v3.8.0.1

Revenue Recognition and Valuation Accounts - Schedule of Allowance for Contractual Discounts and Estimated Uncompensated Care as a Percentage of Gross Segment Accounts Receivable (Detail) - Air Medical [Member] - Trade Accounts Receivable [Member] | Sep. 30, 2017 | Dec. 31, 2016
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Valuation and Qualifying Accounts Disclosure [Line Items] |  |
Allowance for Contractual Discounts | 58.00% | 56.00%
Allowance for Uncompensated Care | 21.00% | 23.00%

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- Definition Allowance for contractual discounts expressed as a percentage of gross segment receivables + References No definition available. + Details
Name: | phii_AllowancePercentageContractualDiscounts
Namespace Prefix: | phii_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | instant

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- Definition Percentage of provision for uncompensated care. + References No definition available. + Details
Name: | phii_AllowancePercentageUncompensatedCare
Namespace Prefix: | phii_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | instant

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- 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_ValuationAndQualifyingAccountsDisclosureLineItems
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

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- Details
Name: | us-gaap_StatementBusinessSegmentsAxis=phii_AirMedicalMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

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- Details
Name: | us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis=us-gaap_TradeAccountsReceivableMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |