Property and Equipment (Details Textual) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Property and Equipment (Textual) [Abstract]
Depreciation expense	$ 89.9	$ 87.5	$ 79.8
Assets under capital leases	17.1	17.1
Accumulated amortization related to capital leases	11.2	10.1
Depreciation expense related to capital leases	$ 1.0	$ 1.0	$ 1.3