Derivative Instruments - Summary of Notional Amount of Derivatives and Other Financial Instruments (Details) £ in Thousands, $ in Thousands, $ in Thousands	6 Months Ended		12 Months Ended
	Jun. 30, 2026 CAD ($)	Jun. 30, 2026 GBP (£)	Dec. 31, 2025 CAD ($)	Dec. 31, 2025 GBP (£)	Jun. 30, 2026 GBP (£)	Jun. 30, 2026 USD ($)	Dec. 31, 2025 GBP (£)	Dec. 31, 2025 USD ($)
Denominated in Canadian Dollars \| Derivative Instruments Not Designated
Derivatives, Fair Value [Line Items]
Derivative asset	$ 2,827,565		$ 2,827,565
Denominated in Canadian Dollars \| Net Investment Hedging \| Designated as Hedging Instrument
Derivatives, Fair Value [Line Items]
Derivative asset	7,051,059		5,702,699
Net investment hedges	0		250,000
Denominated in Canadian Dollars \| Cash Flow Hedging \| Designated as Hedging Instrument
Derivatives, Fair Value [Line Items]
Derivative asset	$ 74,188		$ 32,000
Denominated in Pounds Sterling \| Net Investment Hedging \| Designated as Hedging Instrument
Derivatives, Fair Value [Line Items]
Derivative asset \| £					£ 8,850,708		£ 8,830,708
Net investment hedges \| £		£ 0		£ 1,050,000
Denominated in Pounds Sterling \| Fair Value Hedging \| Designated as Hedging Instrument
Derivatives, Fair Value [Line Items]
Derivative asset \| £					£ 1,050,000		£ 0
Denominated in U.S. Dollars \| Fair Value Hedging \| Designated as Hedging Instrument
Derivatives, Fair Value [Line Items]
Derivative asset						$ 550,000		$ 550,000