Property and Equipment (Details Textual) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Property Plant and Equipment (Textual) [Abstract]
Capital expenditures incurred for purchase and construction of assets	$ 107,200	$ 97,700
Capital Expenditures Incurred but Not yet Paid	32,720	21,166	$ 11,155
Assets Held-for-sale, Long Lived	1,400	4,000
Depreciation and amortization	47,200	42,300	$ 35,800
Building recorded under capital lease included in property plant equipment before accumulated depreciation	69,600	67,500
Land and Building [Member]
Property Plant and Equipment (Textual) [Abstract]
Acquisition of fixed assets	24,600	62,700
Dealership Acquisitions [Member]
Property Plant and Equipment (Textual) [Abstract]
Acquisition of fixed assets	9,800	80,500
Dealership Acquisitions [Member] | Land [Member]
Property Plant and Equipment (Textual) [Abstract]
Acquisition of fixed assets	$ 8,500	34,200
Dealership Acquisitions [Member] | Buildings [Member]
Property Plant and Equipment (Textual) [Abstract]
Acquisition of fixed assets		$ 41,000