Commitments, contingencies, and guarantees (Tables)

12 Months Ended

Dec. 31, 2024

Commitments and Contingencies Disclosure [Abstract]

Balance Sheet Locations, Fair Values In An Asset Or (Liability) Position, And Notional Values/Payment Provisions Of Derivative Instruments

The following table presents the balance sheet location, fair value in an asset or (liability) position, and notional value/payment provision of our derivative instruments:

		December 31, 2024						December 31, 2023
	Consolidated Balance Sheet Location	Fair Value				Notional Value/ Payment Provision		Fair Value				Notional Value/ Payment Provision
		Derivative Asset		Derivative (Liability)				Derivative Asset		Derivative (Liability)
(in millions of U.S. dollars)
Investment and embedded derivatives not designated as hedging instruments:
Foreign currency forward contracts	OA / (AP)	$	41	$	(295)	$	3,959	$	27	$	(94)	$	3,662
Options/Futures contracts on notes and bonds	OA / (AP)	—		(8)		449		27		(42)		2,062
Convertible securities (1)	FM AFS / ES	12		—		12		56		—		64
Total		$	53	$	(303)	$	4,420	$	110	$	(136)	$	5,788
Other derivative instruments:
Futures contracts on equities (2)	OA / (AP)	$	35	$	—	$	1,047	$	—	$	(37)	$	1,157
Other	OA / (AP)	—		(2)		211		—		(5)		217
Total		$	35	$	(2)	$	1,258	$	—	$	(42)	$	1,374
Derivatives designated as hedging instruments:
Cross-currency swaps - fair value hedges	OA / (AP)	$	103	$	—	$	1,579	$	126	$	—	$	1,631
Cross-currency swaps - net investment hedges	OA / (AP)	43		(116)		2,896		10		(128)		1,619
Total		$	146	$	(116)	$	4,475	$	136	$	(128)	$	3,250

(1)Includes fair value of embedded derivatives.

(2)Related to MRB book of business.

Schedule of Fair Value Hedging Instruments, Statements of Financial Performance and Financial Position, Location

	Year Ended December 31
(pre-tax, in millions of U.S. dollars)	2024		2023
Gain (loss) recognized in OCI	$	(38)	$	101
Net realized gain (loss) reclassified from OCI	(103)		50
Interest expense reclassified from OCI	(15)		(16)
OCI gain (loss) after reclassifications	$	80	$	67

Schedule of Net Investment Hedges, Statements of Financial Performance and Financial Position, Location

	Year Ended December 31
(pre-tax, in millions of U.S. dollars)	2024		2023
Gain (loss) recognized in OCI	$	58	$	(58)
Interest income reclassified from OCI	19		13
OCI gain (loss) after reclassifications	$	39	$	(71)

Derivative Instruments, Gain (Loss) [Table Text Block]

The following table presents net gains (losses) related to derivative instrument activity in the Consolidated statements of operations:

	Year Ended December 31
(in millions of U.S. dollars)	2024		2023		2022
Investment and embedded derivative instruments:
Foreign currency forward contracts	$	(213)	$	(50)	$	(339)
Options/Futures contracts on notes and bonds	22		(2)		297
Convertible securities (1)	2		(1)		(1)
Total investment and embedded derivative instruments	$	(189)	$	(53)	$	(43)
Other derivative instruments:
Futures contracts on equities (2)	(165)		(189)		187
Other	(4)		(10)		(11)
Total other derivative instruments	$	(169)	$	(199)	$	176
Total	$	(358)	$	(252)	$	133

(1)Includes embedded derivatives.

(2)Related to MRB book of business.

Secured Borrowings Securities Lending Table

The following table presents the carrying value of collateral held under securities lending agreements by investment category and remaining contractual maturity of the underlying agreements:

	Remaining contractual maturity
	December 31, 2024		December 31, 2023
(in millions of U.S. dollars)	Overnight and Continuous
Collateral held under securities lending agreements:
Cash	$	557	$	555
U.S. Treasury / Agency	145		33
Non-U.S.	663		621
Corporate and asset-backed securities	49		57
Municipal	3		6
Equity securities	28		27
Total	$	1,445	$	1,299
Gross amount of recognized liability for securities lending payable	$	1,445	$	1,299

The following table presents the carrying value of collateral pledged under repurchase agreements by investment category and remaining contractual maturity of the underlying agreements:

			Remaining contractual maturity
	December 31, 2024										December 31, 2023
	Up to 30 Days		30-90 Days		Greater than 90 Days				Up to 30 Days		30-90 Days		Greater than 90 Days		Total
(in millions of U.S. dollars)							Total
Collateral pledged under repurchase agreements:
Cash	$	—	$	19	$	2	$	21	$	—	$	33	$	1	$	34
Non-U.S.	1,387		—		—		1,387		1,355		—		—		1,355
U.S. Treasury / Agency	—		—		104		104		—		105		—		105
Mortgage-backed securities	—		454		924		1,378		—		913		517		1,430
Total	$	1,387	$	473	$	1,030	$	2,890	$	1,355	$	1,051	$	518	$	2,924
Gross amount of recognized liabilities for repurchase agreements							$	2,731							$	2,833
Difference (1)							$	159							$	91

(1)Per the repurchase agreements, the amount of collateral posted is required to exceed the amount of gross liability.

Lessee, Operating Lease, Liability, Maturity

Future minimum lease payments under the operating leases are expected to be as follows:

For the years ending December 31
(in millions of U.S. dollars)
Undiscounted cash flows:
2025	$	178
2026	154
2027	117
2028	90
2029	74
Thereafter	759
Total undiscounted lease payments	$	1,372
Less: Present value adjustment	430
Net lease liabilities reported as of December 31, 2024	$	942