Segment And Geographic Information (Information Concerning Principal Geographic Areas) (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Revenues from External Customers and Long-Lived Assets [Line Items]
Total net revenue (loss)	$ 1,302	$ 1,264	$ 3,522	$ 3,637
Income (loss) from continuing operations before income tax expense	417	420	962	1,059
Net income (loss)	268	423	1,026	973
Foreign [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Total net revenue (loss)	24	31	77	97
Income (loss) from continuing operations before income tax expense	12	6	40	36
Net income (loss)	9	39	510	147
Canada [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Total net revenue (loss)	24	31	76	95
Income (loss) from continuing operations before income tax expense	11	7	35	36
Net income (loss)	9	9	30	55
Europe [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Total net revenue (loss)	0	0	1	2
Income (loss) from continuing operations before income tax expense	1	(1)	5	0
Net income (loss)	0	1	28	5
Latin America [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Total net revenue (loss)			0	0
Income (loss) from continuing operations before income tax expense			0	0
Net income (loss)			0	(8)
Asia-Pacific [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Total net revenue (loss)	0	0	0	0
Income (loss) from continuing operations before income tax expense	0	0	0	0
Net income (loss)	0	29	452	95
Domestic [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Total net revenue (loss)	1,278	1,233	3,445	3,540
Income (loss) from continuing operations before income tax expense	405	414	922	1,023
Net income (loss)	259	384	516	826
Amortization of Debt Discount (Premium)	$ 16	$ 51	$ 45	$ 149