Stockholders' Equity - Accumulated Other Comprehensive Loss (Details) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Accumulated Other Comprehensive Income (Loss) [Line Items]
Stockholders' equity	$ 372,576	$ 416,080	$ 335,145	$ 443,903
Foreign currency translation adjustments
Accumulated Other Comprehensive Income (Loss) [Line Items]
Stockholders' equity	(31,695)	(12,355)
Unrealized gain (loss) on hedging activity
Accumulated Other Comprehensive Income (Loss) [Line Items]
Stockholders' equity	2,914	(358)
Pension and other postretirement benefit plans
Accumulated Other Comprehensive Income (Loss) [Line Items]
Stockholders' equity	(56)	(56)
Accumulated Other Comprehensive Income
Accumulated Other Comprehensive Income (Loss) [Line Items]
Stockholders' equity	$ (28,837)	$ (12,769)	$ (4,373)	$ (5,559)