v3.5.0.2

Investment in Variable Interest Entity - Additional Information (Detail) - USD ($) $ in Millions | 3 Months Ended | 9 Months Ended |
--- | --- | --- | ---
Sep. 30, 2016 | Sep. 30, 2015 | Sep. 30, 2016 | Sep. 30, 2015 | Dec. 30, 2015
Variable Interest Entity [Line Items] |  |  |  |  |
Earnings (loss) in equity of unconsolidated affiliate | $ (0.2) | $ (0.1) | $ (0.3) | $ (0.2) |
Trade receivables | 0.0 |  | 0.0 |  |
Other assets | $ 0.9 |  | $ 0.9 |  | $ 0.0
PHIC's date of incorporation |  |  | May 26, 2011 |  |
PHI Century Limited [Member] |  |  |  |  |
Variable Interest Entity [Line Items] |  |  |  |  |
Investment in the common stock |  |  | 49.00% |  |
Allowance for Trade Receivables [Member] |  |  |  |  |
Variable Interest Entity [Line Items] |  |  |  |  |
Allowance for bad debts against trade receivables |  |  |  |  | $ 1.5

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- Definition Allowance for bad debts against VIE trade receivables. + References No definition available. + Details
Name: | phii_AllowanceForBadDebtsAgainstVIETradeReceivables
Namespace Prefix: | phii_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

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- Definition Equity In Earnings (Loss) Of Unconsolidated Affiliates + References No definition available. + Details
Name: | phii_EquityInEarningsLossOfUnconsolidatedAffiliates
Namespace Prefix: | phii_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

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- Definition Investment in variable interest entity. + References No definition available. + Details
Name: | phii_InvestmentInVariableInterestEntity
Namespace Prefix: | phii_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

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- Definition Trade receivables. + References No definition available. + Details
Name: | phii_TradeReceivables
Namespace Prefix: | phii_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
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_VariableInterestEntityLineItems
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

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- Definition Percentage of the Variable Interest Entity's (VIE) voting interest owned by (or beneficial interest in) the reporting entity (directly or indirectly). + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 810 -SubTopic 10 -Section 50 -Paragraph 5A -Subparagraph (d) -URI http://asc.fasb.org/extlink&oid=64801991&loc=SL6759159-111685 + Details
Name: | us-gaap_VariableInterestEntityOwnershipPercentage
Namespace Prefix: | us-gaap_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | duration

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- Definition Date the relationship between reporting entity and the Variable Interest Entity (VIE) began, in CCYY-MM-DD format. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 810 -SubTopic 10 -Section 50 -Paragraph 6 -Subparagraph b -URI http://asc.fasb.org/extlink&oid=64801991&loc=d3e5747-111685 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 810 -SubTopic 10 -Section 50 -Paragraph 5A -Subparagraph (d) -URI http://asc.fasb.org/extlink&oid=64801991&loc=SL6759159-111685 + Details
Name: | us-gaap_VariableInterestEntityQualitativeOrQuantitativeInformationDateInvolvementBegan1
Namespace Prefix: | us-gaap_
Data Type: | xbrli:dateItemType
Balance Type: | na
Period Type: | duration

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- Details
Name: | us-gaap_VariableInterestEntitiesByClassificationOfEntityAxis=phii_PhiCenturyLimitedMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

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- Details
Name: | us-gaap_ValuationAllowancesAndReservesTypeAxis=us-gaap_AllowanceForTradeReceivablesMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |