AVAILABLE-FOR-SALE SECURITIES (Tables)

12 Months Ended

Sep. 30, 2024

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 2 for a discussion of our accounting policies applicable to 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, 2024
Agency residential MBS	$	4,147	$	3	$	(327)	$	3,823
Agency commercial MBS	1,415		—		(119)		1,296
Agency CMOs	1,394		1		(170)		1,225
U.S. Treasuries	706		—		(2)		704
Other agency obligations	565		—		(6)		559
Non-agency residential MBS	553		1		(27)		527
Corporate bonds	107		1		(2)		106
Other	19		1		—		20
Total available-for-sale securities	$	8,906	$	7	$	(653)	$	8,260
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
U.S Treasuries	1,261		—		(21)		1,240
Other agency obligations	710		—		(31)		679
Non-agency residential MBS	527		—		(64)		463
Corporate bonds	140		—		(6)		134
Other	18		—		—		18
Total available-for-sale securities	$	10,433	$	—	$	(1,252)	$	9,181

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

The following table details the contractual maturities, amortized costs, fair 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, the weighted-average life of our available-for-sale securities portfolio, after factoring in estimated prepayments, was approximately 3.8 years as of September 30, 2024.

	September 30, 2024
$ 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	$	1		$	87		$	1,696		$	2,363		$	4,147
Fair value	$	1		$	85		$	1,583		$	2,154		$	3,823
Weighted-average yield	2.08		%	2.53		%	1.29		%	2.05		%	1.75		%
Agency commercial MBS
Amortized cost	$	71		$	908		$	387		$	49		$	1,415
Fair value	$	70		$	854		$	332		$	40		$	1,296
Weighted-average yield	2.85		%	1.48		%	1.18		%	1.87		%	1.48		%
Agency CMOs
Amortized cost	$	—		$	4		$	34		$	1,356		$	1,394
Fair value	$	—		$	4		$	31		$	1,190		$	1,225
Weighted-average yield	—		%	2.27		%	1.51		%	1.86		%	1.85		%
U.S. Treasuries
Amortized cost	$	467		$	239		$	—		$	—		$	706
Fair value	$	466		$	238		$	—		$	—		$	704
Weighted-average yield	3.81		%	4.61		%	—		%	—		%	4.08		%
Other agency obligations
Amortized cost	$	257		$	272		$	28		$	8		$	565
Fair value	$	254		$	269		$	27		$	9		$	559
Weighted-average yield	2.70		%	3.70		%	2.42		%	3.07		%	3.17		%
Non-agency residential MBS
Amortized cost	$	—		$	—		$	—		$	553		$	553
Fair value	$	—		$	—		$	—		$	527		$	527
Weighted-average yield	—		%	—		%	—		%	4.35		%	4.35		%
Corporate bonds
Amortized cost	$	7		$	77		$	23		$	—		$	107
Fair value	$	7		$	76		$	23		$	—		$	106
Weighted-average yield	3.48		%	5.71		%	5.02		%	—		%	5.41		%
Other
Amortized cost	$	—		$	5		$	4		$	10		$	19
Fair value	$	—		$	5		$	5		$	10		$	20
Weighted-average yield	—		%	7.29		%	2.68		%	7.72		%	6.36		%
Total available-for-sale securities
Amortized cost	$	803		$	1,592		$	2,172		$	4,339		$	8,906
Fair value	$	798		$	1,531		$	2,001		$	3,930		$	8,260
Weighted-average yield	3.36		%	2.61		%	1.33		%	2.30		%	2.21		%

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	Fair value		Unrealized losses		Fair value		Unrealized losses		Fair value		Unrealized losses
September 30, 2024
Agency residential MBS	$	—	$	—	$	3,679	$	(327)	$	3,679	$	(327)
Agency commercial MBS	—		—		1,287		(119)		1,287		(119)
Agency CMOs	30		—		1,114		(170)		1,144		(170)
U.S. Treasuries	475		—		229		(2)		704		(2)
Other agency obligations	10		—		539		(6)		549		(6)
Non-agency residential MBS	—		—		417		(27)		417		(27)
Corporate bonds	—		—		42		(2)		42		(2)
Other	—		—		4		—		4		—
Total	$	515	$	—	$	7,311	$	(653)	$	7,826	$	(653)
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)
U.S. Treasuries	120		—		995		(21)		1,115		(21)
Other agency obligations	97		(1)		582		(30)		679		(31)
Non-agency residential MBS	62		(1)		401		(63)		463		(64)
Corporate bonds	13		—		78		(6)		91		(6)
Other	5		—		9		—		14		—
Total	$	373	$	(5)	$	8,617	$	(1,247)	$	8,990	$	(1,252)