Stockholders' Equity - Reclassification out of AOCI (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2018 USD ($)	Dec. 31, 2017 USD ($)	Dec. 31, 2016 USD ($) subsidiary
Reclassification out of AOCI
Other income (expense), net	$ (368)	$ 392	$ (223)
Income tax expense (benefit)	$ (26,746)	$ (37,594)	2,823
Minimum pension liability | Reclassification out of AOCI
Reclassification out of AOCI
Other income (expense), net			(900)
Income tax expense (benefit)			(400)
Foreign Currency Translation | Reclassification out of AOCI
Reclassification out of AOCI
Other income (expense), net			$ 400
South Korea
Reclassification out of AOCI
Number of subsidiaries liquidated | subsidiary			1