Changes in the Company's carrying value of other intangible assets (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Finite-Lived Intangible Assets [Line Items]
Finite-Live Intangible Assets, Net Adjustments During Period		$ 11,442
Finite-lived Intangible Assets [Roll Forward]
Finite-Lived Intangible Assets, Gross, Beginning	$ 27,938	16,522
Intangible Asssets, Gross, Excluding Goodwill, Beginning	30,103	18,687
Finite-Lived Intangible Assets, Accumulated Amortization, Beginning	(9,676)	(6,263)
Intangible Assets, Net Adjustments During Period		11,442
Amortization of Intangible Assets	(3,504)	(3,415)	$ (1,500)
Indefinite-Lived Intangible Assets, Disposals	(841)
Finite-Lived Intangible Assets, Disposals	(841)
Translation	(106)	(24)
Finite-Lived Intangible Assets, Gross, Ending	26,752	27,938	16,522
Intangible Asssets, Gross, Excluding Goodwill, Ending	28,917	30,103	18,687
Finite-Lived Intangible Assets, Accumulated Amortization, Ending	(12,941)	(9,676)	(6,263)
Trademarks [Member]
Finite-Lived Intangible Assets [Line Items]
Finite-Lived Intangible Assets, Transferred From Indefinite Lived		1,340
Finite-lived Intangible Assets [Roll Forward]
Finite-Lived Intangible Assets, Gross, Beginning	6,440	5,100
Indefinite-lived trademarks	2,165	2,165	2,165
Finite-Lived Intangible Assets, Accumulated Amortization, Beginning	(1,054)	(680)
Indefinite-Lived Intangible Assets, Transferred Fo Finite Lived		0
Amortization of Intangible Assets	(474)	(374)
Finite-Lived Intangible Assets, Disposals	0
Translation	0	0
Finite-Lived Intangible Assets, Gross, Ending	6,440	6,440	5,100
Indefinite-Lived Trademarks, ending	(2,165)	(2,165)	(2,165)
Finite-Lived Intangible Assets, Accumulated Amortization, Ending	(1,528)	(1,054)	(680)
Client Relationships [Member]
Finite-Lived Intangible Assets [Line Items]
Finite-Lived Intangible Assets, Transferred From Indefinite Lived		10,102
Finite-lived Intangible Assets [Roll Forward]
Finite-Lived Intangible Assets, Gross, Beginning	20,376	10,300
Finite-Lived Intangible Assets, Accumulated Amortization, Beginning	(7,974)	(5,047)
Amortization of Intangible Assets	(2,932)	(2,929)
Finite-Lived Intangible Assets, Disposals	(841)
Translation	(106)	(24)
Finite-Lived Intangible Assets, Gross, Ending	19,190	20,376	10,300
Finite-Lived Intangible Assets, Accumulated Amortization, Ending	(10,667)	(7,974)	(5,047)
Noncompete Agreements [Member]
Finite-Lived Intangible Assets [Line Items]
Finite-Lived Intangible Assets, Transferred From Indefinite Lived		0
Finite-lived Intangible Assets [Roll Forward]
Finite-Lived Intangible Assets, Gross, Beginning	150	150
Finite-Lived Intangible Assets, Accumulated Amortization, Beginning	(150)	(135)
Amortization of Intangible Assets	0	(15)
Finite-Lived Intangible Assets, Disposals	0
Translation	0	0
Finite-Lived Intangible Assets, Gross, Ending	150	150	150
Finite-Lived Intangible Assets, Accumulated Amortization, Ending	(150)	(150)	(135)
Franchise Rights [Member]
Finite-Lived Intangible Assets [Line Items]
Finite-Lived Intangible Assets, Transferred From Indefinite Lived		0
Finite-lived Intangible Assets [Roll Forward]
Finite-Lived Intangible Assets, Gross, Beginning	972	972
Finite-Lived Intangible Assets, Accumulated Amortization, Beginning	(498)	(401)
Amortization of Intangible Assets	(98)	(97)
Finite-Lived Intangible Assets, Disposals	0
Translation	0	0
Finite-Lived Intangible Assets, Gross, Ending	972	972	972
Finite-Lived Intangible Assets, Accumulated Amortization, Ending	$ (596)	$ (498)	$ (401)