Aggregate Estimated Fair Value of Assets and Liabilities Acquired (Detail) (Series of Individually Immaterial Business Acquisitions, USD $) In Thousands, unless otherwise specified	Sep. 30, 2014
Series of Individually Immaterial Business Acquisitions
Assets acquired:
Investments in real estate	$ 418,427
Cash and cash equivalents	308
Restricted cash	3,094
Other assets	2,590
Deferred financing costs	993
Intangible assets	8,767
Total assets acquired	434,179
Liabilities assumed:
Loans payable on real estate	127,755
Accounts payable and accrued expenses	5,480
Other liabilities	710
Total liabilities assumed	133,945
Noncontrolling interests assumed:	3,000
Estimated fair value of net assets acquired	$ 297,234