AVAILABLE-FOR-SALE SECURITIES, Contractual Maturities (Details) - USD ($) $ in Millions	Jun. 30, 2020	Sep. 30, 2019
Carrying value
Total	$ 5,630	$ 3,093
RJ Bank
Amortized cost
Within one year	12
After one but within five years	211
After five but within ten years	1,508
After ten years	3,781
Cost basis	5,512	3,065
Carrying value
Within one year	12
After one but within five years	218
After five but within ten years	1,552
After ten years	3,848
Total	$ 5,630	3,093
Weighted-average yield
Within one year (in hundredths)	1.99%
After one but within five years (in hundredths)	2.29%
After five but within ten years (in hundredths)	2.05%
After ten years (in hundredths)	1.82%
Total (in hundredths)	1.90%
RJ Bank | Agency residential MBS
Amortized cost
Within one year	$ 0
After one but within five years	27
After five but within ten years	1,130
After ten years	1,738
Cost basis	2,895	1,555
Carrying value
Within one year	0
After one but within five years	28
After five but within ten years	1,160
After ten years	1,775
Total	2,963	1,574
RJ Bank | Agency commercial MBS
Amortized cost
Within one year	12
After one but within five years	170
After five but within ten years	285
After ten years	103
Cost basis	570	305
Carrying value
Within one year	12
After one but within five years	175
After five but within ten years	298
After ten years	105
Total	590	310
RJ Bank | Agency CMOs
Amortized cost
Within one year	0
After one but within five years	11
After five but within ten years	81
After ten years	1,940
Cost basis	2,032	1,195
Carrying value
Within one year	0
After one but within five years	11
After five but within ten years	82
After ten years	1,968
Total	2,061	1,199
RJ Bank | Other securities
Amortized cost
Within one year	0
After one but within five years	3
After five but within ten years	12
After ten years	0
Cost basis	15	10
Carrying value
Within one year	0
After one but within five years	4
After five but within ten years	12
After ten years	0
Total	$ 16	$ 10