PHI (PHIG) 10-Q 3 Nov 17 2017 Q3 Quarterly report Financial data

Document and Entity Information

Document and Entity Information - shares	9 Months Ended
	Sep. 30, 2017	Oct. 31, 2017
Document Information [Line Items]
Document Type	10-Q
Amendment Flag	false
Document Period End Date	Sep. 30, 2017
Document Fiscal Year Focus	2,017
Document Fiscal Period Focus	Q3
Trading Symbol	PHII
Entity Registrant Name	PHI INC
Entity Central Index Key	350,403
Current Fiscal Year End Date	--12-31
Entity Filer Category	Accelerated Filer
Voting Common Stock [Member]
Document Information [Line Items]
Entity Common Stock, Shares Outstanding		2,905,757
Non-Voting Common Stock [Member]
Document Information [Line Items]
Entity Common Stock, Shares Outstanding		12,893,895

Condensed Consolidated Balance

Condensed Consolidated Balance Sheets (Unaudited) - USD ($) $ in Thousands	Sep. 30, 2017	Dec. 31, 2016
Current Assets:
Cash	$ 2,991	$ 2,596
Short-term investments	204,036	289,806
Accounts receivable – net
Trade	140,434	128,662
Other	12,303	9,603
Inventories of spare parts – net	79,245	70,402
Prepaid expenses	12,006	9,259
Deferred income taxes	10,798	10,798
Income taxes receivable	509	540
Total current assets	462,322	521,666
Property and equipment – net	910,327	903,977
Restricted cash and investments	12,396	13,038
Other assets	9,032	9,759
Total assets	1,394,077	1,448,440
Current Liabilities:
Accounts payable	30,607	28,704
Accrued and other current liabilities	33,703	28,346
Total current liabilities	64,310	57,050
Long-term debt:
Revolving credit facility	100,000	134,000
Senior Notes issued March 17, 2014, net of debt issuance costs of $1,818 and $2,753, respectively	498,182	497,247
Deferred income taxes	141,420	151,713
Other long-term liabilities	8,104	8,652
Commitments and contingencies (Note 9)
Shareholders’ Equity:
Additional paid-in capital	307,054	304,246
Accumulated other comprehensive loss	(244)	(478)
Retained earnings	273,671	294,441
Total shareholders’ equity	582,061	599,778
Total liabilities and shareholders’ equity	1,394,077	1,448,440
Voting Common Stock [Member]
Shareholders’ Equity:
Common stock	291	291
Non-Voting Common Stock [Member]
Shareholders’ Equity:
Common stock	1,289	1,278
Total shareholders’ equity	$ 1,289	$ 1,278

Condensed Consolidated Balance3

Condensed Consolidated Balance Sheets (Unaudited) (Parenthetical) - USD ($) $ in Thousands	Sep. 30, 2017	Dec. 31, 2016
Debt issuance costs	$ 1,818	$ 2,753
Voting Common Stock [Member]
Common stock, par value (in USD per share)	$ 0.10	$ 0.10
Common stock, shares authorized (shares)	12,500,000	12,500,000
Common stock, shares issued (shares)	2,905,757	2,905,757
Common stock, shares outstanding (shares)	2,905,757	2,905,757
Non-Voting Common Stock [Member]
Common stock, par value (in USD per share)	$ 0.10	$ 0.10
Common stock, shares authorized (shares)	37,500,000	37,500,000
Common stock, shares issued (shares)	12,893,895	12,779,646
Common stock, shares outstanding (shares)	12,893,895	12,779,646

