Subsequent Events - Additional Information (Detail) (USD $) In Thousands, except Share data, unless otherwise specified	12 Months Ended			1 Months Ended	0 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2013 Subsequent Event [Member] SecurityLoan	Jan. 29, 2014 Subsequent Event [Member] Wells Fargo [Member]	Jan. 14, 2014 Subsequent Event [Member] Class A Common Stock [Member]
Subsequent Event [Line Items]
Common stock issued, shares	25,875,000	669,047			9,775,000
Common stock offering price per share					$ 26.75
Proceeds from shares issued, net of underwriting discounts and other offering expenses	$ 633,807	$ 10,000			$ 256,100
Facility size			286,400	32,000
Loan commitments funded at closing			$ 208,800
Number of loans originated			3
Maturity period				From February 9, 2014 to April 9, 2014
Extended term of agreement period				10 months