Summary of Aggregate Consideration and Preliminary Fair Value of Assets Acquired and Liabilities Assumed Recognized at Acquisition Date (Detail) (USD $) In Thousands, unless otherwise specified				3 Months Ended
	Mar. 31, 2014	Dec. 31, 2013		Mar. 31, 2014 CreXus	Mar. 31, 2014 CreXus Commercial real estate investments	Mar. 31, 2014 CreXus Accrued interest receivable	Mar. 31, 2014 CreXus Participation sold
Business Acquisition [Line Items]
Cash consideration transferred				$ 876,267
Fair value of equity interest in CreXus held before the business combination				106,521
Business Combination, Consideration Transferred, Including Equity Interest in Acquiree Held Prior to Combination				982,788
Recognized amounts of identifiable assets acquired and liabilities assumed
Cash and cash equivalents				151,843
Recognized amounts of identifiable assets					796,950	3,485
Other assets				5,617
Mortgages payable				(19,376)
Participation sold							(14,352)
Accounts payable and accrued expenses				(12,729)
Total identifiable net assets				911,438
Goodwill	94,781	94,781	[1]	71,350
Recognized amounts of identifiable assets				$ 982,788

[1] Derived from the audited consolidated financial statements at December 31, 2013.