Fair Value Measurements and Interest Rate Swaps (Details) (USD $)			6 Months Ended
	Jun. 30, 2012 Accrued Expenses and Other Current Liabilities [Member]	Jun. 30, 2011 Accrued Expenses and Other Current Liabilities [Member]	Jun. 30, 2012 Interest Rate Swap 1 [Member]	Jun. 30, 2012 Interest Rate Swap 2 [Member]	Jun. 30, 2012 Interest Rate Swap 3 [Member]	Jun. 30, 2012 Interest Rate Swap 4 [Member]	Jun. 30, 2012 Interest Rate Swap 5 [Member]
Derivative [Line Items]
Interest rate swap agreement, effective date			Nov. 21, 2011	Nov. 21, 2011	Dec. 21, 2011	Jan. 17, 2012	Jan. 19, 2012
Interest rate swap agreement, notional amount			$ 25,000,000	$ 25,000,000	$ 50,000,000	$ 25,000,000	$ 25,000,000
Interest rate swap agreement, fixed interest rate			1.185%	1.185%	1.10%	1.05%	0.99%
Interest rate swap agreement, termination date			Oct. 19, 2016	Oct. 19, 2016	Oct. 19, 2016	Oct. 19, 2016	Oct. 19, 2016
Derivatives, Fair Value [Line Items]
Estimated fair value, liability	$ (2,608,000)	$ (1,931,000)