Condensed Consolidated Statemen

Condensed Consolidated Statements of Operations (Unaudited) - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Income Statement [Abstract]
Operating revenues, net	$ 150,167	$ 158,093	$ 431,209	$ 489,245
Expenses:
Direct expenses	136,786	144,938	400,250	449,909
Selling, general and administrative expenses	11,401	13,381	38,691	36,832
Total operating expenses	148,187	158,319	438,941	486,741
Gain (loss) on disposal of assets	(4)	85	3	(3,854)
Equity in (earnings) loss of unconsolidated affiliates, net	(438)	198	1,556	274
Operating income (loss)	2,422	(509)	(9,291)	6,084
Interest expense	8,027	7,719	24,305	22,792
Other income – net	(706)	(462)	(2,474)	(1,571)
Total expenses	7,321	7,257	21,831	21,221
Loss before income taxes	(4,899)	(7,766)	(31,122)	(15,137)
Income tax benefit	(1,622)	(2,799)	(9,324)	(5,515)
Net loss	$ (3,277)	$ (4,967)	$ (21,798)	$ (9,622)
Weighted average shares outstanding:
Basic (shares)	15,799	15,683	15,750	15,655
Diluted (shares)	15,799	15,683	15,750	15,655
Net loss per share:
Basic (in USD per share)	$ (0.21)	$ (0.32)	$ (1.38)	$ (0.61)
Diluted (in USD per share)	$ (0.21)	$ (0.32)	$ (1.38)	$ (0.61)

Condensed Consolidated Stateme5

Condensed Consolidated Statements of Comprehensive Income (Loss) (Unaudited) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Statement of Comprehensive Income [Abstract]
Net (loss) earnings	$ (3,277)	$ (4,967)	$ (21,798)	$ (9,622)
Unrealized gain (loss) on short-term investments	41	(494)	370	523
Changes in pension plan assets and benefit obligations	(24)	1	(2)	3
Tax effect of the above-listed adjustments	(8)	178	(134)	(229)
Total comprehensive (loss) income	$ (3,268)	$ (5,282)	$ (21,564)	$ (9,325)

Condensed Consolidated Stateme6

Condensed Consolidated Statements of Shareholders' Equity (Unaudited) - USD ($) shares in Thousands, $ in Thousands	Total	Non-Voting Common Stock [Member]	Voting Common Stock [Member]	Additional Paid-in Capital [Member]	Accumulated Other Comprehensive (Loss) Income [Member]	Retained Earnings [Member]
Balance at Dec. 31, 2015	$ 626,998	$ 1,269	$ 291	$ 304,884	$ (567)	$ 321,121
Balance, Shares at Dec. 31, 2015		12,685	2,906
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net loss	(9,622)					(9,622)
Unrealized gain on short-term investments	294				294
Changes in pension plan assets and benefit obligations	2				2
Amortization of unearned stock-based compensation	4,334			4,334
Issuance of non-voting common stock (upon vesting of restricted stock units)	12	$ 12
Issuance of non-voting common stock (upon vesting of restricted stock units), shares		128
Cancellation of restricted non-voting stock units for tax withholdings on vested shares	(531)	$ (3)		(528)
Cancellation of restricted non-voting stock units for tax withholdings on vested shares, Shares		(28)
Retirement of treasury stock, shares		(8)
Balance at Sep. 30, 2016	621,487	$ 1,278	$ 291	308,690	(271)	311,499
Balance, Shares at Sep. 30, 2016		12,777	2,906
Balance at Dec. 31, 2016	599,778	$ 1,278	$ 291	304,246	(478)	294,441
Balance, Shares at Dec. 31, 2016		12,779	2,906
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net loss	(21,798)					(21,798)
Unrealized gain on short-term investments	235				235
Changes in pension plan assets and benefit obligations	(1)				(1)
Amortization of unearned stock-based compensation	3,074			3,074
Issuance of non-voting common stock (upon vesting of restricted stock units)	3	$ 13		(10)
Issuance of non-voting common stock (upon vesting of restricted stock units), shares		136
Cancellation of restricted non-voting stock units for tax withholdings on vested shares	(258)	$ (2)		(256)
Cancellation of restricted non-voting stock units for tax withholdings on vested shares, Shares		(22)
Cumulative effect adjustment of unrecognized tax benefits	1,028					1,028
Balance at Sep. 30, 2017	$ 582,061	$ 1,289	$ 291	$ 307,054	$ (244)	$ 273,671
Balance, Shares at Sep. 30, 2017		12,893	2,906

