Goodwill and Other Intangibles - Summary of the Company’s intangible assets other than goodwill (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015
Schedule of Finite and Indefinite Lived Intangible Assets [Line Items]
Finite-lived intangible assets, gross	$ 48,344	$ 47,860
Accumulated amortization, finite-lived intangible assets	(47,826)	(43,232)
Net book value	518	4,628
Total intangible assets at net book value	$ 1,418	5,528
Customer Relationships [Member]
Schedule of Finite and Indefinite Lived Intangible Assets [Line Items]
Amortization period	10 years
Finite-lived intangible assets, gross	$ 41,419	41,142
Accumulated amortization, finite-lived intangible assets	$ (40,901)	(36,514)
Internally Developed Software [Member]
Schedule of Finite and Indefinite Lived Intangible Assets [Line Items]
Amortization period	7 years
Finite-lived intangible assets, gross	$ 6,925	6,718
Accumulated amortization, finite-lived intangible assets	(6,925)	(6,718)
Trade Names [Member]
Schedule of Finite and Indefinite Lived Intangible Assets [Line Items]
Indefinite-lived intangible assets	$ 900	$ 900