v3.8.0.1

Segment Information - Schedule of Provisions for Contractual Discounts and Estimated Uncompensated Care as a Percentage of Gross Segment Billings (Detail) - Air Medical [Member] | 3 Months Ended | 9 Months Ended
--- | --- | ---
Sep. 30, 2017 | Sep. 30, 2016 | Sep. 30, 2017 | Sep. 30, 2016
Provisions For Contractual Discounts And Estimated Uncompensated Care [Line Items] |  |  |  |
Provision for contractual discounts | 65.00% | 65.00% | 66.00% | 67.00%
Provision for uncompensated care | 6.00% | 9.00% | 7.00% | 6.00%

X
- Definition Provision for contractual discounts. + References No definition available. + Details
Name: | phii_ProvisionPercentageContractualDiscounts
Namespace Prefix: | phii_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | duration

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

X
- Definition Provisions For Contractual Discounts And Estimated Uncompensated Care [Line Items] + References No definition available. + Details
Name: | phii_ProvisionsForContractualDiscountsAndEstimatedUncompensatedCareLineItems
Namespace Prefix: | phii_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

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