Fair Value of Financial Instruments - Additional Information (Details)	Dec. 31, 2019	Dec. 31, 2018
Public housing capital fund trusts [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Weighted average effective yield	5.20%	5.50%
Taxable Bonds [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Weighted average effective yield	8.80%	9.10%
MRBs and Bond Purchase Commitments [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Weighted average effective yield	3.80%	4.60%
Effective rate - minimum [Member] | Public housing capital fund trusts [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Effective rate	4.40%	5.30%
Effective rate - minimum [Member] | Taxable Bonds [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Effective rate	8.70%	8.30%
Effective rate - minimum [Member] | MRBs and Bond Purchase Commitments [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Effective rate	2.40%	3.30%
Effective rate - maximum [Member] | Public housing capital fund trusts [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Effective rate	5.30%	6.00%
Effective rate - maximum [Member] | Taxable Bonds [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Effective rate	8.90%	9.30%
Effective rate - maximum [Member] | MRBs and Bond Purchase Commitments [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Effective rate	8.50%	9.10%