Summary Of Significant Accounting Policies (Significant Unobservable Inputs in Asset Valuation) (Details)	Dec. 31, 2016	Dec. 31, 2015
Pilgrim [Member]
Weighted Average Cost Of Capital Used In Asset Valuation		7.90%
Operating Margin Used In Asset Valuation		8.10%
Pilgrim [Member] | Minimum [Member]
Weighted Average Cost Of Capital Used In Asset Valuation		7.50%
Operating Margin Used In Asset Valuation		2.40%
Pilgrim [Member] | Maximum [Member]
Weighted Average Cost Of Capital Used In Asset Valuation		8.00%
Operating Margin Used In Asset Valuation		10.60%
FitzPatrick [Member]
Weighted Average Cost Of Capital Used In Asset Valuation		7.50%
Operating Margin Used In Asset Valuation		10.20%
Palisades [Member]
Weighted Average Cost Of Capital Used In Asset Valuation	6.50%	7.50%
Operating Margin Used In Asset Valuation	34.60%	30.80%
Palisades [Member] | Minimum [Member]
Operating Margin Used In Asset Valuation	17.80%
Palisades [Member] | Maximum [Member]
Operating Margin Used In Asset Valuation	38.80%