Unaudited Consolidated Statements of Comprehensive Income - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Statement of Comprehensive Income [Abstract]
Net income	$ 6,639	$ 7,088	$ 21,739	$ 19,609
Change in fair value of interest rate swap agreements	20	337	89	(235)
Other comprehensive (loss) income, net of tax	20	337	89	(235)
Comprehensive income	$ 6,659	$ 7,425	$ 21,828	$ 19,374