Condensed Consolidated Stateme7

Condensed Consolidated Statements of Cash Flows (Unaudited) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016
Operating activities:
Net loss	$ (21,798)	$ (9,622)
Adjustments to reconcile net loss to net cash provided by operating activities:
Depreciation and amortization	50,593	53,054
Deferred income taxes	(9,416)	(6,775)
Loss (gain) on asset dispositions	3	(3,854)
Equity in loss of unconsolidated affiliate, net	1,556	274
Inventory valuation reserves	(3)	3,766
Changes in operating assets and liabilities	(22,803)	(43,991)
Net cash (used in) provided by operating activities	(1,868)	(7,148)
Investing activities:
Purchase of property and equipment	(49,227)	(74,950)
Proceeds from asset dispositions	21	13,233
Purchase of short-term investments	(268,525)	(263,204)
Proceeds from sale of short-term investments	354,250	259,322
Payment of deposits on aircraft	0	(197)
Loan to unconsolidated affiliate	0	(1,200)
Net cash provided by (used in) investing activities	36,519	(66,996)
Financing activities:
Proceeds from line of credit	99,150	213,900
Payments on line of credit	(133,150)	(139,000)
Repurchase of common stock	(256)	(524)
Net cash (used in) provided by financing activities	(34,256)	74,376
Decrease in cash	395	232
Cash, beginning of period	2,596	2,407
Cash, end of period	2,991	2,639
Cash paid during the period for:
Interest	29,536	28,258
Income taxes	1,213	2,856
Noncash investing activities:
Other current liabilities and accrued payables related to purchase of property and equipment	$ 21	$ 3,717

