XML 78 R68.htm IDEA: XBRL DOCUMENT v3.10.0.1

Guarantor and Non-Guarantor Financial Information - Debt (Details) - USD ($) $ in Millions	1 Months Ended
	Mar. 31, 2015	Jun. 30, 2018	Mar. 19, 2015
Financial Information
Percentage ownership of subsidiary	100.00%
Unsecured senior notes issued March 19, 2015
Financial Information
Debt issued		$ 500.0	$ 500.0
Issuer Subsidiary | Unsecured senior notes issued March 19, 2015
Financial Information
Debt issued	$ 500.0

X

- Definition

NA

+ References

No definition available.

+ Details

Name:	hp_ConsolidatedCondensedFinancialInformationAbstract
Namespace Prefix:	hp_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

X

- Definition

Face (par) amount of debt instrument at time of issuance.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 835
-SubTopic 30
-Section 55
-Paragraph 8
-URI http://asc.fasb.org/extlink&oid=64930739&loc=d3e28878-108400

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 835
-SubTopic 30
-Section 45
-Paragraph 2
-URI http://asc.fasb.org/extlink&oid=64930785&loc=d3e28551-108399

+ Details

Name:	us-gaap_DebtInstrumentFaceAmount
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

X

- Definition

Percentage of subsidiary's or equity method investee's stock owned by parent immediately after all stock transactions.

+ References

No definition available.

+ Details

Name:	us-gaap_SubsidiaryOrEquityMethodInvesteeCumulativePercentageOwnershipAfterAllTransactions
Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

X

- Details

Name:	us-gaap_DebtInstrumentAxis=hp_UnsecuredSeniorNotesIssued2015Member
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	us-gaap_ConsolidatedEntitiesAxis=us-gaap_SubsidiaryIssuerMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: