AVAILABLE-FOR-SALE SECURITIES (Tables)

6 Months Ended

Mar. 31, 2022

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.

$ in millions	Cost basis		Gross unrealized gains		Gross unrealized losses		Fair value
March 31, 2022
Agency residential MBS	$	5,629	$	4	$	(276)	$	5,357
Agency commercial MBS	1,414		—		(114)		1,300
Agency CMOs	1,757		—		(119)		1,638
U.S. Treasuries	214		—		(1)		213
Other agency obligations	313		—		(6)		307
Total available-for-sale securities	$	9,327	$	4	$	(516)	$	8,815
September 30, 2021
Agency residential MBS	$	5,168	$	46	$	(25)	$	5,189
Agency commercial MBS	1,285		7		(28)		1,264
Agency CMOs	1,854		9		(16)		1,847
U.S. Treasuries	15		—		—		15
Total available-for-sale securities	$	8,322	$	62	$	(69)	$	8,315

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.  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 March 31, 2022, the weighted-average life of our available-for-sale securities portfolio was approximately four years.

	March 31, 2022
$ 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	$	—		$	130		$	2,746		$	2,753		$	5,629
Carrying value	$	—		$	130		$	2,628		$	2,599		$	5,357
Agency commercial MBS
Amortized cost	$	26		$	427		$	888		$	73		$	1,414
Carrying value	$	26		$	406		$	800		$	68		$	1,300
Agency CMOs
Amortized cost	$	—		$	7		$	39		$	1,711		$	1,757
Carrying value	$	—		$	7		$	38		$	1,593		$	1,638
U.S. Treasuries
Amortized cost	$	—		$	211		$	3		$	—		$	214
Carrying value	$	—		$	210		$	3		$	—		$	213
Other agency obligations
Amortized cost	$	—		$	313		$	—		$	—		$	313
Carrying value	$	—		$	307		$	—		$	—		$	307
Total available-for-sale securities
Amortized cost	$	26		$	1,088		$	3,676		$	4,537		$	9,327
Carrying value	$	26		$	1,060		$	3,469		$	4,260		$	8,815
Weighted-average yield	2.23		%	1.67		%	1.18		%	1.30		%	1.30		%

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
March 31, 2022
Agency residential MBS	$	3,893	$	(193)	$	1,117	$	(83)	$	5,010	$	(276)
Agency commercial MBS	650		(36)		635		(78)		1,285		(114)
Agency CMOs	1,172		(76)		443		(43)		1,615		(119)
U.S. Treasuries	168		(1)		—		—		168		(1)
Other agency obligations	307		(6)		—		—		307		(6)
Total	$	6,190	$	(312)	$	2,195	$	(204)	$	8,385	$	(516)
September 30, 2021
Agency residential MBS	$	3,155	$	(25)	$	18	$	—	$	3,173	$	(25)
Agency commercial MBS	645		(13)		353		(15)		998		(28)
Agency CMOs	918		(12)		231		(4)		1,149		(16)
U.S. Treasuries	3		—		—		—		3		—
Total	$	4,721	$	(50)	$	602	$	(19)	$	5,323	$	(69)