,446	(866)	366,181	(817)	(14,168)	406,776
Balance, shares at Dec. 31, 2018			56,446,088
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income								49,705
Other comprehensive income net of reclassification adjustments and tax								23,296
Balance at Sep. 30, 2019			$ 56,911	(866)	370,113	48,888	9,128	484,174
Balance (in shares) at Sep. 30, 2019			56,910,521
Balance at Mar. 31, 2019			$ 56,568	(866)	367,483	17,113	(5,518)	434,780
Balance, shares at Mar. 31, 2019			56,568,004
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income						11,350		11,350
Common stock issued from restricted units, net of tax benefits			$ 307		(307)
Common stock issued from restricted units, net of tax benefits, shares			306,952
Stock-based compensation					1,595			1,595
Other comprehensive income net of reclassification adjustments and tax							10,407	10,407
Balance at Jun. 30, 2019			$ 56,875	(866)	368,771	28,463	4,889	458,132
Balance (in shares) at Jun. 30, 2019			56,874,956
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income						20,425		20,425
Common stock issued from restricted units, net of tax benefits			$ 36		(36)
Common stock issued from restricted units, net of tax benefits, shares			35,565
Stock-based compensation					1,378			1,378
Other comprehensive income net of reclassification adjustments and tax							4,239	4,239
Balance at Sep. 30, 2019			$ 56,911	(866)	370,113	48,888	9,128	484,174
Balance (in shares) at Sep. 30, 2019			56,910,521
Balance at Dec. 31, 2019	$ (2,373)	$ (2,373)	$ 56,941	(866)	371,633	50,742	6,047	$ 484,497
Balance, shares at Dec. 31, 2019			56,940,521					56,940,521
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income						12,591		$ 12,591
Common stock issued from option exercises, net of tax benefits			$ 74		546			620
Common stock issued from option exercises, net of tax benefits, shares			74,000
Common stock issued from restricted units, net of tax benefits			$ 411		(411)
Common stock issued from restricted units, net of tax benefits, shares			411,035
Stock-based compensation					1,216			1,216
Other comprehensive income net of reclassification adjustments and tax							1,553	1,553
Balance at Mar. 31, 2020			$ 57,426	(866)	372,984	60,960	7,600	498,104
Balance (in shares) at Mar. 31, 2020			57,425,556
Balance at Dec. 31, 2019	$ (2,373)	$ (2,373)	$ 56,941	(866)	371,633	50,742	6,047	$ 484,497
Balance, shares at Dec. 31, 2019			56,940,521					56,940,521
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income								$ 55,913
Other comprehensive income net of reclassification adjustments and tax								14,654
Balance at Sep. 30, 2020			$ 57,591	(866)	376,751	104,282	20,701	$ 558,459
Balance (in shares) at Sep. 30, 2020			57,590,874					57,590,874
Balance at Mar. 31, 2020			$ 57,426	(866)	372,984	60,960	7,600	$ 498,104
Balance, shares at Mar. 31, 2020			57,425,556
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income						20,068		20,068
Common stock issued from option exercises, net of tax benefits			$ 129		(129)
Common stock issued from option exercises, net of tax benefits, shares			129,752
Stock-based compensation					1,723			1,723
Other comprehensive income net of reclassification adjustments and tax							13,184	13,184
Balance at Jun. 30, 2020			$ 57,555	(866)	374,578	81,028	20,784	533,079
Balance (in shares) at Jun. 30, 2020			57,555,308
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income						23,254		23,254
Common stock issued from restricted units, net of tax benefits			$ 36		(36)
Common stock issued from restricted units, net of tax benefits, shares			35,566
Stock-based compensation					2,209			2,209
Other comprehensive income net of reclassification adjustments and tax							(83)	(83)
Balance at Sep. 30, 2020			$ 57,591	$ (866)	$ 376,751	$ 104,282	$ 20,701	$ 558,459
Balance (in shares) at Sep. 30, 2020			57,590,874					57,590,874