Stockholders' Equity (Common Stock Outstanding) (Details) - USD ($)	3 Months Ended		6 Months Ended
	Feb. 28, 2022	Feb. 28, 2021	Feb. 28, 2022	Feb. 28, 2021	Jul. 31, 2021
Common stock outstanding:
Common stock outstanding, beginning balances (in shares)			144,496,077
Common stock outstanding, ending balance (in shares)	142,392,135		142,392,135
2022 Share Repurchase Program
Common stock outstanding:
Share repurchase program, amount authorized					$ 1,000,000,000
Number of shares repurchased (in shares)			5,100,000
Value of shares repurchased			$ 314,000,000
Share repurchase program, remaining amount available	$ 686,000,000		$ 686,000,000
Common stock
Common stock outstanding:
Common stock outstanding, beginning balances (in shares)	144,166,009	150,471,570	144,496,077	150,330,358
Shares issued under employee stock purchase plan (in shares)	520,483	771,548	520,483	771,548
Vesting of restricted stock (in shares)	28,243	24,054	2,453,715	2,241,136
Purchases of treasury stock under employee stock plans (in shares)	(9,719)	(8,873)	(700,274)	(610,279)
Treasury shares purchased (in shares)	(2,312,881)	(1,891,798)	(4,377,866)	(3,366,262)
Common stock outstanding, ending balance (in shares)	142,392,135	149,366,501	142,392,135	149,366,501