Goodwill (Details) - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016
Goodwill
Balance at December 31, 2016	$ 34,510
Additions to goodwill	0
Impairment	0
Balance at June 30, 2017	34,510
Intangible assets with definite lives
Intangible asset amortization	375	$ 411
Intangible assets with definite lives
Intangible assets with definite lives
Balance at December 31, 2016	3,302
Intangible asset amortization	(375)
Balance at June 30, 2017	$ 2,927