Accumulated Other Comprehensive Income - Reclassifications from Accumulated Other Comprehensive Income and Included in Earnings (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Beginning balance	$ 207,163	$ 427,569
Amount reclassified and recognized in net income or loss, net of tax	544	476
Net change in other comprehensive income, net of tax	(544)	(574)
Ending balance	199,456	433,317
Accumulated other comprehensive income
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Beginning balance	544	6,661
Ending balance	0	6,087
Unrealized loss (gain) reclassified and recognized in net loss, net of tax
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Beginning balance	544
Amount reclassified and recognized in net income or loss, net of tax	(17)	481
Unrealized gain reclassified and recognized in net loss, net of tax	0	(109)
Ending balance	0
Unrealized gain reclassified to accumulated deficit, net of tax
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Amount reclassified and recognized in net income or loss, net of tax	561	0
Foreign currency translation
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Beginning balance	0
Amount reclassified and recognized in net income or loss, net of tax	0	(5)
Unrealized gain reclassified and recognized in net loss, net of tax	0	$ 11
Ending balance	$ 0