Supplemental Consolidated Balance Sheet and Statement of Operations Information - Other Income, Net (Details) - USD ($) $ in Thousands	3 Months Ended	12 Months Ended
Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Other Nonoperating Income (Expense) [Abstract]
Income from training reimbursement program									$ 0	$ 0	$ 1,578
Gains (losses) on foreign currency transactions									(609)	289	(372)
Other									45	224	(9)
Other Income, net	$ (305)	$ 24	$ (111)	$ (172)	$ 318	$ (138)	$ 213	$ 120	$ (564)	$ 513	$ 1,197

Amount before tax of foreign currency transaction realized and unrealized gain (loss) recognized in the income statement.

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