Property, plant and equipment (Details) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Dec. 31, 2015
Property, Plant and Equipment [Line Items]
Property, plant and equipment	$ 470,871		$ 421,575
Less: Accumulated depreciation and amortization	(108,327)		(93,767)
Total Property, plant and equipment, net	362,544		327,808
Depreciation and amortization	28,155	$ 25,859
Land and Improvements [Member]
Property, Plant and Equipment [Line Items]
Property, plant and equipment	20,391		16,520
Buildings, Building Improvements and Leasehold Improvements [Member]
Property, Plant and Equipment [Line Items]
Property, plant and equipment	141,322		108,908
Furniture and Equipment [Member]
Property, Plant and Equipment [Line Items]
Property, plant and equipment	191,529		129,933
Software [Member]
Property, Plant and Equipment [Line Items]
Property, plant and equipment	52,744		39,683
Construction-in-progress [Member]
Property, Plant and Equipment [Line Items]
Property, plant and equipment	$ 64,885		$ 126,531