Consolidated Statements of Comprehensive Income - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Statement of Comprehensive Income [Abstract]
Net income	$ 35,080	$ 39,096	$ 26,793
Change in fair value of interest rate swap agreements, net of tax	(35)	136	120
Other comprehensive income (loss), net of tax	(35)	136	120
Comprehensive income	$ 35,045	$ 39,232	$ 26,913