CONDENSED CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (LOSS) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Comprehensive income (loss), net of tax:
Net income (loss)	$ 202,326	$ 126,719	$ (23,520)
Other comprehensive income (loss):
Interest rate swaps (a)	2,196	40	1,003
Capitalized swap interest expense (b)	(203)	(217)	(493)
Pension adjustment (c)	(890)
Other comprehensive income (loss)	1,103	(177)	510
Comprehensive income (loss)	203,429	126,542	(23,010)
Comprehensive (income) loss attributable to noncontrolling interests	(23)		(11)
Comprehensive income (loss) attributable to common stockholders	$ 203,406	$ 126,542	$ (23,021)