Summary of Significant Accounting Policies (Detail Textuals 1) (USD $)	6 Months Ended
	Jun. 30, 2013
Significant Accounting Policies [Line Items]
Electric inputs weighted average price per megawatt-hour	37.30
Minimum
Significant Accounting Policies [Line Items]
Electric inputs price per megawatt-hour	18.00
Maximum
Significant Accounting Policies [Line Items]
Electric inputs price per megawatt-hour	50.00
Forward Electricity Contracts | Power purchase contracts | Level 3
Significant Accounting Policies [Line Items]
Derivative asset	$ 436,000
Derivative liability	12,591,000
Percentage of offset by regulatory liabilities and assets of fuel clause adjustment treatment of fuel costs	100.00%
Net impact of recorded fair valuation gains or losses related to derivative contract	0
Net income impact of future fair valuation adjustments of contracts	0
Forward Electricity Contracts | Financial contracts | Level 3
Significant Accounting Policies [Line Items]
Derivative asset	744,000
Derivative liability	$ 703,000
Percentage of offset by regulatory liabilities and assets of fuel clause adjustment treatment of fuel costs	100.00%