Accumulated Other Comprehensive Loss - Changes in Accumulated Other Comprehensive Loss (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning balance	$ (395,899)	$ (428,801)	$ (452,871)
Other comprehensive loss before reclassification	(606)	(2,669)
Amounts reclassified from accumulated other comprehensive income	862	862
Net current period other comprehensive income (loss)	256	(1,807)	(754)
Ending balance	(311,349)	(395,899)	(428,801)
Loss on Cash Flow Hedge
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning balance	(4,022)	(4,884)
Other comprehensive loss before reclassification	0	0
Amounts reclassified from accumulated other comprehensive income	862	862
Net current period other comprehensive income (loss)	862	862
Ending balance	(3,160)	(4,022)	(4,884)
Foreign Currency Items
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning balance	(4,756)	(2,087)
Other comprehensive loss before reclassification	(606)	(2,669)
Amounts reclassified from accumulated other comprehensive income	0	0
Net current period other comprehensive income (loss)	(606)	(2,669)
Ending balance	(5,362)	(4,756)	(2,087)
AOCI Attributable to Parent
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning balance	(8,778)	(6,971)	(6,217)
Ending balance	$ (8,522)	$ (8,778)	$ (6,971)