Fair Value (Details 2) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2012
ExcludingSecuritizationVehiclesMember | Securities
Number of loans	12
Aggregate principal balance	$ 135,380
ExcludingSecuritizationVehiclesMember | Loss Severity 0-25%
Number of loans	15
Aggregate principal balance	176,195
ExcludingSecuritizationVehiclesMember | Loss Severity 0-25% | Securities
Number of loans	5
Aggregate principal balance	17,114
ExcludingSecuritizationVehiclesMember | Loss Severity 26-50%
Number of loans	1
Aggregate principal balance	1,212
ExcludingSecuritizationVehiclesMember | Loss Severity 76-100%
Number of loans	10
Aggregate principal balance	216,538
ExcludingSecuritizationVehiclesMember | Loss Severity 76-100% | Securities
Number of loans	7
Aggregate principal balance	118,266
ExcludingSecuritizationVehiclesMember | Senior Mortgage Loans
Number of loans	2
Aggregate principal balance	32,869
ExcludingSecuritizationVehiclesMember | Senior Mortgage Loans | Loss Severity 0-25%
Number of loans	2
Aggregate principal balance	32,869
ExcludingSecuritizationVehiclesMember | Subordinated interests in mortgages
Number of loans	6
Aggregate principal balance	97,143
ExcludingSecuritizationVehiclesMember | Subordinated interests in mortgages | Loss Severity 0-25%
Number of loans	3
Aggregate principal balance	52,483
ExcludingSecuritizationVehiclesMember | Subordinated interests in mortgages | Loss Severity 26-50%
Number of loans	1
Aggregate principal balance	1,212
ExcludingSecuritizationVehiclesMember | Subordinated interests in mortgages | Loss Severity 76-100%
Number of loans	2
Aggregate principal balance	43,448
ExcludingSecuritizationVehiclesMember | Mezzanine Loans
Number of loans	6
Aggregate principal balance	128,553
ExcludingSecuritizationVehiclesMember | Mezzanine Loans | Loss Severity 0-25%
Number of loans	5
Aggregate principal balance	73,729
ExcludingSecuritizationVehiclesMember | Mezzanine Loans | Loss Severity 76-100%
Number of loans	1
Aggregate principal balance	54,824
CT Legacy REIT
Number of loans	26
Aggregate principal balance	$ 393,945