Goodwill and Intangible Assets (Intangible assets) (Details) - USD ($)
$ in Thousands
9 Months Ended
Sep. 30, 2017
Dec. 31, 2016
Intangible assets    
Gross Carrying Amount $ 36,978 $ 30,519
Accumulated Amortization (11,303) (7,399)
Intangible assets, net $ 25,675 23,120
Weighted average amortization period 7 years 6 months  
Developed technology    
Intangible assets    
Gross Carrying Amount $ 18,187 16,618
Accumulated Amortization (8,122) (5,738)
Intangible assets, net $ 10,065 10,880
Weighted average amortization period 5 years 4 months 24 days  
Customer relationships    
Intangible assets    
Gross Carrying Amount $ 11,720 9,196
Accumulated Amortization (2,197) (1,160)
Intangible assets, net $ 9,523 8,036
Weighted average amortization period 8 years 3 months 18 days  
Trademark/trade name    
Intangible assets    
Gross Carrying Amount $ 6,776 4,410
Accumulated Amortization (728) (337)
Intangible assets, net $ 6,048 4,073
Weighted average amortization period 12 years  
Non-competition agreements    
Intangible assets    
Gross Carrying Amount $ 295 295
Accumulated Amortization (256) (164)
Intangible assets, net $ 39 $ 131
Weighted average amortization period 2 years