CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Statement of Comprehensive Income [Abstract]
Net income (loss)	$ (26,938)	$ 62,042	$ 76,149
Other comprehensive income (loss):
Change in fair value of interest rate swaps	0	(137)	(229)
Net loss reclassified into income on settlement of interest rate swaps	119	1,056	1,090
Other comprehensive income	119	919	861
Total comprehensive income (loss)	$ (26,819)	$ 62,961	$ 77,010