Accumulated Other Comprehensive Loss - Changes in Accumulated Other Comprehensive Loss, Net of Tax (Details) $ in Thousands	3 Months Ended
	Mar. 31, 2018 USD ($)
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Beginning balance	$ (258,601)
Other comprehensive income before reclassification	855
Amounts reclassified from accumulated other comprehensive loss	215
Net current period other comprehensive income	1,070
Ending balance	(259,917)
Loss on Cash Flow Hedge
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Beginning balance	(2,298)
Other comprehensive income before reclassification	0
Amounts reclassified from accumulated other comprehensive loss	215
Net current period other comprehensive income	215
Ending balance	(2,083)
Foreign Currency Items
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Beginning balance	(2,401)
Other comprehensive income before reclassification	855
Amounts reclassified from accumulated other comprehensive loss	0
Net current period other comprehensive income	855
Ending balance	(1,546)
AOCI Attributable to Parent
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Beginning balance	(4,699)
Ending balance	$ (3,629)