Real Estate and Other Activities - Summary of Investments in Unconsolidated Operating Entities (Detail) - USD ($) $ in Thousands	Sep. 30, 2025	Dec. 31, 2024
Schedule of Equity Method Investments [Line Items]
Investments in unconsolidated operating entities	$ 319,192	$ 439,578
Swiss Medical Network [Member]
Schedule of Equity Method Investments [Line Items]
Investments in unconsolidated operating entities	196,537	172,453
Aevis Victoria SA [Member]
Schedule of Equity Method Investments [Line Items]
Investments in unconsolidated operating entities	62,858	63,409
Priory Group [Member]
Schedule of Equity Method Investments [Line Items]
Investments in unconsolidated operating entities	43,877	38,739
Aspris Children's Services [Member]
Schedule of Equity Method Investments [Line Items]
Investments in unconsolidated operating entities	15,920	15,950
PHP Holdings [Member]
Schedule of Equity Method Investments [Line Items]
Investments in unconsolidated operating entities	$ 0	$ 149,027