Segment Reporting - Long Lived Assets Attributed to Geographic Area (Details) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Long-Lived Assets by Geographical Areas [Line Items]
Long-lived assets	$ 100,701	$ 78,302	$ 57,659
United States
Long-Lived Assets by Geographical Areas [Line Items]
Long-lived assets	54,157	39,973	35,900
Americas-Other
Long-Lived Assets by Geographical Areas [Line Items]
Long-lived assets	13,486	9,447	1,113
Germany
Long-Lived Assets by Geographical Areas [Line Items]
Long-lived assets	23,734	24,637	17,351
Europe-Other
Long-Lived Assets by Geographical Areas [Line Items]
Long-lived assets	6,949	1,146	248
Japan
Long-Lived Assets by Geographical Areas [Line Items]
Long-lived assets	460	517	599
Asia-Other
Long-Lived Assets by Geographical Areas [Line Items]
Long-lived assets	$ 1,915	$ 2,582	$ 2,448