SHAREHOLDERS' EQUITY - Reclassifications Out of Accumulated Other Comprehensive Income (Details) - USD ($) $ in Millions		3 Months Ended						6 Months Ended
		Jun. 30, 2020		Mar. 31, 2020	Jun. 30, 2019		Mar. 31, 2019	Jun. 30, 2020		Jun. 30, 2019
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Net investment gains (losses)		$ 75			$ (25)			$ 145		$ (43)
Income tax (expense) or benefit		(265)			(292)			(419)		(606)
Net of tax		$ 805		$ 566	$ 817		$ 928	$ 1,370		$ 1,745
Blended statutory income tax rate		24.80%			26.30%			23.40%		25.80%
Reclassification Out Of Accumulated Other Comprehensive Income
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Net of tax		$ (61)			$ 16			$ (122)		$ 27
Reclassification Out Of Accumulated Other Comprehensive Income | Unrealized gains (losses) on available-for-sale securities
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Net investment gains (losses)		(75)			25			(145)		43
Income tax (expense) or benefit		19	[1]		(7)	[2]		34	[3]	(11)	[4]
Net of tax		(56)			18			(111)		32
Reclassification Out Of Accumulated Other Comprehensive Income | Pension liability adjustment
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Acquisition and operating expenses, actuarial gains (losses)	[5]	(7)			(3)			(15)		(7)
Acquisition and operating expenses, prior service (cost) credit	[5]	0			0			0		0
Income tax (expense) or benefit		2	[1]		1	[2]		4	[3]	2	[4]
Net of tax		$ (5)			$ (2)			$ (11)		$ (5)

[1] Based on 25% blended tax rate

[2] Based on 26% blended tax rate

[3] Based on 23% blended tax rate

[4] Based on 26% blended tax rate

[5] These accumulated other comprehensive income components are included in the computation of net periodic pension cost (see Note 12 for additional details).