Real Estate and Lending Activities - Assets Acquired (Detail) - USD ($) $ in Thousands		Sep. 30, 2017	Sep. 30, 2016
Business Acquisition [Line Items]
Total assets acquired		$ 2,152,069	$ 213,100
Equity investments		100,000
Liabilities assumed		(878)
Loans repaid	[1]		(93,262)
Total net assets acquired		2,152,069	119,838
Land and Land Improvements [Member]
Business Acquisition [Line Items]
Total assets acquired		196,094	13,602
Building [Member]
Business Acquisition [Line Items]
Total assets acquired		987,442	125,744
Intangible Lease Assets - Subject to Amortization [Member]
Business Acquisition [Line Items]
Total assets acquired		128,961	10,754
Net Investments in Direct Financing Leases [Member]
Business Acquisition [Line Items]
Total assets acquired		40,450	$ 63,000
Mortgage Loans [Member]
Business Acquisition [Line Items]
Total assets acquired		$ 700,000

[1] $93.3 million loans advanced to Capella (now RCCH Healthcare Partners ("RCCH")) in 2015 and repaid in 2016 as a part of the Capella Transaction.