Segment And Geographic Information (Information Concerning Principal Geographic Areas) (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014
Revenues from External Customers and Long-Lived Assets [Line Items]
Total net revenue (loss)	$ 1,127	$ 1,231	$ 2,220	$ 2,373
Income (loss) from continuing operations before income tax expense	263	347	545	639
Net income (loss)	182	323	758	550
Foreign [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Total net revenue (loss)	28	33	53	66
Income (loss) from continuing operations before income tax expense	13	15	28	30
Net income (loss)	30	63	501	108
Canada [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Total net revenue (loss)	28	33	52	64
Income (loss) from continuing operations before income tax expense	13	16	24	29
Net income (loss)	13	36	21	46
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	0	(1)	4	1
Net income (loss)	17	1	28	4
Latin America [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	(7)	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	33	452	66
Domestic [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Total net revenue (loss)	1,099	1,198	2,167	2,307
Income (loss) from continuing operations before income tax expense	250	332	517	609
Net income (loss)	152	260	257	442
Amortization of Debt Discount (Premium)	$ 15	$ 50	$ 29	$ 98