Summary Of Significant Accounting Policies (Narrative) (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2015 USD ($) years	Dec. 31, 2014 USD ($)	Dec. 31, 2013 USD ($)	Jun. 30, 2014
Summary Of Significant Accounting Policies [Line Items]
Unamortized Debt Issuance Expense	$ 10,852	$ 11,360
Purchase accounting adjustments	$ (304)	112
Period of time receiving power, years | years	32.5
Unrecognized Tax Benefits, Income Tax Penalties and Interest Expense	$ 0	$ 0	$ 0
Ecova [Member]
Summary Of Significant Accounting Policies [Line Items]
Owners percentage interest				80.20%
Minimum [Member]
Summary Of Significant Accounting Policies [Line Items]
Lessee Leasing Arrangements, Operating Leases, Term of Contract	1 year
Maximum [Member]
Summary Of Significant Accounting Policies [Line Items]
Lessee Leasing Arrangements, Operating Leases, Term of Contract	45 years