Fair Value of Financial Instruments (Details) (USD $) In Thousands, unless otherwise specified	Jun. 30, 2013		Dec. 31, 2012
Financial assets:
Lending Investments Carrying Value	$ 0	[1],[2]	$ 784,135	[1],[2]
Lending investments, Fair Value	0	[1],[2]	816,283	[1],[2]
CMBS, Carrying Value	0	[2]	932,265	[2]
CMBS, Fair Value	0	[2]	932,265	[2]
Derivative instruments, Carrying Value	0	[2]	173	[2]
Derivative instruments, Fair Value	0	[2]	173	[2]
Retained CDO Bonds, Carring Value	7,645	[3]	0	[3]
Retained CDO Bonds, Fair Value	7,645	[3]	0	[3]
Financial liabilities:
Collateralized debt obligations, Carrying Value	0	[1],[2]	2,188,579	[1],[2]
Collateralized debt obligations, Fair Value	0	[1],[2]	1,474,236	[1],[2]
Derivative instruments, Carrying Value	0	[2]	173,623	[2]
Derivative instruments, Fair Value	0	[2]	173,623	[2]
Mortgage note payable, Carrying Value	48,714	[1]	0	[1]
Mortgage note payable, Fair Value	$ 48,218	[1]	$ 0	[1]

[1] Lending investments, mortgages notes payable, and CDOs are classified as Level III due to the significance of unobservable inputs which are based upon management assumptions.

[2] In connection with the disposal of Gramercy Finance, lending investments, CMBS investments, derivative instruments, and collateralized debt obligations were classified as held-for-sale as of December 31, 2012.

[3] Retained CDO Bonds represent the CDOs' subordinate bonds, preferred shares, and ordinary shares, which were retained subsequent to the disposal of Gramercy Finance and were previously eliminated in consolidation.