Derivative Instruments (Balance Sheet Disclosures) (Details) (USD $)	Sep. 30, 2012	Aug. 08, 2012	Dec. 31, 2011
Interest Rate Cash Flow Hedges
Notional amount of interest rate contract	$ 25,000,000	$ 223,100,000
Interest rate contract losses expected to be reclassified to statements of operation in the next twelve months	400,000
Derivatives, Fair Value
Derivative Assets, Noncurrent			0
Derivative, Cap Interest Rate		3.00%
Interest Rate Contract [Member] | Designated as Hedging Instrument
Derivatives, Fair Value
Derivative, Fair Value, Net	(403,000)		(608,000)
Interest Rate Contract [Member] | Designated as Hedging Instrument | Other Assets [Member]
Derivatives, Fair Value
Derivative Assets, Noncurrent	103,000
Interest Rate Contract [Member] | Designated as Hedging Instrument | Other Liabilities
Derivatives, Fair Value
Derivative liabilities	(364,000)		(310,000)
Interest Rate Contract [Member] | Designated as Hedging Instrument | Other Long-term Liabilities
Derivatives, Fair Value
Derivative liabilities	$ (142,000)		$ (298,000)