Consolidated Statements of Shareholders' Equity (Parenthetical) - USD ($) $ in Millions		3 Months Ended		6 Months Ended	9 Months Ended	12 Months Ended
		Sep. 30, 2016	Mar. 31, 2016	Jun. 30, 2016	Dec. 31, 2016	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Treasury Stock, Value	[1]				$ (2,346)	$ (2,346)	$ (1,658)
Common stock dividends, per share		$ 0.26		$ 0.24		$ 1.00	$ 0.92	$ 0.70
Treasury Stock and Other
Treasury Stock, Value					(2,448)	$ (2,448)	$ (1,764)	$ (1,119)
Deferred Compensation Equity					(1)	(1)	(2)	(21)
Stockholders' Equity Attributable to Noncontrolling Interest					103	$ 103	$ 108	$ 108
Series A Preferred Stock [Member]
Preferred Stock, Dividends, Per Share, Cash Paid						$ 4,067	$ 4,056	$ 4,056
Series B Preferred Stock [Member]
Preferred Stock, Dividends, Per Share, Cash Paid						4,067	4,056	4,056
Series E Preferred Stock [Member]
Preferred Stock, Dividends, Per Share, Cash Paid						5,875	5,875	$ 5,875
Series F Preferred Stock [Member] | Additional Paid-in Capital [Member]
Preferred Stock, Dividends, Per Share, Cash Paid						$ 5,625	$ 6,219
Reclassifications from Additional paid in capital [Member] | Additional Paid-in Capital [Member]
Adjustment to Additional Paid in Capital, Income Tax Effect from Share-based Compensation, Net			$ (4)		$ (11)	$ (15)

[1] Includes noncontrolling interest of $103 million and $108 million at December 31, 2016 and December 31, 2015, respectively.