Restructuring - Restructuring Activities (Details) - USD ($) $ in Thousands	3 Months Ended	20 Months Ended
Mar. 31, 2019	Mar. 31, 2018	Mar. 31, 2019
Restructuring Reserve [Roll Forward]
Restructuring and related charges	$ 1,086	$ 1,789
Restructuring 2017
Restructuring Reserve [Roll Forward]
Restructuring reserve, start	2,412	5,189
Restructuring and related charges	2,866	5,244
Restructuring reserve, foreign currency translation gain (loss)	(4)	20
Restructuring reserve, settled with cash	3,264	4,410	$ 28,900
Restructuring reserve, settled without cash	(151)	2,408	113,600
Restructuring reserve, end	2,161	3,635	2,161
Severance and benefit related costs \| Restructuring 2017
Restructuring Reserve [Roll Forward]
Restructuring reserve, start	1,742	3,864
Restructuring and related charges	495	1,071
Restructuring reserve, foreign currency translation gain (loss)	(5)	20
Restructuring reserve, settled with cash	1,102	2,305
Restructuring reserve, settled without cash	0	0
Restructuring reserve, end	1,130	2,650	1,130
Lease and contract termination costs \| Restructuring 2017
Restructuring Reserve [Roll Forward]
Restructuring reserve, start	359	650
Restructuring and related charges	540	678
Restructuring reserve, foreign currency translation gain (loss)	3	0
Restructuring reserve, settled with cash	310	793
Restructuring reserve, settled without cash	0	0
Restructuring reserve, end	592	535	592
Relocation and other moving costs \| Restructuring 2017
Restructuring Reserve [Roll Forward]
Restructuring reserve, start	0	0
Restructuring and related charges	51	40
Restructuring reserve, foreign currency translation gain (loss)	0	0
Restructuring reserve, settled with cash	0	40
Restructuring reserve, settled without cash	0	0
Restructuring reserve, end	51	0	51
Other restructuring costs \| Restructuring 2017
Restructuring Reserve [Roll Forward]
Restructuring reserve, start	311	675
Restructuring and related charges	1,780	3,455
Restructuring reserve, foreign currency translation gain (loss)	(2)	0
Restructuring reserve, settled with cash	1,852	1,272
Restructuring reserve, settled without cash	(151)	2,408
Restructuring reserve, end	$ 388	$ 450	$ 388

Amount of cash payments made as the result of exit or disposal activities. Excludes payments associated with a discontinued operation or an asset retirement obligation.

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Amount of expenses associated with exit or disposal activities pursuant to an authorized plan. Excludes expenses related to a discontinued operation or an asset retirement obligation.

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Carrying amount (including both current and noncurrent portions of the accrual) as of the balance sheet date pertaining to a specified type of cost associated with exit from or disposal of business activities or restructuring pursuant to a duly authorized plan.

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A roll forward is a reconciliation of a concept from the beginning of a period to the end of a period.

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Amount of decrease in the reserve for full or partial settlement through consideration other than cash.

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Amount of foreign currency translation gain (loss) which decreases (increases) the restructuring reserve.

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