Property and Equipment - Narrative (Details) (USD $)	3 Months Ended			9 Months Ended
	Sep. 30, 2014	Jun. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013
Property, Plant and Equipment [Abstract]
Depreciation expense	$ 7,700,000		$ 7,000,000	$ 21,100,000	$ 20,400,000
Impairment charges	$ 0	$ 884,000	$ 952,000	$ 884,000	$ 952,000