Derivative Instruments (Change In Fair Value Of Derivative Instruments) (Details) - Other Income [Member] - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Not Designated as Hedging Instrument [Member] | Derivative Assets [Member]
Derivatives, Fair Value [Line Items]
Change in Fair Value	$ 2,244	$ 6,922	$ (15,846)	$ 4,494
Not Designated as Hedging Instrument [Member] | Derivative Liabilities [Member]
Derivatives, Fair Value [Line Items]
Change in Fair Value	(2,317)	(7,028)	16,181	(4,613)
Designated as Hedging Instrument [Member] | Derivative Assets [Member]
Derivatives, Fair Value [Line Items]
Change in Fair Value	(45)	101	119	89
Designated as Hedging Instrument [Member] | Derivative Liabilities [Member]
Derivatives, Fair Value [Line Items]
Change in Fair Value	$ 6	$ 5	$ 10	$ 6