Excess of issue price over par or stated value of the entity's capital stock and amounts received from other transactions involving the entity's stock or stockholders. Includes adjustments to additional paid in capital. Some examples of such adjustments include recording the issuance of debt with a beneficial conversion feature and certain tax consequences of equity instruments awarded to employees. Use this element for the aggregate amount of additional paid-in capital associated with common and preferred stock. For additional paid-in capital associated with only common stock, use the element additional paid in capital, common stock. For additional paid-in capital associated with only preferred stock, use the element additional paid in capital, preferred stock.

Name:	us-gaap_AdditionalPaidInCapital
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

Statement - USD ($) shares in Thousands, $ in Millions	3 Months Ended		6 Months Ended
Statement - USD ($) shares in Thousands, $ in Millions	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018	Mar. 31, 2019	Dec. 31, 2018	Mar. 31, 2018	Dec. 31, 2017
Stockholders' Equity	$ 7,599		$ 7,599			$ 7,578
Common stock, outstanding shares	176,935		176,935			187,554
Additional Paid-in Capital	$ 3,271		$ 3,271			$ 3,806
Net Income (Loss), Including Portion Attributable to Noncontrolling Interest	198	$ 197	411	$ 435
Other comprehensive income (loss)	$ 148	$ (49)	$ 275	$ (176)
Stock Repurchased During Period, Shares	5,800	4,300	11,300
Common Stock, Dividends, Per Share, Declared			$ 0.60	$ 0.44
Preferred Stock [Member]
Stockholders' Equity	$ 566	$ 566	$ 566	$ 566	$ 566	566	$ 566	$ 566
Common Stock [Member]
Stockholders' Equity	$ 0	$ 4,231	$ 0	$ 4,231	$ 0	$ 0	$ 4,346	$ 4,445
Common stock, outstanding shares	176,935	195,392	176,935	195,392	182,513	187,554	197,050	197,532
Stock Repurchased During Period, Shares	5,857	2,270	11,363	4,541
Stock Repurchased During Period, Value		$ (127)		$ (248)
Net Shares Issued From Stock Warrant Exercises	7	53	8	1,095
Stock Issued During Period, Shares, Restricted Stock Award, Net of Forfeitures	272	559	736	1,306
Stock Issued During Period, Value, Restricted Stock Award, Net of Forfeitures		$ 12		$ 34
Additional Paid-in Capital [Member]
Additional Paid-in Capital	$ 3,271	0	$ 3,271	0	$ 3,541	$ 3,806	$ 0	$ 0
Stock Repurchased During Period, Value	(276)		(551)
Employee Plans, Accumulated Paid-in Capital	6		16
Retained Earnings [Member]
Cumulative Effect of ASU 2017-08			(3)
Stockholders' Equity	3,737	3,139	3,737	3,139	3,603	3,456	2,999	2,807
Net Income (Loss), Including Portion Attributable to Noncontrolling Interest	198	197	411	435
New Accounting Pronouncement or Change in Accounting Principle, Effect of Adoption, Quantification				1
Dividends, Preferred Stock	10	10	17	17
Dividends, Common Stock	(54)	(47)	(110)	(87)
Accumulated Other Comprehensive Income (Loss) [Member]
Stockholders' Equity	25	(315)	25	(315)	122	(250)	267	(139)
Other comprehensive income (loss)	147	(48)	275	(176)
Parent [Member]
Cumulative Effect of ASU 2017-08			(3)
Stockholders' Equity	7,599	7,621	7,599	7,621	$ 7,588	$ 7,578	$ 7,644	$ 7,679
Net Income (Loss), Including Portion Attributable to Noncontrolling Interest	198	197	411	435
Other comprehensive income (loss)	147	(48)	275	(176)
New Accounting Pronouncement or Change in Accounting Principle, Effect of Adoption, Quantification				1
Stock Repurchased During Period, Value	(276)	(127)	(551)	(248)
Employee Plans, Accumulated Paid-in Capital	6	12	16
Stock Issued During Period, Value, Restricted Stock Award, Net of Forfeitures				34
Dividends, Preferred Stock	10	10	17	17
Dividends, Common Stock	$ (54)	$ (47)	$ (110)	$ (87)