Earnings (Loss) Per Common Share Level 4 (Details) - USD ($) $ / shares in Units, shares in Millions, $ in Millions	3 Months Ended			9 Months Ended
	Sep. 30, 2015	Dec. 31, 2014	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Net Income (Loss) Attributable to Parent [Abstract]
Income (Loss) from Continuing Operations Attributable to Parent	$ 372		$ 388	$ 1,252	$ 1,004
Income (Loss) from Discontinued Operations, Net of Tax, Including Portion Attributable to Noncontrolling Interest	9		0	9	(588)
Net Income (Loss) Attributable to Parent	$ 381		$ 388	$ 1,261	$ 416
Weighted Average Number of Shares Outstanding Reconciliation [Abstract]
Weighted Average Number of Shares Outstanding, Basic	413.8		437.2	418.4	445.9
Incremental Common Shares Attributable to Dilutive Effect of Call Options and Warrants	4.1		7.7	4.9	13.9
Incremental Common Shares Attributable to Dilutive Effect of Share-based Payment Arrangements	5.1		5.9	5.0	6.1
Weighted Average Number of Shares Outstanding, Diluted	423.0		450.8	428.3	465.9
Earnings Per Share, Basic and Diluted [Abstract]
Income (Loss) from Continuing Operations, Per Basic Share	$ 0.90		$ 0.89	$ 2.99	$ 2.25
Income (Loss) from Discontinued Operations and Disposal of Discontinued Operations, Net of Tax, Per Basic Share	0.02		0.00	0.02	(1.32)
Earnings Per Share, Basic	0.92		0.89	3.01	0.93
Income (Loss) from Continuing Operations, Per Diluted Share	0.88		0.86	2.92	2.15
Income (Loss) from Discontinued Operations and Disposal of Discontinued Operations, Net of Tax, Per Diluted Share	0.02		0.00	0.02	(1.26)
Earnings Per Share, Diluted	$ 0.90		$ 0.86	$ 2.94	$ 0.89
Accelerated Share Repurchase Program [Member]
Stock Repurchased During Period, Shares		3.5