Goodwill and Intangible Assets - Goodwill Roll Forward (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015
Goodwill [Roll Forward]
Beginning balance, January 1	$ 65,982	$ 33,798
Additions	369	32,184
Ending balance	$ 66,351	$ 65,982