CONDENSED CONSOLIDATED STATEMENTS OF SHAREHOLDERS' EQUITY (Parenthetical) - $ / shares	3 Months Ended		9 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Statement Of Stockholders Equity [Abstract]
Dividends declared on common stock (in dollars per share)	$ 0.5925	$ 0.5625	$ 1.7775	$ 1.6875