Derivative Instruments (Balance Sheet Disclosures) (Details) (USD $)	Jun. 30, 2012	Dec. 31, 2011
Interest Rate Cash Flow Hedges
Notional amount of interest rate swap	$ 25,000,000
Interest rate swap losses expected to be reclassified to statements of operation in the next twelve months	300,000
Interest rate swap | Designated as Hedging Instrument
Derivatives, Fair Value
Derivative liabilities	546,000	608,000
Interest rate swap | Designated as Hedging Instrument | Other Liabilities
Derivatives, Fair Value
Derivative liabilities	341,000	310,000
Interest rate swap | Designated as Hedging Instrument | Other Long-term Liabilities
Derivatives, Fair Value
Derivative liabilities	$ 205,000	$ 298,000