Goodwill and Intangible Assets - Amortization of Intangible Assets (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016
Intangible Assets
Total amortization	$ 1,396	$ 3,114	$ 3,233	$ 6,146
Service costs
Intangible Assets
Total amortization	755	1,786	2,058	3,486
Accelerated amortization of intangible assets	100	400	600	500
Sales and marketing
Intangible Assets
Total amortization	196	948	339	1,897
Product development
Intangible Assets
Total amortization	268	246	515	493
General and administrative
Intangible Assets
Total amortization	$ 177	$ 134	$ 321	$ 270