Commitments, Contingencies and Guarantees (Guarantees Issued) (Details) - USD ($) $ in Millions	Jun. 30, 2022	Dec. 31, 2021
Treaty guarantees
Guarantor Obligations [Line Items]
Guarantor Obligations, Current Carrying Value	$ 1,946	$ 2,208
Treaty guarantees, net of assets in trust
Guarantor Obligations [Line Items]
Guarantor Obligations, Current Carrying Value	1,139	1,281
Securities borrowing and repurchase arrangements
Guarantor Obligations [Line Items]
Guarantor Obligations, Current Carrying Value	$ 170	$ 134

The current carrying amount of the liability for the freestanding or embedded guarantor's obligations under the guarantee or each group of similar guarantees.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 460
-SubTopic 10
-Section 50
-Paragraph 4
-Subparagraph (c)
-URI http://asc.fasb.org/extlink&oid=124440162&loc=d3e12069-110248

Name:	us-gaap_GuaranteeObligationsCurrentCarryingValue
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant