XML 52 R42.htm IDEA: XBRL DOCUMENT
v3.19.2

SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES, RISKS AND UNCERTAINTIES - Self-Insurance (Details) $ in Millions | 9 Months Ended
--- | ---
Jun. 30, 2019 USD ($)
Minimum |
Unusual Risk or Uncertainty [Line Items] |
Insurance coverage deductibles range for claims which occur outside or inside the United States | $ 1
Maximum |
Unusual Risk or Uncertainty [Line Items] |
Insurance coverage deductibles range for claims which occur outside or inside the United States | $ 5

X
- Definition Represents the deductible amounts of claims that are covered by insurance. + References No definition available. + Details
Name: | hp_SelfInsuranceCoverageDeductiblesRangeForClaimsIncurred
Namespace Prefix: | hp_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition 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. + References No definition available. + Details
Name: | us-gaap_UnusualRiskOrUncertaintyLineItems
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Details
Name: | srt_RangeAxis=srt_MinimumMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | srt_RangeAxis=srt_MaximumMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |