Summary of Significant Accounting Policies - Additional Information (Detail) (USD $)	3 Months Ended
	Mar. 31, 2015 Segment	Dec. 31, 2014
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Assets attributable to consolidated VIE		$ 0
Liabilities attributable to consolidated VIE		0
Income accrual, description	Income accrual is generally suspended for loans at the earlier of the date at which payments become 90 days past due or when, in the opinion of our Manager, recovery of income and principal becomes doubtful.
Cash and cash equivalents, description	Cash and cash equivalents represent cash held in banks, cash on hand, and liquid investments with original maturities of three months or less.
Number of operating segment	2
Cash and Cash Equivalents [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Expected loss	$ 0