CONSOLIDATED STATEMENTS OF CHANGES IN EQUITY (UNAUDITED) (Parenthetical) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Mar. 31, 2024	Mar. 31, 2023	Mar. 31, 2024	Mar. 31, 2023	Sep. 30, 2023	Sep. 30, 2022
Dividends declared, quarterly, per share (in dollars per share)	$ 0.52	$ 0.45	$ 0.52	$ 0.45
Dividends paid, quarterly, per share (in dollars per share)	$ 0.52	$ 0.45	$ 0.52	$ 0.45
Preferred stock	$ 1,602		$ 1,602		$ 1,698
Series A preferred stock
Preferred stock	$ 385	$ 627	$ 385	$ 627	$ 456	$ 1,000