Derivatives And Risk Management (Derivative Instruments Summary) (Details) (USD $)	Dec. 31, 2013	Dec. 31, 2012
Derivatives, Fair Value [Line Items]
Asset	$ 89,132,000	$ 89,297,000
Liability	(89,675,000)	(143,766,000)
Collateral Netting	8,732,000	9,707,000
Net Asset (Liability)	8,189,000	(44,762,000)
Derivative Asset, Fair Value, Amount Not Offset Against Collateral	0	0
Derivative Liability, Fair Value, Amount Not Offset Against Collateral	0	0
Derivative, Fair Value, Net	8,189,000	(44,762,000)
Collateral Already Posted, Aggregate Fair Value	26,100,000	10,100,000
Other Current Liabilities [Member] | Foreign Currency Exchange Contracts [Member]
Derivatives, Fair Value [Line Items]
Asset		7,000
Liability		(34,000)
Collateral Netting		0
Net Asset (Liability)		(27,000)
Derivative Asset, Fair Value, Amount Not Offset Against Collateral		0
Derivative Liability, Fair Value, Amount Not Offset Against Collateral		0
Derivative, Fair Value, Net		(27,000)
Other Current Liabilities [Member] | Interest Rate Contracts [Member]
Derivatives, Fair Value [Line Items]
Asset		0
Liability		(1,406,000)
Collateral Netting		0
Net Asset (Liability)		(1,406,000)
Derivative Asset, Fair Value, Amount Not Offset Against Collateral		0
Derivative Liability, Fair Value, Amount Not Offset Against Collateral		0
Derivative, Fair Value, Net		(1,406,000)
Other Current Liabilities [Member] | Foreign Currency Exchange Contracts [Member]
Derivatives, Fair Value [Line Items]
Asset	7,000
Liability	(6,000)
Collateral Netting	0
Net Asset (Liability)	1,000
Derivative Asset, Fair Value, Amount Not Offset Against Collateral	0
Derivative Liability, Fair Value, Amount Not Offset Against Collateral	0
Derivative, Fair Value, Net	1,000
Other Current Liabilities [Member] | Interest Rate Contracts [Member]
Derivatives, Fair Value [Line Items]
Asset	13,968,000
Liability	0
Collateral Netting	0
Net Asset (Liability)	13,968,000
Derivative Asset, Fair Value, Amount Not Offset Against Collateral	0
Derivative Liability, Fair Value, Amount Not Offset Against Collateral	0
Derivative, Fair Value, Net	13,968,000
Other Property And Investments Net [Member] | Interest Rate Contracts [Member]
Derivatives, Fair Value [Line Items]
Asset	19,575,000	7,265,000
Liability	0	0
Collateral Netting	0	0
Net Asset (Liability)	19,575,000	7,265,000
Derivative Asset, Fair Value, Amount Not Offset Against Collateral	0	0
Derivative Liability, Fair Value, Amount Not Offset Against Collateral	0	0
Derivative, Fair Value, Net	19,575,000	7,265,000
Current Utility Energy Commodity Derivative Assets [Member] | Commodity Contracts [Member]
Derivatives, Fair Value [Line Items]
Asset	7,416,000	10,772,000
Liability	(4,394,000)	(6,633,000)
Collateral Netting	0	0
Net Asset (Liability)	3,022,000	4,139,000
Derivative Asset, Fair Value, Amount Not Offset Against Collateral	0	(9,678,000)
Derivative Liability, Fair Value, Amount Not Offset Against Collateral	0	6,572,000
Derivative, Fair Value, Net	3,022,000	1,033,000
Non-Current Utility Energy Commodity Derivative Assets [Member] | Commodity Contracts [Member]
Derivatives, Fair Value [Line Items]
Asset	7,610,000	18,779,000
Liability	(6,756,000)	(17,686,000)
Collateral Netting	0	0
Net Asset (Liability)	854,000	1,093,000
Derivative Asset, Fair Value, Amount Not Offset Against Collateral	0	0
Derivative Liability, Fair Value, Amount Not Offset Against Collateral	0	0
Derivative, Fair Value, Net	854,000	1,093,000
Current Utility Energy Commodity Derivative Liabilities [Member] | Commodity Contracts [Member]
Derivatives, Fair Value [Line Items]
Asset	23,455,000	50,227,000
Liability	(37,306,000)	(89,449,000)
Collateral Netting	2,976,000	9,707,000
Net Asset (Liability)	(10,875,000)	(29,515,000)
Derivative Asset, Fair Value, Amount Not Offset Against Collateral	0	9,678,000
Derivative Liability, Fair Value, Amount Not Offset Against Collateral	0	(6,572,000)
Derivative, Fair Value, Net	(10,875,000)	(26,409,000)
Other Noncurrent Liabilities [Member] | Commodity Contracts [Member]
Derivatives, Fair Value [Line Items]
Asset	17,101,000	2,247,000
Liability	(41,213,000)	(28,558,000)
Collateral Netting	5,756,000	0
Net Asset (Liability)	(18,356,000)	(26,311,000)
Derivative Asset, Fair Value, Amount Not Offset Against Collateral	0	0
Derivative Liability, Fair Value, Amount Not Offset Against Collateral	0	0
Derivative, Fair Value, Net	$ (18,356,000)	$ (26,311,000)