Segment And Geographic Information (Information Concerning Principal Geographic Areas) (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended								12 Months Ended
	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Revenues from External Customers and Long-Lived Assets [Line Items]
Total net revenue (loss)	$ 1,014	$ 1,264	$ 1,231	$ 1,142	$ 1,099	$ 1,108	$ 1,030	$ 1,026	$ 4,651	$ 4,263	$ 4,465
Income (loss) from continuing operations before income tax expense	187	420	347	292	75	205	140	(63)	1,246	357	514
Net income (loss)	177	423	323	227	104	91	(927)	1,093	1,150	361	1,196
Identifiable Assets	151,801				151,140				151,801	151,140	182,320
Long-Lived Assets	19,735				17,916				19,735	17,916	13,881
Foreign [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Total net revenue (loss)									126	164	211
Income (loss) from continuing operations before income tax expense									54	51	18
Net income (loss)									186	1,595	796
Identifiable Assets	2,891				3,225				2,891	3,225	32,778
Long-Lived Assets	0				0				0	0	50
Canada [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Total net revenue (loss)									124	171	233
Income (loss) from continuing operations before income tax expense									54	64	48
Net income (loss)									68	1,266	295
Identifiable Assets	590				704				590	704	13,362
Long-Lived Assets	0				0				0	0	1
Europe [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Total net revenue (loss)									2	(8)	(28)
Income (loss) from continuing operations before income tax expense									0	(18)	(14)
Net income (loss)									4	(88)	183
Identifiable Assets	1,636				1,972				1,636	1,972	10,971
Long-Lived Assets	0				0				0	0	16
Latin America [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Total net revenue (loss)									0	0	2
Income (loss) from continuing operations before income tax expense									0	7	(19)
Net income (loss)									(8)	300	219
Identifiable Assets	29				29				29	29	8,050
Long-Lived Assets	0				0				0	0	33
Asia-Pacific [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Total net revenue (loss)									0	1	4
Income (loss) from continuing operations before income tax expense									0	(2)	3
Net income (loss)									122	117	99
Identifiable Assets	636				520				636	520	395
Long-Lived Assets	0				0				0	0	0
Domestic [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Total net revenue (loss)									4,525	4,099	4,254
Income (loss) from continuing operations before income tax expense									1,192	306	496
Net income (loss)									964	(1,234)	400
Identifiable Assets	148,910				147,915				148,910	147,915	149,542
Long-Lived Assets	19,735				17,916				19,735	17,916	13,831
Amortization of Debt Discount (Premium)									$ 189	$ 262	$ 349