Segments of Operations - Earnings before income taxes by segment and sub-segment (Details) - USD ($) $ in Millions		3 Months Ended			6 Months Ended
		Jun. 30, 2020		Jun. 30, 2019	Jun. 30, 2020		Jun. 30, 2019
Segment Reporting Information [Line Items]
Earnings before realized gains (losses) and income taxes		$ 14		$ 203	$ 177		$ 432
Realized gains (losses) on securities		204		56	(347)		240
Earnings (loss) before income taxes		218		259	(170)		672
Property and Casualty Insurance
Segment Reporting Information [Line Items]
Property and casualty insurance underwriting		9		59	96		146
Investment and other income, net		65	[1]	115	149	[1]	210
Earnings before realized gains (losses) and income taxes		74		174	245		356
Annuity
Segment Reporting Information [Line Items]
Earnings before realized gains (losses) and income taxes		(17)		71	12		161
Other
Segment Reporting Information [Line Items]
Earnings before realized gains (losses) and income taxes	[2]	(43)		(42)	(80)		(85)
Specialty Property and transportation | Property and Casualty Insurance
Segment Reporting Information [Line Items]
Property and casualty insurance underwriting		33		4	60		43
Specialty casualty | Property and Casualty Insurance
Segment Reporting Information [Line Items]
Property and casualty insurance underwriting		27		47	79		83
Specialty financial | Property and Casualty Insurance
Segment Reporting Information [Line Items]
Property and casualty insurance underwriting		0		21	17		34
Other specialty | Property and Casualty Insurance
Segment Reporting Information [Line Items]
Property and casualty insurance underwriting		(6)		(12)	(13)		(12)
Other lines | Property and Casualty Insurance
Segment Reporting Information [Line Items]
Property and casualty insurance underwriting	[3]	$ (45)		$ (1)	$ (47)		$ (2)

[1] Includes $1 million and $10 million in the second quarter and first six months of 2020, respectively, in net expenses from the Neon exited lines, before noncontrolling interest.

[2] Includes holding company interest and expenses.

[3] Includes an underwriting loss of $43 million in the second quarter of 2020 and $44 million in the first six months of 2020 in the Neon exited lines. Neon’s $4 million and $14 million underwriting losses in the second quarter and first six months of 2019, respectively, are included in the Specialty casualty sub-segment.