Income Taxes - Components of the deferred tax assets and liabilities (Details) - USD ($) $ in Millions	Dec. 31, 2022	Dec. 31, 2021
Deferred tax assets
Unearned premium reserves	$ 815	$ 742
Unrealized net capital losses	608	0
Discount on loss reserves	228	169
Research & development capitalization	219	0
Accrued compensation	128	151
Net operating loss carryover	97	88
Other postretirement benefits	15	31
Pension	10	0
Other assets	95	90
Total deferred tax assets before valuation allowance	2,215	1,271
Valuation allowance	(34)	(24)
Total deferred tax assets after valuation allowance	2,181	1,247
Deferred tax liabilities
DAC	(1,013)	(924)
Investments	(431)	(666)
Intangible assets	(147)	(219)
Unrealized net capital gains	0	(163)
Pension	0	(9)
Other liabilities	(204)	(99)
Total deferred tax liabilities	(1,795)	(2,080)
Net deferred tax assets (liabilities)	$ 386
Net deferred tax assets (liabilities)		$ (833)