Debt Obligations - Balances of Each Entity's Outstanding Securitized Debt Obligations, their Respective Coupons and All-in Effective Costs, Including Amortization of Fees and Expenses (Detail) (USD $) In Thousands, unless otherwise specified	9 Months Ended
	Sep. 30, 2013
Non-Recourse Securitized Debt Obligations
Principal Balance	$ 74,203
Book Value, beginning year	139,184
Book Value, ending year	74,203
Coupon	L+1.60 %
All-In Cost	L+1.60 %
Maturity Date	Jul. 31, 2039
CT CDO I [Member]
Non-Recourse Securitized Debt Obligations
Principal Balance	74,203
Book Value, beginning year	91,131
Book Value, ending year	74,203
Coupon	L+1.60 %
All-In Cost	L+1.60 %
Maturity Date	Jul. 31, 2039
GSMS 2006-FL8A [Member]
Non-Recourse Securitized Debt Obligations
Principal Balance
Book Value, beginning year	48,053
Book Value, ending year
Coupon
All-In Cost
Maturity Date	Jul. 31, 2039