Reinsurance - Summary of long-term insurance (Details) - USD ($) $ in Millions	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Long-Duration Insurance
Effects of Reinsurance [Line Items]
Long-duration insurance in force ceded	$ 346,879	$ 363,008	$ 349,453

Amount of life insurance issued and outstanding ceded to other entity, as disclosed in supplementary reinsurance information. Includes, but is not limited to, dividend and adjustment to face value.

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher SEC
-Name Regulation S-X (SX)
-Number 210
-Section 12
-Paragraph Column C
-Subsection 17

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 944
-SubTopic 235
-Section S99
-Paragraph 2
-Subparagraph (SX 210.12-17(Column C))
-URI https://asc.fasb.org/extlink&oid=120401096&loc=d3e574992-122915

Name:	srt_LifeInsuranceInForceCeded
Namespace Prefix:	srt_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant