Long-Term Debt Interest Rate Swaps (Details) (USD $)	3 Months Ended	6 Months Ended						3 Months Ended	6 Months Ended
	Jun. 30, 2010	Jun. 30, 2010	Jun. 30, 2011 June 30 2011 [Member] Interest Rate Swap [Member]	Oct. 31, 2010 June 30 2011 [Member] Interest Rate Swap [Member]	Jun. 30, 2011 Interest Rate Swap [Member]	Jun. 30, 2011 Interest Rate Swap [Member] Fair Value, Measurements, Recurring [Member] Fair Value, Inputs, Level 2 [Member]	Dec. 31, 2010 Interest Rate Swap [Member] Fair Value, Measurements, Recurring [Member] Fair Value, Inputs, Level 2 [Member]	Jun. 30, 2011 Swap [Member]	Jun. 30, 2011 Swap [Member]
Derivative [Line Items]
Derivative, Notional Amount				$ 348,300,000	$ 200,000,000
Fixed Interest Rate of Swap					1.73%
Quarterly Amortization of Interest Rate Swap Notional Amount					2,500,000
Remaining Balance Of Interest Rate Swap Notional Amount					107,500,000
Realized Gain Loss On Derivatives			400,000
Derivative Financial Instruments, Liabilities, Fair Value Disclosure						67,000	5,156,000
Other Comprehensive Income (Loss), Derivatives Qualifying as Hedges, Net of Tax	0	0						(3,541,000)	(2,704,000)
Deferred Taxes Pertaining To Other Comprehensive Income Relating to Swaps								$ (2,400,000)	$ (1,900,000)