PHC Certificates - Additional Information (Details)	3 Months Ended	6 Months Ended
	Jun. 30, 2018 USD ($) Integer	Jun. 30, 2018 USD ($) Integer
Schedule Of Available For Sale Securities [Line Items]
Impairment charge	$ 831,062	$ 831,062
LIFERS [Member]
Schedule Of Available For Sale Securities [Line Items]
Available-for-Sale Securities, Ownership Percentage		100.00%
Public housing capital fund trusts [Member]
Schedule Of Available For Sale Securities [Line Items]
Number of Available for Sale Securities, Public Housing Authorities | Integer	3	3
Impairment charge	$ 831,000	$ 831,000