Earnings Per Share (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2020	Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2020	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Basic Net Earnings Per Common Share [Abstract]
Earnings from continuing operations	$ 22,742	$ 36,212	$ 11,842	$ 9,621	$ 12,738	$ 22,654	$ 20,555	$ 13,104	$ 80,417	$ 69,051	$ 56,854
Loss from discontinued operations, net of taxes	$ (13,568)	$ (7,587)	$ (875)	$ (994)	$ (1,220)	$ (7,903)	$ (1,123)	$ (888)	(23,024)	(11,134)	(13,851)
Net earnings available to common stockholders									$ 57,393	$ 57,917	$ 43,003
Weighted average common shares outstanding (in shares)									22,374,123	22,378,414	22,456,480
Earnings from continuing operations per common share (in dollars per share)	$ 1.02	$ 1.62	$ 0.53	$ 0.43	$ 0.57	$ 1.01	$ 0.92	$ 0.58	$ 3.59	$ 3.09	$ 2.53
Loss from discontinued operations per common share (in dollars per share)									(1.02)	(0.50)	(0.62)
Net earnings per common share - Basic (in dollars per share)	$ 0.41	$ 1.28	$ 0.49	$ 0.38	$ 0.51	$ 0.66	$ 0.87	$ 0.54	$ 2.57	$ 2.59	$ 1.91
Diluted Net Earnings Per Common Share [Abstract]
Earnings from continuing operations	$ 22,742	$ 36,212	$ 11,842	$ 9,621	$ 12,738	$ 22,654	$ 20,555	$ 13,104	$ 80,417	$ 69,051	$ 56,854
Loss from discontinued operations, net of taxes	$ (13,568)	$ (7,587)	$ (875)	$ (994)	$ (1,220)	$ (7,903)	$ (1,123)	$ (888)	(23,024)	(11,134)	(13,851)
Net earnings available to common stockholders									$ 57,393	$ 57,917	$ 43,003
Weighted average common shares outstanding (in shares)									22,374,123	22,378,414	22,456,480
Plus incremental shares from assumed conversions [Abstract]
Dilutive effect of restricted stock and performance-based stock (in shares)									452,000	440,000	476,000
Weighted average common shares outstanding - Diluted (in shares)									22,825,885	22,818,451	22,931,723
Earnings from continuing operations per common share (in dollars per share)	$ 1.00	$ 1.59	$ 0.52	$ 0.42	$ 0.56	$ 1.00	$ 0.90	$ 0.57	$ 3.52	$ 3.03	$ 2.48
Loss from discontinued operations per common share (in dollars per share)									(1.01)	(0.49)	(0.60)
Net earnings per common share - Diluted (in dollars per share)	$ 0.40	$ 1.26	$ 0.48	$ 0.38	$ 0.50	$ 0.65	$ 0.85	$ 0.53	$ 2.51	$ 2.54	$ 1.88
Restricted and Performance Shares [Member]
Earnings Per Share [Abstract]
Antidilutive securities excluded from computation of earnings per share (in shares)									268,000	255,000	249,000