Segment Reporting (Narrative) (Details) ft² in Millions	12 Months Ended
	Dec. 31, 2015 ft² property segment loan state security	Dec. 31, 2014 loan security
Segment Reporting Information [Line Items]
Number of operating segments | segment	2
Number of loans held for investment | loan	10	14
Commercial Mortgage Backed Securities [Member]
Segment Reporting Information [Line Items]
Number of securities acquired | security	10	10
REI Segment [Member] | Consolidated Properties [Member]
Segment Reporting Information [Line Items]
Number of properties owned | property	4,435
Square feet of property | ft²	99.6
Number of states in which entity operates | state	49
Percentage of rentable space leased	98.60%
Real estate property, weighted average remaining lease term	10 years 7 months 6 days