XML 66 R56.htm IDEA: XBRL DOCUMENT
v3.8.0.1

Commitments and Contingencies (Details) $ in Millions | Mar. 31, 2018 USD ($)
--- | ---
Commitments and Contingencies |
Purchase orders outstanding for drilling equipment | $ 70.3
Contingencies |
Gain contingencies recognized in consolidated financial statements | $ 0.0

X
- References No definition available. + Details
Name: | hp_ContingenciesAbstract
Namespace Prefix: | hp_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

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

X
- Definition Amount of gain recognized in the period that had been disclosed in prior periods as a contingent gain. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 450 -SubTopic 30 -Section 50 -Paragraph 1 -URI http://asc.fasb.org/extlink&oid=6397426&loc=d3e17499-108355 + Details
Name: | us-gaap_FormerGainContingencyRecognizedInCurrentPeriod
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Minimum amount of purchase arrangement in which the entity has agreed to expend funds to procure goods or services from a supplier. + References No definition available. + Details
Name: | us-gaap_PurchaseObligation
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant