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, 2025 CAD ($)	Jun. 30, 2025 GBP (£)	Dec. 31, 2024 CAD ($)	Dec. 31, 2024 GBP (£)	Jun. 30, 2025 GBP (£)	Jun. 30, 2025 USD ($)	Dec. 31, 2024 GBP (£)	Dec. 31, 2024 USD ($)
Designated as Hedging Instrument | Denominated in Canadian Dollars | Net Investment Hedging
Derivatives, Fair Value [Line Items]
Derivative asset	$ 5,702,699		$ 2,904,028
Net investment hedges	250,000		250,000
Designated as Hedging Instrument | Denominated in Canadian Dollars | Cash Flow Hedging
Derivatives, Fair Value [Line Items]
Derivative asset	32,000		0
Designated as Hedging Instrument | Denominated in Pound Sterling | Net Investment Hedging
Derivatives, Fair Value [Line Items]
Derivative asset | £					£ 1,530,708		£ 1,430,708
Net investment hedges | £		£ 1,050,000		£ 1,050,000
Designated as Hedging Instrument | Denominated in U.S. Dollars | Cash Flow Hedging
Derivatives, Fair Value [Line Items]
Derivative asset						$ 0		$ 22,601
Designated as Hedging Instrument | Denominated in U.S. Dollars | Fair Value Hedging
Derivatives, Fair Value [Line Items]
Derivative asset						$ 550,000		$ 550,000
Derivative Instruments Not Designated | Denominated in Canadian Dollars
Derivatives, Fair Value [Line Items]
Derivative asset	$ 80,000		$ 80,000