Derivative and Hedging Instruments (Details-5) (USD $)	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012
Counterparties in net liability position or default [Abstract]
Number of counterparties in net liability position	0	0
Number of counterparties in default	0
Commodity Derivative Contracts [Member] | Fuel For Electric Generation Purchased Power [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Realized losses (gains)	$ (564,000)	$ 2,620,000
Commodity Derivative Contracts [Member] | Cost Of Gas Sold Expense [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Realized losses (gains)	868,000	3,072,000
Financial Transmission Rights [Member] | Fuel For Electric Generation Purchased Power [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Realized losses (gains)	(983,000)	(45,000)
Financial Transmission Rights [Member] | Cost Of Gas Sold Expense [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Realized losses (gains)	0	0
Ten-year PPA [Member]
Derivative collateral required to be posted for ten-year PPA [Abstract]
Minimum collateral that may be required to be posted	20,000,000
Maximum collateral that may be required to be posted	40,000,000
Collateral posted	0
Ten-year PPA [Member] | Fuel For Electric Generation Purchased Power [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Realized losses (gains)	4,209,000	3,232,000
Ten-year PPA [Member] | Cost Of Gas Sold Expense [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Realized losses (gains)	$ 0	$ 0