Reclassification From Accumulated Other Comprehensive Income (Components Of Accumulated Other Comprehensive Income (Loss)) (Details) $ in Millions	6 Months Ended
	Jun. 30, 2015 USD ($)
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning balance at December 31, 2014	$ 62
Other comprehensive income (loss) before reclassifications	9
Amounts reclassified from other comprehensive income (loss)	(58)
Net current-period other comprehensive loss	(49)
Ending balance at June 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	13
Amounts reclassified from other comprehensive income (loss)	(58)
Net current-period other comprehensive loss	(45)
Ending balance at June 30, 2015	53
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 other comprehensive income (loss)
Net current-period other comprehensive loss
Ending balance at June 30, 2015	$ (24)
Foreign Currency [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning balance at December 31, 2014	(12)
Other comprehensive income (loss) before reclassifications	$ (4)
Amounts reclassified from other comprehensive income (loss)
Net current-period other comprehensive loss	$ (4)
Ending balance at June 30, 2015	$ (16)