Equity and Other Stock Related Information Equity and Other Stock Related Information (Details) - USD ($) $ / shares in Units, $ in Millions		12 Months Ended
		Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017	May 09, 2019
Subsidiary, Sale of Stock [Line Items]
Preferred Stock, Shares Outstanding		750,000
Preferred Stock, Value, Issued	[1]	$ 734	$ 0
Common Stock, Dividends, Per Share, Declared		$ 0.86	$ 0.72	$ 0.56
Dividends, Common Stock, Cash		$ 581	$ 534	$ 446
Preferred Stock, Value, Issued		$ 750
Treasury Stock, Shares, Acquired		106,000,000.0
Treasury Stock, Value, Acquired, Cost Method		$ 3,618	1,868	$ 1,497
Restricted Stock Units (RSUs)
Subsidiary, Sale of Stock [Line Items]
Conversion ratio to common stock		1
2014 Long-Term Incentive Plan [Member]
Subsidiary, Sale of Stock [Line Items]
Shares of common stock available for grant		43,600,000
Unrecognized compensation cost related to non-vested RSUs and Options		$ 99
Weighted average amortization period		2 years 3 months 18 days
2014 Long-Term Incentive Plan [Member] | Restricted Stock Units (RSUs)
Subsidiary, Sale of Stock [Line Items]
RSUs issued and outstanding (in shares)		5,100,000
2014 Long-Term Incentive Plan [Member] | Restricted Stock Units (RSUs) | Minimum
Subsidiary, Sale of Stock [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Period		3 years
2014 Long-Term Incentive Plan [Member] | Restricted Stock Units (RSUs) | Maximum
Subsidiary, Sale of Stock [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Period		5 years
2014 Long-Term Incentive Plan [Member] | Employee Stock Option
Subsidiary, Sale of Stock [Line Items]
Stock options issued and outstanding		7,100,000
Share Repurchase Program Through June 30, 2020 [Member]
Subsidiary, Sale of Stock [Line Items]
Stock Repurchase Program, Authorized Amount					$ 4,000
Series A Preferred Stock
Subsidiary, Sale of Stock [Line Items]
Preferred Stock, Dividend Rate, Percentage	[1]	5.625%
Preferred Stock, Redemption Price Per Share	[1]	$ 1,000
Preferred Stock, Shares Outstanding	[1]	750,000
Preferred Stock, Value, Issued	[1]	$ 734	$ 0
Preferred Stock, Value, Issued		$ 750

[1] Issued as depositary shares, each representing a 1/40th interest in a share of the corresponding series of non-cumulative perpetual preferred stock. Dividends are payable quarterly on February 15, May 15, August 15 and November 15 at a fixed rate, in each case when, as and if declared by the Board of Directors.