CONSOLIDATED STATEMENTS OF STOCKHOLDERS' EQUITY - USD ($) $ in Millions	Total	Common Stock Member	Additional Paid In Capital Member	Retained Earnings Member	Treasury Stock, Common	Accumulated Other Comprehensive Income Member	Previously Reported	Previously Reported Common Stock Member	Previously Reported Additional Paid In Capital Member	Previously Reported Retained Earnings Member	Previously Reported Treasury Stock, Common	Previously Reported Accumulated Other Comprehensive Income Member
Total stockholders equity | Accounting Standards Update 2018-12	$ 6,839.0	$ 1.0	$ 2,406.0	$ 6,903.0	$ (1,562.0)	$ (909.0)	$ 14,352.0	$ 1.0	$ 2,406.0	$ 8,148.0	$ (1,562.0)	$ 5,359.0
Total stockholders equity | Effect of Modified Retrospective Application Accounting Standards Update 2018-12							(7,491.0)			(1,187.0)		(6,304.0)
Total stockholders equity | Effect of Retrospective Application of Accounting Standards Update 2018-12							(22.0)			$ (58.0)		$ 36.0
Stockholders' Equity Attributable to Noncontrolling Interest | Accounting Standards Update 2018-12	0.0						0.0
Stockholders' Equity, Including Portion Attributable to Noncontrolling Interest | Accounting Standards Update 2018-12	6,839.0						14,352.0
Stockholders' Equity, Including Portion Attributable to Noncontrolling Interest | Effect of Modified Retrospective Application Accounting Standards Update 2018-12							(7,491.0)
Stockholders' Equity, Including Portion Attributable to Noncontrolling Interest | Effect of Retrospective Application of Accounting Standards Update 2018-12							(22.0)
Net Income (Loss) Attributable to Parent	1,170.0
Other Comprehensive Income (Loss), Net of Tax	409.0					409.0
Other Comprehensive Income (Loss), Net of Tax | Accounting Standards Update 2018-12	$ 409.0						(1,717.0)
Common Stock, Dividends, Per Share, Declared	$ 2.86
Dividends, Common Stock, Cash	$ (194.0)			(194.0)
Purchase of treasury stock	(99.0)				99.0
Reissuance of treasury stock	(55.0)		(55.0)	(8.0)	(8.0)
Net income attributable to noncontrolling interest	0.0
Net Income	1,170.0
Net Income | Accounting Standards Update 2018-12	1,170.0						617.0
Total stockholders equity | Accounting Standards Update 2018-12	8,180.0	1.0	2,461.0	7,871.0	(1,653.0)	(500.0)	13,014.0
Stockholders' Equity Attributable to Noncontrolling Interest | Accounting Standards Update 2018-12	0.0						0.0
Stockholders' Equity, Including Portion Attributable to Noncontrolling Interest | Accounting Standards Update 2018-12	8,180.0						13,014.0
Net Income (Loss) Attributable to Parent	517.0
Other Comprehensive Income (Loss), Net of Tax	(1,371.0)					(1,371.0)
Other Comprehensive Income (Loss), Net of Tax | Accounting Standards Update 2018-12	$ (1,371.0)						(9,247.0)
Common Stock, Dividends, Per Share, Declared	$ 3.06
Dividends, Common Stock, Cash	$ (205.0)			(205.0)
Purchase of treasury stock	(81.0)				81.0
Reissuance of treasury stock	(41.0)		(41.0)	(14.0)	(14.0)
Noncontrolling Interest, Decrease from Distributions to Noncontrolling Interest Holders	(4.0)
Net income attributable to noncontrolling interest	4.0
Net Income	521.0
Net Income | Accounting Standards Update 2018-12	521.0						627.0
Total stockholders equity	7,081.0
Total stockholders equity | Accounting Standards Update 2018-12	7,081.0	1.0	2,502.0	8,169.0	(1,720.0)	(1,871.0)	4,145.0
Stockholders' Equity Attributable to Noncontrolling Interest	90.0
Stockholders' Equity Attributable to Noncontrolling Interest | Accounting Standards Update 2018-12	90.0						90.0
Stockholders' Equity, Including Portion Attributable to Noncontrolling Interest	7,171.0
Stockholders' Equity, Including Portion Attributable to Noncontrolling Interest | Accounting Standards Update 2018-12	7,171.0						$ 4,235.0
Net Income (Loss) Attributable to Parent	902.0			902.0
Other Comprehensive Income (Loss), Net of Tax	$ 1,502.0					1,502.0
Common Stock, Dividends, Per Share, Declared	$ 3.30
Dividends, Common Stock, Cash	$ (219.0)			(219.0)
Purchase of treasury stock	(227.0)				227.0
Reissuance of treasury stock	(42.0)		(42.0)	(47.0)	(47.0)
Noncontrolling Interest, Decrease from Distributions to Noncontrolling Interest Holders	(7.0)
Net income attributable to noncontrolling interest	7.0
Net Income	909.0
Net Income (Loss), Including Portion Attributable to Nonredeemable Noncontrolling Interest	909.0
Total stockholders equity	9,081.0	$ 1.0	$ 2,544.0	$ 8,805.0		$ (369.0)
Total stockholders equity | Accounting Standards Update 2018-12					$ (1,900.0)
Stockholders' Equity Attributable to Noncontrolling Interest	90.0
Stockholders' Equity, Including Portion Attributable to Noncontrolling Interest	$ 9,171.0