Real Estate and Loans Receivable - Assets Acquired (Detail) - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Business Acquisition [Line Items]
Equity investments and other assets	$ 101,716	$ 33,708
Liabilities	(317)
Total assets acquired	2,218,869	767,696	$ 654,922
Loans repaid	(385,851)
Total net assets acquired	1,833,018	767,696	654,922
Land [Member]
Business Acquisition [Line Items]
Total assets acquired	126,336	22,569	41,473
Building [Member]
Business Acquisition [Line Items]
Total assets acquired	758,009	241,242	439,030
Intangible Lease Assets - Subject to Amortization [Member]
Business Acquisition [Line Items]
Total assets acquired	154,719	22,513	38,589
Net Investments in Direct Financing Leases [Member]
Business Acquisition [Line Items]
Total assets acquired	174,801		110,580
Other Loans [Member]
Business Acquisition [Line Items]
Total assets acquired	523,605	$ 447,664	5,250
Mortgage Loans [Member]
Business Acquisition [Line Items]
Total assets acquired	$ 380,000		$ 20,000