Real Estate and Other Activities - Other Investment Activities - Additional Information (Detail) £ in Millions, SFr in Millions, $ in Millions	3 Months Ended		6 Months Ended
	Mar. 31, 2024 USD ($)	Mar. 31, 2024 GBP (£)	Jun. 30, 2023 CHF (SFr)
Syndicated Term Loan [Member]
Business Acquisition [Line Items]
Gain (loss) on sale of interest in syndicated term loan	$ (7.8)	£ (6)
Proceed from sale of interest in syndicated term loan	$ 115.0	£ 90
Steward Health Care System LLC [Member]
Business Acquisition [Line Items]
Repayments of mortgage loan			SFr 60