Segment Reporting Footnote Tagging (Details)	12 Months Ended
	Dec. 31, 2016 Property Unit Integer Segment	Jan. 31, 2016 Security	Oct. 31, 2015 Unit
Segment Reporting Information [Line Items]
Number of Reportable Segments | Segment	4
Units | Unit			2
Other Investments [Member]
Segment Reporting Information [Line Items]
Assets percentage	25.00%
Commercial Real Estate [Member]
Segment Reporting Information [Line Items]
Number of collateralized securities | Integer	1
MBS Securities Investments [Member]
Segment Reporting Information [Line Items]
Number of partnership securities sold and eliminated. | Security		3
Mortgage Revenue Bond Investments Segment [Member]
Segment Reporting Information [Line Items]
Number of Available for Sale Securities | Integer	83
Mortgage Revenue Bond Investments Segment [Member] | Residential Properties [Member]
Segment Reporting Information [Line Items]
Number of Available for Sale Securities | Integer	83
Units | Unit	9,968
Real Estate [Member]
Segment Reporting Information [Line Items]
Units | Unit	2,004
Number of Real Estate Properties | Property	7