Trade Accounts Receivable Securitization and Sale Programs (Details) ¥ in Millions	3 Months Ended		9 Months Ended
	May 31, 2017 USD ($)	May 31, 2016 USD ($)	May 31, 2017 USD ($)	May 31, 2016 USD ($)	May 31, 2017 CNY (¥)	May 31, 2017 USD ($)
Trade Accounts Receivable Sale Programs
Trade Accounts Receivable Securitization and Sale Program [Line Items]
Trade accounts receivable sold	$ 500,000,000	$ 700,000,000	$ 2,200,000,000	$ 3,000,000,000
Cash proceeds for the sale of trade accounts receivable	500,000,000	700,000,000	2,200,000,000	2,900,000,000
Pretax losses on sale of trade accounts receivable	(1,500,000)	(1,100,000)	$ (4,100,000)	(3,100,000)
Asset-Backed Securitization Programs
Trade Accounts Receivable Securitization and Sale Program [Line Items]
Percentage of trade accounts receivable sold to conduits by special purpose entities			100.00%
Trade accounts receivable sold	2,100,000,000	2,000,000,000	$ 6,600,000,000	5,800,000,000
Cash proceeds for the sale of trade accounts receivable	1,600,000,000	1,500,000,000	6,100,000,000	5,300,000,000
Cash proceeds from new transfers	0	0	0	3,000,000
Deferred purchases price receivable		517,300,000		517,300,000		$ 501,300,000
Pretax losses on sale of trade accounts receivable	$ 2,500,000	$ 1,300,000	$ 6,600,000	$ 3,500,000
North American Asset-Backed Securitization Program
Trade Accounts Receivable Securitization and Sale Program [Line Items]
Expiration date			Oct. 20, 2017
Maximum net cash proceeds available at any one time under asset-backed securitization program and sales program						200,000,000
Foreign Asset-Backed Securitization Program
Trade Accounts Receivable Securitization and Sale Program [Line Items]
Expiration date			May 01, 2018
Maximum net cash proceeds available at any one time under asset-backed securitization program and sales program						400,000,000
Foreign Asset-Backed Securitization Program | Before amendment
Trade Accounts Receivable Securitization and Sale Program [Line Items]
Maximum net cash proceeds available at any one time under asset-backed securitization program and sales program						275,000,000
Foreign Asset-Backed Securitization Program | After amendment
Trade Accounts Receivable Securitization and Sale Program [Line Items]
Maximum net cash proceeds available at any one time under asset-backed securitization program and sales program						400,000,000
650.0 Million Dollar Trade Accounts Receivable Sale Program
Trade Accounts Receivable Securitization and Sale Program [Line Items]
Expiration date			Aug. 31, 2017
Maximum net cash proceeds available at any one time under asset-backed securitization program and sales program						650,000,000
Minimum number of days notice required to cancel receivable sale agreements			15 days
150.0 Million Dollar Trade Accounts Receivable Sale Program
Trade Accounts Receivable Securitization and Sale Program [Line Items]
Expiration date			Aug. 31, 2017
150.0 Million Dollar Trade Accounts Receivable Sale Program | Trade Accounts Receivable Sale Programs
Trade Accounts Receivable Securitization and Sale Program [Line Items]
Maximum net cash proceeds available at any one time under asset-backed securitization program and sales program						150,000,000
800.0 Million CNY Trade Accounts Receivable Sale Program | Trade Accounts Receivable Sale Programs
Trade Accounts Receivable Securitization and Sale Program [Line Items]
Expiration date			Feb. 15, 2018
Maximum net cash proceeds available at any one time under asset-backed securitization program and sales program | ¥					¥ 800.0
100.0 Million Dollar Trade Accounts Receivable Sale Program
Trade Accounts Receivable Securitization and Sale Program [Line Items]
Expiration date			Oct. 31, 2017
100.0 Million Dollar Trade Accounts Receivable Sale Program | Trade Accounts Receivable Sale Programs
Trade Accounts Receivable Securitization and Sale Program [Line Items]
Maximum net cash proceeds available at any one time under asset-backed securitization program and sales program						$ 100,000,000
Minimum number of days notice required to cancel receivable sale agreements			15 days
Agreement extension date			Nov. 01, 2018
Minimum number of days notice required to not automatically extend receivable sale agreements			30 days