Property and Equipment (Narrative) (Details) - USD ($)	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Property, Plant and Equipment [Line Items]
Depreciation expense on property and equipment	$ 8,600,000	$ 6,500,000	$ 4,900,000
Property and equipment under capital leases	0	600,000
Accumulated depreciation on property and equipment under capital leases		500,000
Impairment of long-lived assets	0	0	0
Assets Held under Capital Leases
Property, Plant and Equipment [Line Items]
Depreciation expense on property and equipment	$ 0	$ 300,000	$ 500,000