Real Estate Activities - Assets Acquired (Detail) - USD ($) $ in Thousands		Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Business Acquisition [Line Items]
Equity investments and other assets		$ 415,836	$ 245,267	$ 100,000
Liabilities assumed		(2,637)		(878)
Total assets acquired		4,565,594	1,430,995	2,246,788
Loans repaid	[1]		(764,447)
Total net assets acquired		4,565,594	666,548	2,246,788
Land [Member]
Business Acquisition [Line Items]
Total assets acquired		400,539	71,880	240,993
Building [Member]
Business Acquisition [Line Items]
Total assets acquired		1,951,066	686,739	985,219
Intangible Lease Assets - Subject to Amortization [Member]
Business Acquisition [Line Items]
Total assets acquired		227,468	90,651	181,004
Investment in Financing Leases [Member]
Business Acquisition [Line Items]
Total assets acquired		1,386,797		40,450
Other Loans [Member]
Business Acquisition [Line Items]
Total assets acquired		135,258	$ 336,458
Mortgage Loans [Member]
Business Acquisition [Line Items]
Total assets acquired		$ 51,267		$ 700,000

[1] The 2018 column includes $0.8 billion of loans advanced to Steward in 2016 and repaid in 2018 as part of sale leaseback conversion described below.