Investments in Securities (Tables)

3 Months Ended

Mar. 31, 2021

Investments, Debt and Equity Securities [Abstract]

Investments In Trading Securities [Table Text Block]

The following table displays our investments in trading securities.

	As of
	March 31, 2021			December 31, 2020
	(Dollars in millions)
Mortgage-related securities:
Fannie Mae		$	1,985		$	2,404
Other agency(1)		3,440			3,451
Private-label and other mortgage securities		157			158
Total mortgage-related securities (includes $741 million and $793 million, respectively, related to consolidated trusts)		5,582			6,013
Non-mortgage-related securities:
U.S. Treasury securities		105,601			130,456
Other securities		73			73
Total non-mortgage-related securities		105,674			130,529
Total trading securities		$	111,256		$	136,542

(1)Consists of Freddie Mac and Ginnie Mae mortgage-related securities.

Schedule of Trading Securities Gains (Losses), Net [Table Text Block]

The following table displays information about our net trading gains (losses).

		For the Three Months Ended March 31,
		2021		2020
	(Dollars in millions)
Net trading gains (losses)		$	(758)	$	647
Net trading gains (losses) recognized in the period related to securities still held at period end		(759)		591

Schedule of Available-for-sale Securities Reconciliation [Table Text Block]

The following tables display the amortized cost, allowance for credit losses, gross unrealized gains and losses in accumulated other comprehensive income (loss) (“AOCI”), and fair value by major security type for AFS securities.

	As of March 31, 2021
	Total Amortized Cost(1)			Allowance for Credit Losses		Gross Unrealized Gains in AOCI		Gross Unrealized Losses in AOCI			Total Fair Value(1)
	(Dollars in millions)
Fannie Mae		$	988	$	—	$	59		$	(11)	$	1,036
Other agency(2)		32		—		2			—		34
Alt-A and subprime private-label securities		3		—		2			—		5
Mortgage revenue bonds		187		(3)		7			—		191
Other mortgage-related securities		230		—		6			—		236
Total		$	1,440	$	(3)	$	76		$	(11)	$	1,502

	As of December 31, 2020
	Total Amortized Cost(1)			Allowance for Credit Losses			Gross Unrealized Gains in AOCI			Gross Unrealized Losses in AOCI			Total Fair Value(1)
	(Dollars in millions)
Fannie Mae		$	1,094		$	—		$	86		$	(12)	$	1,168
Other agency(2)		59			—			6			—		65
Alt-A and subprime private-label securities		4			—			2			—		6
Mortgage revenue bonds		211			(3)			8			—		216
Other mortgage-related securities		238			—			4			—		242
Total		$	1,606		$	(3)		$	106		$	(12)	$	1,697

(1)We exclude from amortized cost and fair value accrued interest of $5 million and $6 million as of March 31, 2021 and December 31, 2020, respectively, which we record in “Other assets” in our condensed consolidated balance sheets.

(2)Other agency securities consist of securities issued by Freddie Mac and Ginnie Mae.

Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value [Table Text Block]

The following tables display additional information regarding gross unrealized losses and fair value by major security type for AFS securities in an unrealized loss position, excluding allowance for credit losses.

	As of
	March 31, 2021										December 31, 2020
	Less Than 12 Consecutive Months					12 Consecutive Months or Longer					Less Than 12 Consecutive Months					12 Consecutive Months or Longer
	Gross Unrealized Losses in AOCI			Fair Value		Gross Unrealized Losses in AOCI			Fair Value		Gross Unrealized Losses in AOCI			Fair Value		Gross Unrealized Losses in AOCI			Fair Value
	(Dollars in millions)
Fannie Mae		$	—	$	—		$	(11)	$	131		$	(1)	$	40		$	(11)	$	94
Total		$	—	$	—		$	(11)	$	131		$	(1)	$	40		$	(11)	$	94

Schedule of Realized Gain (Loss) [Table Text Block]

The following table displays the gross realized gains and proceeds on sales of AFS securities.

		For the Three Months Ended March 31,
		2021		2020
	(Dollars in millions)
Gross realized gains		$	13	$	21
Total proceeds (excludes initial sale of securities from new portfolio securitizations)		115		50

Schedule of Accumulated Other Comprehensive Income (Loss) [Table Text Block]

The following tables display net unrealized gains on AFS securities and other amounts accumulated within our accumulated other comprehensive income, net of tax.

	As of
	March 31, 2021		December 31, 2020
	(Dollars in millions)
Net unrealized gains on AFS securities for which we have not recorded an allowance for credit losses	$	51	$	74
Other	38		42
Accumulated other comprehensive income	$	89	$	116

Investments Classified by Contractual Maturity Date [Table Text Block]

The following table displays the amortized cost and fair value of our AFS securities by major security type and remaining contractual maturity, assuming no principal prepayments. The contractual maturity of mortgage-backed securities is not a reliable indicator of their expected life because borrowers generally have the right to prepay their obligations at any time.

	As of March 31, 2021
	Total Carrying Amount(1)			Total Fair Value		One Year or Less					After One Year Through Five Years					After Five Years Through Ten Years					After Ten Years
						Net Carrying Amount(1)			Fair Value		Net Carrying Amount(1)			Fair Value		Net Carrying Amount(1)			Fair Value		Net Carrying Amount(1)			Fair Value
	(Dollars in millions)
Fannie Mae		$	988	$	1,036		$	—	$	—		$	4	$	4		$	98	$	109		$	886	$	923
Other agency		32		34			—		—			—		—			1		1			31		33
Alt-A and subprime private-label securities		3		5			—		—			—		—			2		2			1		3
Mortgage revenue bonds		184		191			1		1			26		27			18		19			139		144
Other mortgage-related securities		230		236			—		—			—		—			18		20			212		216
Total		$	1,437	$	1,502		$	1	$	1		$	30	$	31		$	137	$	151		$	1,269	$	1,319

(1)     Net carrying amount consists of book value, net of allowance for credit losses on AFS debt securities.