Stockholders' Equity and Earnings per Share - Additional Information (Details) - USD ($) $ / shares in Units, shares in Millions		1 Months Ended		3 Months Ended		9 Months Ended
	Dec. 31, 2019	Jan. 31, 2020	Sep. 30, 2019	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019	May 31, 2020	Oct. 31, 2018
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Increase in quarterly cash dividend (as a percentage)		5.00%
Dividends (in dollars per share)	$ 0.40	$ 0.42		$ 0.42	$ 0.40	$ 1.24	$ 1.20
Repurchase of common stock				$ 13,297,000	$ 174,912,000	$ 405,692,000	$ 498,886,000
Antidilutive securities excluded from earnings per share computation (shares)				2.5	5.3	3.6	4.8
October 2018 Share Repurchase Program
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Authorized amount under share repurchase program									$ 1,000,000,000.0
Repurchase of common stock (shares)						4.9
Repurchase of common stock						$ 405,600,000
Cash settled purchases			$ 14,800,000
Availability remaining under program				$ 55,500,000		$ 55,500,000
May 2020 Share Repurchase Program
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Authorized amount under share repurchase program								$ 500,000,000