Schedule IV - Changes in Mortgage Loans Excluding Allowance for Credit Loss (Parenthetical) (Detail) $ in Thousands, £ in Millions			12 Months Ended
		May 23, 2023 USD ($)	Dec. 31, 2023 USD ($)	Dec. 31, 2023 GBP (£)	Dec. 31, 2021 USD ($)	Mar. 31, 2021 GBP (£)
Mortgage Loans on Real Estate [Line Items]
Advanced to the mortgage loan	[1]		$ 22,900		$ 1,103,410
PHP Holdings [Member] | Prospect Medical Holdings Inc [Member]
Mortgage Loans on Real Estate [Line Items]
Unpaid rent and interest		$ 112,900
Mortgage Loans [Member] | PHP Holdings [Member] | Prospect Medical Holdings Inc [Member]
Mortgage Loans on Real Estate [Line Items]
Unpaid rent and interest		$ 151,000	$ 151,000
Mortgage Loans [Member] | Priory Group [Member]
Mortgage Loans on Real Estate [Line Items]
Advanced to the mortgage loan | £				£ 23		£ 800

[1] The 2023 column includes a $23 million mortgage loan that was converted to fee simple ownership of one property as described under the Lifepoint Transaction below. The 2021 column includes an £800 million mortgage loan advanced to the Priory Group (“Priory”) in the first quarter of 2021 and converted to fee simple ownership of 35 properties in the second quarter of 2021 as described below.