Earnings Per Share (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended						9 Months Ended
	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Sep. 30, 2019	Sep. 30, 2018
Earnings Per Share, [Line Items]
Net income	$ 12,976	$ 13,767	$ 18,720	$ 11,940	$ 10,112	$ 7,287	$ 45,463	$ 29,339
Weighted Average Number of Shares Outstanding, Basic [Abstract]
Weighted average shares outstanding - basic	21,660			21,102			21,348	21,073
Weighted Average Number of Shares Outstanding, Diluted [Abstract]
Weighted average shares outstanding - diluted	22,277			21,721			21,965	21,671
Earnings Per Share, Basic [Abstract]
Earnings per share - basic	$ 0.60			$ 0.57			$ 2.13	$ 1.39
Earnings Per Share, Diluted [Abstract]
Earnings per share - diluted	$ 0.58			$ 0.55			$ 2.07	$ 1.35
Stock option [Member]
Incremental Weighted Average Shares Attributable to Dilutive Effect [Abstract]
Dilutive effect of shares issued under stock compensation arrangements	572			602			581	595
Restricted stock [Member]
Incremental Weighted Average Shares Attributable to Dilutive Effect [Abstract]
Dilutive effect of shares issued under stock compensation arrangements	45			17			36	3