Real Estate and Loans Receivable - Assets Acquired (Detail) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Significant Acquisitions and Disposals [Line Items]
Total assets acquired	$ 654,922	$ 621,490	$ 293,555
Total liabilities assumed			(14,592)
Net assets acquired	654,922	621,490	278,963
Land [Member]
Significant Acquisitions and Disposals [Line Items]
Total assets acquired	41,473	518	19,705
Building [Member]
Significant Acquisitions and Disposals [Line Items]
Total assets acquired	439,030	8,942	220,769
Intangible lease assets - subject to amortization [Member]
Significant Acquisitions and Disposals [Line Items]
Total assets acquired	38,589	1,040	20,630
Net investments in direct financing leases [Member]
Significant Acquisitions and Disposals [Line Items]
Total assets acquired	110,580	310,000
Mortgage loans [Member]
Significant Acquisitions and Disposals [Line Items]
Total assets acquired	20,000	200,000
Working capital and other loans [Member]
Significant Acquisitions and Disposals [Line Items]
Total assets acquired	5,250	95,690	27,283
Equity investments [Member]
Significant Acquisitions and Disposals [Line Items]
Total assets acquired		$ 5,300	$ 5,168