Investments in Securities (Tables)

9 Months Ended

Sep. 30, 2020

Investments, Debt and Equity Securities [Abstract]

Investments In Trading Securities [Table Text Block]

The following table displays our investments in trading securities.

	As of
	September 30, 2020			December 31, 2019
	(Dollars in millions)
Mortgage-related securities:
Fannie Mae		$	2,750		$	3,424
Other agency(1)		3,518			4,490
Private-label and other mortgage securities		158			629
Total mortgage-related securities (includes $850 million and $896 million, respectively,     related to consolidated trusts)		6,426			8,543
Non-mortgage-related securities:
U.S. Treasury securities		135,972			39,501
Other securities		74			79
Total non-mortgage-related securities		136,046			39,580
Total trading securities		$	142,472		$	48,123

(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 September 30,				For the Nine Months Ended September 30,
		2020		2019		2020		2019
	(Dollars in millions)
Net trading gains (losses)		$	(91)	$	95	$	691	$	370
Net trading gains (losses) recognized in the period related to securities still held at period end		(71)		82		448		298

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 September 30, 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		$	1,195	$	—	$	102		$	(14)	$	1,283
Other agency(2)		85		—		11			—		96
Alt-A and subprime private-label securities		4		—		2			—		6
Mortgage revenue bonds		249		(3)		9			—		255
Other mortgage-related securities		247		—		8			—		255
Total		$	1,780	$	(3)	$	132		$	(14)	$	1,895

	As of December 31, 2019
	Total Amortized Cost(1)(3)			Gross Unrealized Gains			Gross Unrealized Losses			Total Fair Value(1)
	(Dollars in millions)
Fannie Mae		$	1,445		$	85		$	(10)	$	1,520
Other agency(2)		183			15			—		198
Alt-A and subprime private-label securities		34			23			—		57
Mortgage revenue bonds		309			9			(3)		315
Other mortgage-related securities		310			5			(1)		314
Total		$	2,281		$	137		$	(14)	$	2,404

(1)We exclude from amortized cost and fair value accrued interest of $7 million and $10 million as of September 30, 2020 and December 31, 2019, 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.

(3)Prior to our adoption of the CECL standard, total amortized cost represented the unpaid principal balance, unamortized premiums, discounts and other cost basis adjustments, as well as temporary impairments recognized in “Investment gains, net” in our consolidated statements of operations and comprehensive income.

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 September 30, 2020
	Less Than 12 Consecutive Months					12 Consecutive Months or Longer
	Gross Unrealized Losses in AOCI			Fair Value		Gross Unrealized Losses in AOCI			Fair Value
	(Dollars in millions)
Fannie Mae		$	(2)	$	72		$	(12)	$	90
Mortgage revenue bonds		—		—			—		—
Other mortgage-related securities		—		—			—		—
Total		$	(2)	$	72		$	(12)	$	90
	As of December 31, 2019
	Less Than 12 Consecutive Months					12 Consecutive Months or Longer
	Gross Unrealized Losses			Fair Value		Gross Unrealized Losses			Fair Value
	(Dollars in millions)
Fannie Mae		$	—	$	—		$	(10)	$	337
Mortgage revenue bonds		—		—			(3)		3
Other mortgage-related securities		(1)		130			—		—
Total		$	(1)	$	130		$	(13)	$	340

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 September 30,				For the Nine Months Ended September 30,
		2020		2019		2020		2019
	(Dollars in millions)
Gross realized gains		$	15	$	—	$	45	$	171
Total proceeds (excludes initial sale of securities from new portfolio     securitizations)		137		—		258		376

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
	September 30, 2020
	(Dollars in millions)
Net unrealized gains on AFS securities for which we have not recorded an allowance for credit     losses	$	93
Other	27
Accumulated other comprehensive income	$	120

	As of
	December 31, 2019
	(Dollars in millions)
Net unrealized gains on AFS securities for which we have not recorded OTTI	$	97
Other	34
Accumulated other comprehensive income	$	131

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 September 30, 2020
	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		$	1,195	$	1,283		$	—	$	—		$	6	$	6		$	88	$	100		$	1,101	$	1,177
Other agency		85		96			—		—			—		—			10		11			75		85
Alt-A and subprime private-label securities		4		6			—		—			—		—			2		3			2		3
Mortgage revenue bonds		246		255			1		1			28		30			24		24			193		200
Other mortgage-related securities		247		255			—		—			—		—			20		21			227		234
Total		$	1,777	$	1,895		$	1	$	1		$	34	$	36		$	144	$	159		$	1,598	$	1,699

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