Concentration of Credit and Other Risks - Concentration of Credit Risk - Single-Family Credit Guarantee Portfolio (Details)
|
12 Months Ended |
Dec. 31, 2019 |
Dec. 31, 2018 |
| Concentration Risk [Line Items] |
|
|
| Serious delinquency rate |
0.63%
|
0.69%
|
| West |
|
|
| Concentration Risk [Line Items] |
|
|
| Serious delinquency rate |
0.36%
|
0.38%
|
| Northeast |
|
|
| Concentration Risk [Line Items] |
|
|
| Serious delinquency rate |
0.87%
|
0.96%
|
| North Central |
|
|
| Concentration Risk [Line Items] |
|
|
| Serious delinquency rate |
0.61%
|
0.63%
|
| Southeast |
|
|
| Concentration Risk [Line Items] |
|
|
| Serious delinquency rate |
0.73%
|
0.90%
|
| Southwest |
|
|
| Concentration Risk [Line Items] |
|
|
| Serious delinquency rate |
0.54%
|
0.57%
|
| FLORIDA |
|
|
| Concentration Risk [Line Items] |
|
|
| Serious delinquency rate |
0.77%
|
1.01%
|
| ILLINOIS |
|
|
| Concentration Risk [Line Items] |
|
|
| Serious delinquency rate |
0.85%
|
0.86%
|
| NEW JERSEY |
|
|
| Concentration Risk [Line Items] |
|
|
| Serious delinquency rate |
1.08%
|
1.24%
|
| CALIFORNIA |
|
|
| Concentration Risk [Line Items] |
|
|
| Serious delinquency rate |
0.34%
|
0.35%
|
| NEW YORK |
|
|
| Concentration Risk [Line Items] |
|
|
| Serious delinquency rate |
1.21%
|
1.37%
|
| All Other |
|
|
| Concentration Risk [Line Items] |
|
|
| Serious delinquency rate |
0.59%
|
0.64%
|
| Core single-family loan portfolio |
|
|
| Concentration Risk [Line Items] |
|
|
| Serious delinquency rate |
0.26%
|
0.22%
|
| Legacy and relief refinance single-family loan portfolio |
|
|
| Concentration Risk [Line Items] |
|
|
| Serious delinquency rate |
1.84%
|
1.93%
|
| Single-family UPB |
|
|
| Concentration Risk [Line Items] |
|
|
| Concentration risk percentage |
100.00%
|
100.00%
|
| Single-family UPB | West |
|
|
| Concentration Risk [Line Items] |
|
|
| Concentration risk percentage |
30.00%
|
30.00%
|
| Single-family UPB | Northeast |
|
|
| Concentration Risk [Line Items] |
|
|
| Concentration risk percentage |
24.00%
|
24.00%
|
| Single-family UPB | North Central |
|
|
| Concentration Risk [Line Items] |
|
|
| Concentration risk percentage |
16.00%
|
16.00%
|
| Single-family UPB | Southeast |
|
|
| Concentration Risk [Line Items] |
|
|
| Concentration risk percentage |
16.00%
|
16.00%
|
| Single-family UPB | Southwest |
|
|
| Concentration Risk [Line Items] |
|
|
| Concentration risk percentage |
14.00%
|
14.00%
|
| Single-family UPB | FLORIDA |
|
|
| Concentration Risk [Line Items] |
|
|
| Concentration risk percentage |
6.00%
|
6.00%
|
| Single-family UPB | ILLINOIS |
|
|
| Concentration Risk [Line Items] |
|
|
| Concentration risk percentage |
4.00%
|
5.00%
|
| Single-family UPB | NEW JERSEY |
|
|
| Concentration Risk [Line Items] |
|
|
| Concentration risk percentage |
3.00%
|
3.00%
|
| Single-family UPB | CALIFORNIA |
|
|
| Concentration Risk [Line Items] |
|
|
| Concentration risk percentage |
17.00%
|
18.00%
|
| Single-family UPB | NEW YORK |
|
|
| Concentration Risk [Line Items] |
|
|
| Concentration risk percentage |
5.00%
|
5.00%
|
| Single-family UPB | All Other |
|
|
| Concentration Risk [Line Items] |
|
|
| Concentration risk percentage |
65.00%
|
63.00%
|
| Single-family UPB | Core single-family loan portfolio |
|
|
| Concentration Risk [Line Items] |
|
|
| Concentration risk percentage |
85.00%
|
82.00%
|
| Single-family UPB | Legacy and relief refinance single-family loan portfolio |
|
|
| Concentration Risk [Line Items] |
|
|
| Concentration risk percentage |
15.00%
|
18.00%
|
| Single-family Credit Losses |
|
|
| Concentration Risk [Line Items] |
|
|
| Concentration risk percentage |
100.00%
|
100.00%
|
| Single-family Credit Losses | West |
|
|
| Concentration Risk [Line Items] |
|
|
| Concentration risk percentage |
12.00%
|
17.00%
|
| Single-family Credit Losses | Northeast |
|
|
| Concentration Risk [Line Items] |
|
|
| Concentration risk percentage |
36.00%
|
39.00%
|
| Single-family Credit Losses | North Central |
|
|
| Concentration Risk [Line Items] |
|
|
| Concentration risk percentage |
20.00%
|
19.00%
|
| Single-family Credit Losses | Southeast |
|
|
| Concentration Risk [Line Items] |
|
|
| Concentration risk percentage |
24.00%
|
18.00%
|
| Single-family Credit Losses | Southwest |
|
|
| Concentration Risk [Line Items] |
|
|
| Concentration risk percentage |
8.00%
|
7.00%
|
| Single-family Credit Losses | FLORIDA |
|
|
| Concentration Risk [Line Items] |
|
|
| Concentration risk percentage |
14.00%
|
10.00%
|
| Single-family Credit Losses | ILLINOIS |
|
|
| Concentration Risk [Line Items] |
|
|
| Concentration risk percentage |
10.00%
|
9.00%
|
| Single-family Credit Losses | NEW JERSEY |
|
|
| Concentration Risk [Line Items] |
|
|
| Concentration risk percentage |
9.00%
|
9.00%
|
| Single-family Credit Losses | CALIFORNIA |
|
|
| Concentration Risk [Line Items] |
|
|
| Concentration risk percentage |
8.00%
|
11.00%
|
| Single-family Credit Losses | NEW YORK |
|
|
| Concentration Risk [Line Items] |
|
|
| Concentration risk percentage |
7.00%
|
11.00%
|
| Single-family Credit Losses | All Other |
|
|
| Concentration Risk [Line Items] |
|
|
| Concentration risk percentage |
52.00%
|
50.00%
|
| Single-family Credit Losses | Core single-family loan portfolio |
|
|
| Concentration Risk [Line Items] |
|
|
| Concentration risk percentage |
18.00%
|
10.00%
|
| Single-family Credit Losses | Legacy and relief refinance single-family loan portfolio |
|
|
| Concentration Risk [Line Items] |
|
|
| Concentration risk percentage |
82.00%
|
90.00%
|