Goodwill, Customer Relationships and Trademarks - Goodwill and Intangible Assets (Details) - USD ($) $ in Thousands	Jun. 30, 2017	Dec. 31, 2016
Goodwill and Intangible Assets Disclosure [Abstract]
Goodwill	$ 80,947	$ 79,147
Finite-Lived Intangible Assets [Line Items]
Total	39,541
Customer Relationships - Acquired
Finite-Lived Intangible Assets [Line Items]
Cost	64,671	63,571
Accumulated amortization	(37,476)	(31,660)
Total	27,195	31,911
Customer Relationships - Others
Finite-Lived Intangible Assets [Line Items]
Cost	9,828	4,320
Accumulated amortization	(3,580)	(2,708)
Total	6,248	1,612
Trademarks
Finite-Lived Intangible Assets [Line Items]
Cost	6,770	6,770
Accumulated amortization	(672)	(431)
Total	$ 6,098	$ 6,339