Derivative and Hedging Instruments (Details-5) (USD $)			3 Months Ended		6 Months Ended		3 Months Ended		6 Months Ended		3 Months Ended		6 Months Ended		3 Months Ended		6 Months Ended			3 Months Ended		6 Months Ended		3 Months Ended		6 Months Ended
	Jun. 30, 2014 counterparty	Dec. 31, 2013 counterparty	Jun. 30, 2014 Commodity Derivative Contracts [Member] Fuel For Electric Generation Purchased Power [Member]	Jun. 30, 2013 Commodity Derivative Contracts [Member] Fuel For Electric Generation Purchased Power [Member]	Jun. 30, 2014 Commodity Derivative Contracts [Member] Fuel For Electric Generation Purchased Power [Member]	Jun. 30, 2013 Commodity Derivative Contracts [Member] Fuel For Electric Generation Purchased Power [Member]	Jun. 30, 2014 Commodity Derivative Contracts [Member] Cost Of Gas Sold Expense [Member]	Jun. 30, 2013 Commodity Derivative Contracts [Member] Cost Of Gas Sold Expense [Member]	Jun. 30, 2014 Commodity Derivative Contracts [Member] Cost Of Gas Sold Expense [Member]	Jun. 30, 2013 Commodity Derivative Contracts [Member] Cost Of Gas Sold Expense [Member]	Jun. 30, 2014 Financial Transmission Rights [Member] Fuel For Electric Generation Purchased Power [Member]	Jun. 30, 2013 Financial Transmission Rights [Member] Fuel For Electric Generation Purchased Power [Member]	Jun. 30, 2014 Financial Transmission Rights [Member] Fuel For Electric Generation Purchased Power [Member]	Jun. 30, 2013 Financial Transmission Rights [Member] Fuel For Electric Generation Purchased Power [Member]	Jun. 30, 2014 Financial Transmission Rights [Member] Cost Of Gas Sold Expense [Member]	Jun. 30, 2013 Financial Transmission Rights [Member] Cost Of Gas Sold Expense [Member]	Jun. 30, 2014 Financial Transmission Rights [Member] Cost Of Gas Sold Expense [Member]	Jun. 30, 2013 Financial Transmission Rights [Member] Cost Of Gas Sold Expense [Member]	Jun. 30, 2014 Purchased Power Agreement [Member]	Jun. 30, 2014 Purchased Power Agreement [Member] Fuel For Electric Generation Purchased Power [Member]	Jun. 30, 2013 Purchased Power Agreement [Member] Fuel For Electric Generation Purchased Power [Member]	Jun. 30, 2014 Purchased Power Agreement [Member] Fuel For Electric Generation Purchased Power [Member]	Jun. 30, 2013 Purchased Power Agreement [Member] Fuel For Electric Generation Purchased Power [Member]	Jun. 30, 2014 Purchased Power Agreement [Member] Cost Of Gas Sold Expense [Member]	Jun. 30, 2013 Purchased Power Agreement [Member] Cost Of Gas Sold Expense [Member]	Jun. 30, 2014 Purchased Power Agreement [Member] Cost Of Gas Sold Expense [Member]	Jun. 30, 2013 Purchased Power Agreement [Member] Cost Of Gas Sold Expense [Member]
Realized losses (gains) on income statement [Line Items]
Realized losses (gains) on income statement			$ (1,061,000)	$ (538,000)	$ (5,856,000)	$ (516,000)	$ (128,000)	$ 0	$ (1,349,000)	$ 608,000	$ (196,000)	$ (351,000)	$ (832,000)	$ (509,000)	$ 0	$ 0	$ 0	$ 0		$ 602,000	$ 1,075,000	$ (607,000)	$ 2,353,000	$ 0	$ 0	$ 0	$ 0
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
Counterparties in net liability position or default [Abstract]
Counterparties in net liability position	0	0
Number of counterparties in default	0