Trade Accounts Receivable Securitization and Sale Programs - Trade Accounts Receivable Sale Programs Key Terms (Details) - 9 months ended May 31, 2018	CNY (¥)	USD ($)
A
Trade Accounts Receivable Securitization and Sale Program [Line Items]
Maximum Amount of Net Cash Proceeds		$ 650,000,000
Notice period to cancel receivable sale agreements	15 days
B
Trade Accounts Receivable Securitization and Sale Program [Line Items]
Maximum Amount of Net Cash Proceeds		150,000,000
C
Trade Accounts Receivable Securitization and Sale Program [Line Items]
Maximum Amount of Net Cash Proceeds | ¥	¥ 800,000,000
D
Trade Accounts Receivable Securitization and Sale Program [Line Items]
Maximum Amount of Net Cash Proceeds		100,000,000
Notice period to cancel receivable sale agreements	30 days
E
Trade Accounts Receivable Securitization and Sale Program [Line Items]
Maximum Amount of Net Cash Proceeds		50,000,000
F
Trade Accounts Receivable Securitization and Sale Program [Line Items]
Maximum Amount of Net Cash Proceeds		150,000,000
Threshold period to cancel trade accounts receivable sale agreement before automatic extension	30 days
G
Trade Accounts Receivable Securitization and Sale Program [Line Items]
Maximum Amount of Net Cash Proceeds		$ 50,000,000
Notice period to cancel receivable sale agreements	15 days