Earnings Per Share (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Basic and Diluted Earnings Per Share Calculations [Abstract]
Net income	$ 9,643	$ 9,420	$ 16,185	$ 16,373
Weighted average shares outstanding (in shares)	26,242	27,504	26,370	27,506
Effect of dilutive potential common shares (in shares)	170	238	202	284
Diluted weighted average shares outstanding (in shares)	26,412	27,742	26,572	27,790
Basic income per share (in dollars per share)	$ 0.37	$ 0.34	$ 0.61	$ 0.60
Diluted income per share (in dollars per share)	$ 0.37	$ 0.34	$ 0.61	$ 0.59