Reclassification From Accumulated Other Comprehensive Income (Components Of Accumulated Other Comprehensive Income (Loss)) (Details) $ in Millions	9 Months Ended
	Sep. 30, 2015 USD ($)
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning balance at December 31, 2014	$ 62
Other comprehensive income (loss) before reclassifications	12
Amounts reclassified from/to other comprehensive income (loss)	(87)
Net current-period other comprehensive income (loss)	(75)
Ending balance at September 30, 2015	(13)
Cash Flow Hedges [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning balance at December 31, 2014	98
Other comprehensive income (loss) before reclassifications	21
Amounts reclassified from/to other comprehensive income (loss)	(88)
Net current-period other comprehensive income (loss)	(67)
Ending balance at September 30, 2015	31
Pension And Other Postretirement [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning balance at December 31, 2014	$ (24)
Other comprehensive income (loss) before reclassifications
Amounts reclassified from/to other comprehensive income (loss)	$ 1
Net current-period other comprehensive income (loss)	1
Ending balance at September 30, 2015	(23)
Foreign Currency [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning balance at December 31, 2014	(12)
Other comprehensive income (loss) before reclassifications	$ (9)
Amounts reclassified from/to other comprehensive income (loss)
Net current-period other comprehensive income (loss)	$ (9)
Ending balance at September 30, 2015	$ (21)