Accumulated Other Comprehensive Loss (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014	Dec. 31, 2014
Components of comprehensive income
Net income	$ 5,676	$ 5,426	$ 10,600	$ 15,636
Minimum pension liability adjustments			946
Reclassification to interest expense		225	678	710
Deferred income tax expense		(83)	(585)	(245)
Mark to market of interest rate hedges		3	(15)	(35)
Comprehensive income	$ 5,676	$ 5,571	$ 11,624	$ 16,066
Accumulated other comprehensive loss
Mark to market of interest rate hedges, net of tax benefit					$ (422)
Minimum pension liability adjustments, net of tax benefit					(602)
Accumulated other comprehensive loss					$ (1,024)