Derivatives And Risk Management (Interest Rate Swap Agreements) (Details) (USD $) In Thousands, unless otherwise specified	9 Months Ended		12 Months Ended	9 Months Ended	12 Months Ended	9 Months Ended	12 Months Ended	9 Months Ended
	Sep. 30, 2013	Sep. 30, 2012	Dec. 31, 2012 June 2013 [Member] Interest Rate Swap Agreements [Member] Caontracts	Sep. 30, 2013 October 2014 [Member] Interest Rate Swap Agreements [Member] Caontracts	Dec. 31, 2012 October 2014 [Member] Interest Rate Swap Agreements [Member] Caontracts	Sep. 30, 2013 October 2015 [Member] Interest Rate Swap Agreements [Member] Caontracts	Dec. 31, 2012 October 2015 [Member] Interest Rate Swap Agreements [Member] Caontracts	Sep. 30, 2013 October 2016 [Member] Interest Rate Swap Agreements [Member] Caontracts	Sep. 30, 2013 June 2018 [Member] Interest Rate Swap Agreements [Member] Caontracts
Derivatives, Fair Value [Line Items]
Cash received (paid) for settlement of interest rate swap agreements	$ (2,901)	$ 18,547
Number of contracts			2	2	2	2	1	1	2,000
Derivative, Notional Amount			$ 85,000	$ 50,000	$ 50,000	$ 45,000	$ 25,000	$ 20,000	$ 50,000
Derivative, Maturity Date			Jun. 01, 2013	Oct. 01, 2014	Oct. 01, 2014	Oct. 01, 2015	Oct. 01, 2015	Oct. 01, 2016	Jun. 01, 2018