Performance Period for Performance RSUs

No definition available.

Name:	phii_PerformancePeriodForPerformanceRSUs
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Balance Type:	na
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- Definition

Represents the expense recognized during the period arising from equity-based compensation arrangements (for example, shares of stock, unit, stock options or other equity instruments) with employees, directors and certain consultants qualifying for treatment as employees.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 50
-Paragraph 1
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=109197908&loc=d3e5047-113901

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SAB Topic 14.F)
-URI http://asc.fasb.org/extlink&oid=115993241&loc=d3e301413-122809

Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (h)(1)(i)
-URI http://asc.fasb.org/extlink&oid=109197908&loc=d3e5070-113901

+ Details

Name:	us-gaap_AllocatedShareBasedCompensationExpense
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Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Aggregate cash paid by the entity during the period to settle equity instruments granted under equity-based payment arrangements.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (k)
-URI http://asc.fasb.org/extlink&oid=109197908&loc=d3e5070-113901

+ Details

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- References

No definition available.

+ Details

Name:	us-gaap_ShareBasedCompensationAbstract
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Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

The number of equity-based payment instruments, excluding stock (or unit) options, that were forfeited during the reporting period.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (c)(1)(iv)(3)
-URI http://asc.fasb.org/extlink&oid=109197908&loc=d3e5070-113901

+ Details

Name:	us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeitedInPeriod
Namespace Prefix:	us-gaap_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	duration

- Definition

The number of grants made during the period on other than stock (or unit) option plans (for example, phantom stock or unit plan, stock or unit appreciation rights plan, performance target plan).

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (c)(2)(iii)(1)
-URI http://asc.fasb.org/extlink&oid=109197908&loc=d3e5070-113901

+ Details

Name:	us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriod
Namespace Prefix:	us-gaap_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	duration

- Definition

Price of a single share of a number of saleable stocks of a company.

+ References

No definition available.

+ Details

Name:	us-gaap_SharePrice
Namespace Prefix:	us-gaap_
Data Type:	num:perShareItemType
Balance Type:	na
Period Type:	instant

- Details

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- Details

Name:	us-gaap_AwardTypeAxis=phii_TimeBasedAwardsMember
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Data Type:	na
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Period Type:

- Details

Name:	us-gaap_AwardTypeAxis=phii_PerformanceBasedAwardsMember
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Data Type:	na
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- Details

Name:	us-gaap_AwardDateAxis=phii_A2016GrantMember
Namespace Prefix:
Data Type:	na
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Stock-Based Compensation - Summary of Share Based Compensation Expense (Detail) - USD ($) $ / shares in Units, $ in Thousands		3 Months Ended		6 Months Ended
	Feb. 20, 2019	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Stock-based compensation expense:
Total stock-based compensation expense		$ 1,325	$ 813	$ 2,640	$ 2,132
Non Voting Performance Units [Member]
Stock-based compensation expense:
Performance period for performance RSUs	2 years
Share price (in USD per share)	$ 2.21
Cash settlement for performance awards	$ 800
Time-based Restricted Stock Units [Member]
Stock-based compensation expense:
Total stock-based compensation expense		845	$ 435	$ 1,685	$ 1,077
Grants to managerial employees			321,831	0	321,831
Performance-based Restricted Units [Member]
Stock-based compensation expense:
Total stock-based compensation expense		$ 480	$ 378	$ 955	$ 1,055
Grants to managerial employees			448,012	0	448,012
Performance-based Restricted Units [Member] \| 2016 Grant [Member]
Stock-based compensation expense:
Forfeited (shares)	667,238