Goodwill and Intangible Assets (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended		12 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016	Dec. 31, 2016
Goodwill, Gross
Balance, beginning of period			$ 58,397
Additions			143,642
Purchase accounting adjustments			(1,865)
Foreign currency fluctuations			19,632
Balance, end of period	$ 219,806		219,806		$ 58,397
Accumulated Impairment Losses
Balance, beginning of period			(37,332)
Foreign currency fluctuations			(3,426)
Balance, end of period	(40,758)		(40,758)		(37,332)
Goodwill, Net
Balance, beginning of period			21,065
Additions			143,642
Purchase accounting adjustments			(1,865)
Foreign currency fluctuations			16,206
Balance, end of period	179,048		179,048		21,065
Acquired Finite-lived Intangible Assets
Original cost	193,522		193,522		15,152
Accumulated amortization	(17,770)		(17,770)		(8,692)
Intangible Assets, Net	175,752		175,752		6,460
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Finite-Lived Intangibles	159,445		159,445
Purchase of Intangible Assets			$ 2,500	$ 0
Finite-Lived Intangible Asset, Useful Life			5 years
Amortization expense	7,650	$ 99	$ 11,430	$ 323
Estimated aggregate amortization expense of Intangible Assets
Remaining 2017	5,635		5,635
2018	22,042		22,042
2019	21,398		21,398
2020	19,928		19,928
2021	18,315		18,315
Thereafter	88,434		88,434
Total	175,752		175,752
Customer Lists
Acquired Finite-lived Intangible Assets
Original cost	147,582		147,582		8,016
Accumulated amortization	(13,492)		(13,492)		(5,948)
Intangible Assets, Net	134,090		$ 134,090		$ 2,068
Weighted-average original life			15 years		15 years
Trade Names
Acquired Finite-lived Intangible Assets
Original cost	31,515		$ 31,515		$ 2,000
Accumulated amortization	(1,631)		(1,631)		0
Intangible Assets, Net	29,884		$ 29,884		$ 2,000
Weighted-average original life			10 years		15 years
Technology
Acquired Finite-lived Intangible Assets
Original cost	14,425		$ 14,425		$ 5,136
Accumulated amortization	(2,647)		(2,647)		(2,744)
Intangible Assets, Net	$ 11,778		$ 11,778		$ 2,392
Weighted-average original life			11 years		13 years