Mortgage Loans TDRs with Sub Defaults (Details) $ in Millions	3 Months Ended	6 Months Ended
Jun. 30, 2019 USD ($) contracts	Jun. 30, 2018 USD ($) contracts	Jun. 30, 2019 USD ($) contracts	Jun. 30, 2018 USD ($) contracts
Financing Receivable, Modifications [Line Items]
Number of loans troubled debt restructurings subsequent default \| contracts	4,547	4,568	9,706	10,273
Recorded investment troubled debt restructurings subsequent default \| $	$ 693	$ 674	$ 1,470	$ 1,526
Single-family [Member]
Financing Receivable, Modifications [Line Items]
Number of loans troubled debt restructurings subsequent default \| contracts	4,546	4,568	9,705	10,272
Recorded investment troubled debt restructurings subsequent default \| $	$ 687	$ 674	$ 1,464	$ 1,524
Single-family [Member] \| Primary [Member]
Financing Receivable, Modifications [Line Items]
Number of loans troubled debt restructurings subsequent default \| contracts	4,047	3,834	8,563	8,652
Recorded investment troubled debt restructurings subsequent default \| $	$ 606	$ 554	$ 1,279	$ 1,255
Single-family [Member] \| Government [Member]
Financing Receivable, Modifications [Line Items]
Number of loans troubled debt restructurings subsequent default \| contracts	10	15	28	29
Recorded investment troubled debt restructurings subsequent default \| $	$ 2	$ 2	$ 5	$ 4
Single-family [Member] \| Alt-A
Financing Receivable, Modifications [Line Items]
Number of loans troubled debt restructurings subsequent default \| contracts	379	588	850	1,265
Recorded investment troubled debt restructurings subsequent default \| $	$ 58	$ 92	$ 131	$ 201
Single-family [Member] \| Other [Member]
Financing Receivable, Modifications [Line Items]
Number of loans troubled debt restructurings subsequent default \| contracts	110	131	264	326
Recorded investment troubled debt restructurings subsequent default \| $	$ 21	$ 26	$ 49	$ 64
Multifamily [Member]
Financing Receivable, Modifications [Line Items]
Number of loans troubled debt restructurings subsequent default \| contracts	1	0	1	1
Recorded investment troubled debt restructurings subsequent default \| $	$ 6	$ 0	$ 6	$ 2

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Number of financing receivables that have been modified by troubled debt restructurings within the previous 12 months and for which there was a payment default.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 50
-Paragraph 34
-URI http://asc.fasb.org/extlink&oid=84173941&loc=SL6953682-111524

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Amount of investment related to financing receivables modified by troubled debt restructurings within the previous 12 months, for which there was a payment default.

+ References

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