Mortgage Loans - Nonaccrual Loans (Details) - USD ($) $ in Millions	12 Months Ended
Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Amortized cost, nonaccrual loans	$ 12,517	$ 20,496	$ 28,574	$ 27,981
Interest income recognized, nonaccrual loans	298	328	583
Single-family
Accrued interest receivable written off	61	163	206
Amortized cost, nonaccrual loans	10,317	19,237	26,505	27,546
Interest income recognized, nonaccrual loans	223	314	524
Single-family \| 20- and 30-year or more, amortizing fixed-rate
Amortized cost, nonaccrual loans	9,447	17,599	22,907	23,427
Interest income recognized, nonaccrual loans	207	292	461
Single-family \| 15-year or less, amortizing fixed-rate
Amortized cost, nonaccrual loans	200	430	853	858
Interest income recognized, nonaccrual loans	4	6	15
Single-family \| Adjustable-rate
Amortized cost, nonaccrual loans	53	107	270	288
Interest income recognized, nonaccrual loans	1	1	5
Single-family \| Other
Amortized cost, nonaccrual loans	617	1,101	2,475	2,973
Interest income recognized, nonaccrual loans	11	15	43
Multifamily
Accrued interest receivable written off	1	1	19
Amortized cost, nonaccrual loans	2,200	1,259	2,069	$ 435
Interest income recognized, nonaccrual loans	$ 75	$ 14	$ 59

Amount of writeoff of accrued interest on financing receivable recognized by reversing interest income.

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 326
-SubTopic 20
-Section 50
-Paragraph 3D
-URI https://asc.fasb.org/extlink&oid=124255953&loc=SL120267969-210447

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+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 326
-SubTopic 20
-Section 50
-Paragraph 16
-Subparagraph (b)
-URI https://asc.fasb.org/extlink&oid=124255953&loc=SL82919258-210447

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+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 50
-Paragraph 7
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-URI https://asc.fasb.org/extlink&oid=123577603&loc=d3e5111-111524

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 326
-SubTopic 20
-Section 50
-Paragraph 16
-Subparagraph (a)
-URI https://asc.fasb.org/extlink&oid=124255953&loc=SL82919258-210447

Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Publisher SEC
-Name Regulation S-K (SK)
-Number 229
-Section 1405
-Paragraph (a)
-Subparagraph (3)

Reference 4: http://www.xbrl.org/2003/role/disclosureRef
-Publisher SEC
-Name Regulation S-K (SK)
-Number 229
-Section 1405
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