CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (UNAUDITED) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014
Comprehensive income:
Net income	$ 12,512	$ 12,022	$ 34,779	$ 36,257
Derivative instruments:
Reclassification of losses to net income, net of tax of $12 and $25 for each of the three and six months ended June 30, 2015 and 2014, respectively	19	19	38	37
Other comprehensive income	19	19	38	37
Comprehensive income	$ 12,531	$ 12,041	$ 34,817	$ 36,294