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	6 Months Ended
	Jun. 30, 2013
Securitization Vehicles [Line Items]
Principal Balance	$ 74,472
Book Value, beginning year	139,184
Book Value, ending year	74,472
Coupon	1.79%
All-In Cost	1.79%
Maturity Date	Jul. 31, 2039
CT CDO I [Member]
Securitization Vehicles [Line Items]
Principal Balance	74,472
Book Value, beginning year	91,131
Book Value, ending year	74,472
Coupon	1.79%
All-In Cost	1.79%
Maturity Date	Jul. 31, 2039
GSMS 2006-FL8A [Member]
Securitization Vehicles [Line Items]
Principal Balance
Book Value, beginning year	48,053
Book Value, ending year
Coupon
All-In Cost
Maturity Date	Jul. 31, 2039