AVAILABLE-FOR-SALE SECURITIES (Tables)

12 Months Ended

Sep. 30, 2023

Debt Securities, Available-for-Sale [Abstract]

Amortized Cost and Estimated Fair Values of Available For Sale Securities

The following table details the amortized costs and fair values of our available-for-sale securities. See Note 4 for additional information regarding the fair value of available-for-sale securities.

$ in millions	Cost basis		Gross unrealized gains		Gross unrealized losses		Fair value
September 30, 2023
Agency residential MBS	$	4,865	$	—	$	(654)	$	4,211
Agency commercial MBS	1,464		—		(211)		1,253
Agency CMOs	1,448		—		(265)		1,183
Other agency obligations	710		—		(31)		679
Non-agency residential MBS	527		—		(64)		463
U.S. Treasuries	1,261		—		(21)		1,240
Corporate bonds	140		—		(6)		134
Other	18		—		—		18
Total available-for-sale securities	$	10,433	$	—	$	(1,252)	$	9,181
September 30, 2022
Agency residential MBS	$	5,662	$	—	$	(668)	$	4,994
Agency commercial MBS	1,518		—		(208)		1,310
Agency CMOs	1,637		—		(233)		1,404
Other agency obligations	613		—		(31)		582
Non-agency residential MBS	492		—		(41)		451
U.S Treasuries	1,014		—		(28)		986
Corporate bonds	146		—		(5)		141
Other	18		—		(1)		17
Total available-for-sale securities	$	11,100	$	—	$	(1,215)	$	9,885

Contractual Maturities, Amortized Cost, Carrying Values, and Current Yields for Available For Sales Securities

The following table details the contractual maturities, amortized costs, carrying values and current yields for our available-for-sale securities.  Weighted-average yields are calculated on a taxable-equivalent basis based on estimated annual income divided by the average amortized cost of these securities. Since our MBS and CMO available-for-sale securities are backed by mortgages, actual maturities may differ from contractual maturities because borrowers may have the right to prepay obligations without prepayment penalties. As a result, as of September 30, 2023, the weighted-average life of our available-for-sale securities portfolio, after factoring in estimated prepayments, was approximately 4.2 years.

	September 30, 2023
$ in millions	Within one year			After one but within five years			After five but within ten years			After ten years			Total
Agency residential MBS
Amortized cost	$	—		$	125		$	2,140		$	2,600		$	4,865
Carrying value	$	—		$	120		$	1,886		$	2,205		$	4,211
Weighted-average yield	—		%	2.51		%	1.29		%	1.92		%	1.66		%
Agency commercial MBS
Amortized cost	$	18		$	898		$	498		$	50		$	1,464
Carrying value	$	18		$	800		$	396		$	39		$	1,253
Weighted-average yield	3.45		%	1.60		%	1.20		%	1.87		%	1.50		%
Agency CMOs
Amortized cost	$	—		$	8		$	42		$	1,398		$	1,448
Carrying value	$	—		$	8		$	37		$	1,138		$	1,183
Weighted-average yield	—		%	2.30		%	1.52		%	1.57		%	1.57		%
Other agency obligations
Amortized cost	$	90		$	530		$	80		$	10		$	710
Carrying value	$	88		$	509		$	73		$	9		$	679
Weighted-average yield	2.46		%	3.29		%	3.43		%	3.07		%	3.20		%
Non-agency residential MBS
Amortized cost	$	—		$	—		$	—		$	527		$	527
Carrying value	$	—		$	—		$	—		$	463		$	463
Weighted-average yield	—		%	—		%	—		%	4.22		%	4.22		%
U.S. Treasuries
Amortized cost	$	753		$	508		$	—		$	—		$	1,261
Carrying value	$	740		$	500		$	—		$	—		$	1,240
Weighted-average yield	2.53		%	4.06		%	—		%	—		%	3.14		%
Corporate bonds
Amortized cost	$	31		$	86		$	23		$	—		$	140
Carrying value	$	30		$	83		$	21		$	—		$	134
Weighted-average yield	4.70		%	6.43		%	5.02		%	—		%	5.81		%
Other
Amortized cost	$	—		$	5		$	5		$	8		$	18
Carrying value	$	—		$	5		$	4		$	9		$	18
Weighted-average yield	—		%	7.30		%	5.22		%	8.32		%	7.25		%
Total available-for-sale securities
Amortized cost	$	892		$	2,160		$	2,788		$	4,593		$	10,433
Carrying value	$	876		$	2,025		$	2,417		$	3,863		$	9,181
Weighted-average yield	2.61		%	2.86		%	1.38		%	2.09		%	2.11		%

Available For Sale Securities in a Continuous Unrealized Loss Position

The following table details the gross unrealized losses and fair values of securities that were in a loss position at the reporting period end, aggregated by investment category and length of time the individual securities have been in a continuous unrealized loss position.

	Less than 12 months				12 months or more				Total
$ in millions	Estimated fair value		Unrealized losses		Estimated fair value		Unrealized losses		Estimated fair value		Unrealized losses
September 30, 2023
Agency residential MBS	$	73	$	(3)	$	4,119	$	(651)	$	4,192	$	(654)
Agency commercial MBS	3		—		1,250		(211)		1,253		(211)
Agency CMOs	—		—		1,183		(265)		1,183		(265)
Other agency obligations	97		(1)		582		(30)		679		(31)
Non-agency residential MBS	62		(1)		401		(63)		463		(64)
U.S. Treasuries	120		—		995		(21)		1,115		(21)
Corporate bonds	13		—		78		(6)		91		(6)
Other	5		—		9		—		14		—
Total	$	373	$	(5)	$	8,617	$	(1,247)	$	8,990	$	(1,252)
September 30, 2022
Agency residential MBS	$	2,165	$	(226)	$	2,829	$	(442)	$	4,994	$	(668)
Agency commercial MBS	494		(41)		816		(167)		1,310		(208)
Agency CMOs	337		(32)		1,067		(201)		1,404		(233)
Other agency obligations	582		(31)		—		—		582		(31)
Non-agency residential MBS	451		(41)		—		—		451		(41)
U.S. Treasuries	982		(28)		4		—		986		(28)
Corporate bonds	128		(5)		—		—		128		(5)
Other	17		(1)		—		—		17		(1)
Total	$	5,156	$	(405)	$	4,716	$	(810)	$	9,872	$	(1,215)