Long-Term Debt Interest Rate Swaps (Details) (USD $)	12 Months Ended				12 Months Ended
	Dec. 31, 2011 Interest Rate Swap [Member]	Oct. 31, 2010 Interest Rate Swap [Member]	Dec. 31, 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]	Dec. 31, 2011 Swap [Member]	Dec. 31, 2010 Swap [Member]	Dec. 31, 2009 Swap [Member]	Dec. 31, 2011 September 2013 [Member] Interest Rate Swap [Member]	Dec. 31, 2011 October 2013 Thru September 2014 [Member] Interest Rate Swap [Member]	Dec. 31, 2011 October 2014 [Member] Interest Rate Swap [Member]
Derivative [Line Items]
Derivative, Notional Amount	$ 200,000,000	$ 348,300,000
Fixed Interest Rate of Swap	1.73%
Quarterly Amortization of Interest Rate Swap Notional Amount								2,500,000	5,000,000	7,500,000
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			(5,078,000)	5,156,000
Other Comprehensive Income (Loss), Derivatives Qualifying as Hedges, Net of Tax					(5,847,000)	2,990,000	0
Deferred Taxes Pertaining To Other Comprehensive Income Relating to Swaps					$ 3,700,000	$ (1,900,000)