Equity - Capped Calls (Details) - Call Option shares in Millions	9 Months Ended
	May 31, 2018 USD ($) shares
Option Indexed to Issuer's Equity [Line Items]
Treasury shares acquired from settlement of capped calls (in shares) | shares	9
Purchased options
Option Indexed to Issuer's Equity [Line Items]
Shares received upon settlement of capped calls | shares	9
Dollar value of shares received upon settlement of capped calls	$ 429,000,000
Purchased options | Minimum
Option Indexed to Issuer's Equity [Line Items]
Value at Expiration	0
Purchased options | Maximum
Option Indexed to Issuer's Equity [Line Items]
Value at Expiration	$ 98,000,000