Significant Accounting Policies (Narrative) (Details) (USD $)	Jun. 30, 2014	Dec. 31, 2013
Significant Accounting Policies [Line Items]
Accounts receivable	$ 42,668,493	$ 44,633,981
Fuel stock	9,115,224	13,029,848
Marketable securities	10,532,187	10,308,533
Fair Value [Member]
Significant Accounting Policies [Line Items]
Marketable securities	10,500,000	10,300,000
ML&P For Fuel and South Central Power Project Costs [Member]
Significant Accounting Policies [Line Items]
Accounts receivable	1,400,000	1,800,000
Alaska Energy Authority For Grant [Member]
Significant Accounting Policies [Line Items]
Accounts receivable	$ 600,000	$ 2,800,000