Goodwill and Intangible Assets - Intangible Assets, Net (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017
Acquired Finite-Lived Intangible Assets [Line Items]
Accumulated amortization	$ (102,687)	$ (78,872)
Foreign currency exchange rate fluctuations	(1,122)	(516)
Total intangible assets, net, gross carrying amount	247,495	247,495
Total intangible assets, net, net carrying amount	$ 143,686	168,107
Min
Acquired Finite-Lived Intangible Assets [Line Items]
Useful life (in years)	1 year
Max
Acquired Finite-Lived Intangible Assets [Line Items]
Useful life (in years)	30 years
Customer relationships
Acquired Finite-Lived Intangible Assets [Line Items]
Gross carrying amount	$ 135,234	135,234
Accumulated amortization	(45,029)	(33,988)
Foreign currency exchange rate fluctuations	(1,185)	(787)
Net carrying amount	$ 89,020	$ 100,459
Customer relationships | Min
Acquired Finite-Lived Intangible Assets [Line Items]
Useful life (in years)	1 year	1 year
Customer relationships | Max
Acquired Finite-Lived Intangible Assets [Line Items]
Useful life (in years)	30 years	30 years
Acquired technology
Acquired Finite-Lived Intangible Assets [Line Items]
Gross carrying amount	$ 78,122	$ 74,222
Accumulated amortization	(29,206)	(21,345)
Foreign currency exchange rate fluctuations	42	221
Net carrying amount	48,958	$ 53,098
Finite-Lived Intangible Assets, Period Increase (Decrease)	$ (3,900)
Acquired technology | Min
Acquired Finite-Lived Intangible Assets [Line Items]
Useful life (in years)	3 years	3 years
Acquired technology | Max
Acquired Finite-Lived Intangible Assets [Line Items]
Useful life (in years)	20 years	20 years
Backlog
Acquired Finite-Lived Intangible Assets [Line Items]
Gross carrying amount	$ 21,350	$ 21,350
Accumulated amortization	(20,703)	(17,182)
Foreign currency exchange rate fluctuations	0	0
Net carrying amount	$ 647	$ 4,168
Backlog | Min
Acquired Finite-Lived Intangible Assets [Line Items]
Useful life (in years)	1 year	1 year
Backlog | Max
Acquired Finite-Lived Intangible Assets [Line Items]
Useful life (in years)	4 years	4 years
Trade names
Acquired Finite-Lived Intangible Assets [Line Items]
Gross carrying amount	$ 7,650	$ 7,650
Accumulated amortization	(4,361)	(3,688)
Foreign currency exchange rate fluctuations	17	40
Net carrying amount	$ 3,306	$ 4,002
Trade names | Min
Acquired Finite-Lived Intangible Assets [Line Items]
Useful life (in years)	1 year	1 year
Trade names | Max
Acquired Finite-Lived Intangible Assets [Line Items]
Useful life (in years)	12 years	12 years
Patents
Acquired Finite-Lived Intangible Assets [Line Items]
Gross carrying amount	$ 3,239	$ 3,239
Accumulated amortization	(1,488)	(1,369)
Foreign currency exchange rate fluctuations	4	10
Net carrying amount	$ 1,755	$ 1,880
Patents | Min
Acquired Finite-Lived Intangible Assets [Line Items]
Useful life (in years)	2 years	2 years
Patents | Max
Acquired Finite-Lived Intangible Assets [Line Items]
Useful life (in years)	20 years	20 years
Non-compete
Acquired Finite-Lived Intangible Assets [Line Items]
Gross carrying amount	$ 1,900	$ 1,900
Accumulated amortization	(1,900)	(1,300)
Foreign currency exchange rate fluctuations	0	0
Net carrying amount	$ 0	$ 600
Useful life (in years)	3 years	3 years
In-process technology
Acquired Finite-Lived Intangible Assets [Line Items]
Accumulated amortization		$ 0
Foreign currency exchange rate fluctuations		0
Carrying amount		$ 3,900