Accumulated Other Comprehensive Loss - Components Of Accumulated Other Comprehensive Income (Loss) (Details) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Accumulated Other Comprehensive Income (Loss), Net of Tax [Abstract]
Foreign currency translation adjustments	$ (4,010)	$ (2,401)	$ (5,362)
Deferred loss on cash flow hedge	(1,436)	(2,298)	(3,160)
Total accumulated other comprehensive loss	$ (5,446)	$ (4,699)	$ (8,522)