Commitments and Contingencies (Details) - USD ($)	Sep. 30, 2015	Jun. 15, 2015
Long-term Purchase Commitment [Line Items]
Contract Amount		$ 170,300,000
New Source Review [Member]
Long-term Purchase Commitment [Line Items]
Potential Penalty Under the Federal Clean Air Act	$ 37,500
Clean Power Plan [Member]
Long-term Purchase Commitment [Line Items]
Proposed Rate-Based Carbon Reduction	43.00%
Final Rate-Based Carbon Reduction	32.00%
Mass-Based Carbon Reduction	24.00%