Real Estate Debt Investments (Details 2) (USD $) In Thousands, unless otherwise specified	6 Months Ended
	Jun. 30, 2014 investment
Credit Quality Monitoring
Maturity period of debt instruments depending upon the asset type	4 years 4 months 12 days
Number of CRE debt investments contributing to more than 10% of interest income (investments)	0
Minimum
Credit Quality Monitoring
Period past due on contractual debt service payments for debt investments to be categorized as non-performing loans	90 days
Initial Maturity
Maturities of principal amounts of CRE debt investments
July 1 to December 31, 2014	$ 129,685
Years Ending December 31:
2015	378,320
2016	313,600
2017	187,300
2018	0
Thereafter	308,013
Total	1,316,918
Maturity Including Extensions
Maturities of principal amounts of CRE debt investments
July 1 to December 31, 2014	0
Years Ending December 31:
2015	12,480
2016	175,205
2017	320,320
2018	413,600
Thereafter	395,313
Total	$ 1,316,918