SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES, RISKS AND UNCERTAINTIES - International Drilling Operations (Details)	12 Months Ended
Sep. 30, 2018
Risk or uncertainty
Period for which cumulative inflation rates used for considering country as highly inflationary	3 years
Minimum
Risk or uncertainty
Cumulative inflation rate before a country is considered highly inflationary (as a percent)	100.00%

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

No definition available.

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