Basis of Presentation

Basis of Presentation	9 Months Ended
	Sep. 30, 2017
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Basis of Presentation	BASIS OF PRESENTATION The accompanying unaudited condensed consolidated financial statements include the accounts of PHI, Inc. and its subsidiaries (“PHI” or the “Company” or “we” or “our”). In the opinion of management, these condensed consolidated financial statements reflect all adjustments, consisting of only normal, recurring adjustments, necessary to present fairly the financial results for the interim periods presented. These condensed consolidated financial statements should be read in conjunction with the consolidated financial statements and the accompanying notes contained in the Company’s Annual Report on Form 10-K for the year ended December 31, 2016 . Our financial results, particularly as they relate to our Oil and Gas segment, are influenced by seasonal fluctuations as discussed in the Company’s Annual Report on Form 10-K for the year ended December 31, 2016 . For this and other reasons, the results of operations for interim periods are not necessarily indicative of the operating results that may be expected for a full fiscal year. Recently Adopted Accounting Pronouncements - Effective January 1, 2017, we adopted Accounting Standards Update (“ASU”) 2016-09, Compensation - Stock Compensation (Topic 718): Improvements to Employee Share-Based Payment Accounting, which was issued by the Financial Accounting Standards Board (“FASB”) in March 2016 . This new standard requires that excess tax benefits and deficiencies resulting from stock-based compensation awards vesting and exercises be recognized in the income statement. Previously, these amounts were recognized in additional paid-in capital. As a result, during the first quarter of 2017 we recorded a cumulative-effect adjustment of $1.0 million increasing retained earnings and decreasing deferred tax liability on our balance sheet dated September 30, 2017 . Accordingly, we recorded income tax expense of $1.6 million in our consolidated statement of income for the nine months ended September 30, 2017 , in recognition of excess tax deficiencies related to equity compensation. Under this new standard, the corresponding cash flows are now reflected in cash provided by operating activities instead of financing activities, as was previously required. ASU 2016-09 also allows an employer with a statutory income tax withholding obligation to withhold shares with a fair value up to the amount of tax owed using the maximum statutory tax rate in the employee’s applicable jurisdiction. We have elected to continue to withhold the minimum statutory withholding obligation for outstanding awards. We have also elected to continue to estimate equity award forfeitures expected to occur to determine the amount of compensation cost to be recognized in each period. New Accounting Pronouncements - In May 2014, the FASB issued Accounting Standards Update ASU 2014-09, Revenue from Contracts with Customers , which provides a single comprehensive model for entities to use in accounting for revenue arising from contracts with customers. Entities can transition to the standard either retrospectively or as a cumulative effect adjustment as of the date of adoption. The new standard will be effective for the Company beginning on January 1, 2018. Revenues from our Oil and Gas segment and Air Medical segment hospital contracts are primarily comprised of a fixed monthly fee for a particular model of aircraft, plus a variable component based on flight time. Under the independent provider programs of our Air Medical segment, our revenues are based on a flat rate plus a variable charge per patient-loaded mile, and are recorded net of contractual allowances. We also generate revenue on a cost-plus basis in our Technical Services segment. Based on our initial assessment, we do not expect the adoption of this ASU to have a material impact on our condensed consolidated financial statements. Remaining implementation matters include establishing new policies, procedures, and controls and quantifying any adoption date adjustments. We plan to adopt this standard on January 1, 2018 utilizing the modified retrospective method. In February 2016, the FASB issued ASU 2016-02, Leases , which replaces the existing guidance on leasing transactions in ASC 840 to require recognition of the assets and liabilities for the rights and obligations created by those leases on the balance sheet. We are currently evaluating the effects of this standard, and expect the adoption of this standard will result in a material change to our consolidated assets and liabilities based on our lease portfolio as of September 30, 2017 . We plan to adopt this standard beginning January 1, 2019. In October 2016, the FASB issued ASU 2016-16, Income Taxes (Topic 740): Intra-Entity Transfers of Assets Other than Inventory , which will require an entity to recognize the income tax consequences of an intra-entity transfer of an asset, other than inventory, when the transfer occurs. ASU 2016-16 is effective for annual periods beginning after December 15, 2017, including interim periods within those annual periods. The effects of this standard on our financial position, results of operations, and cash flows are not yet known. We plan to adopt this standard beginning January 1, 2018. In January 2017, the FASB issued ASU 2017-01, Business Combinations (Topic 805): Clarifying the Definition of a Business . ASU 2017-01 clarifies the definition of a business and requires that an entity apply certain criteria in order to determine when a set of assets and activities qualifies as a business. The adoption of this standard is expected to result in fewer acquisitions of properties qualifying as acquisitions of businesses and, accordingly, acquisition costs for those acquisitions that do not qualify as businesses will be capitalized rather than expensed. This standard is effective for fiscal years beginning after December 15, 2017, and interim periods within those fiscal years, and should be applied on a prospective basis. Early adoption is permitted. The effects of this standard on our financial position, results of operations, and cash flows are not yet known. We plan to adopt this standard beginning January 1, 2018. In January 2017, the FASB issued ASU 2017-04, Intangibles-Goodwill and Other (Topic 350): Simplifying the Test for Goodwill Impairment . ASU 2017-04 simplifies the current two-step goodwill impairment test by eliminating the second step of the test. The new standard requires a one-step impairment test in which an entity compares the fair value of a reporting unit with its carrying amount and recognizes an impairment charge for the amount by which the carrying amount exceeds the reporting unit’s fair value, if any. This standard is effective for fiscal years beginning after December 15, 2019, and interim periods within those fiscal years, and should be applied on a prospective basis. Early adoption is permitted for interim or annual goodwill impairment tests performed on testing dates after January 1, 2017. We do not expect this ASU to have a material impact on our consolidated financial statements.

Investments

Investments	9 Months Ended
	Sep. 30, 2017
Investments, Debt and Equity Securities [Abstract]
Investments	INVESTMENTS We classify all of our short-term investments as available-for-sale. We carry these at fair value and report unrealized gains and losses, net of taxes, in Accumulated other comprehensive loss, which is a separate component of shareholders’ equity in our Condensed Consolidated Balance Sheets. These unrealized gains and losses are also reflected in our Condensed Consolidated Statements of Comprehensive Income and Condensed Consolidated Statements of Shareholders’ Equity. We determine cost, gains, and losses using the specific identification method. Investments consisted of the following as of September 30, 2017 : Cost Basis Unrealized Unrealized Fair (Thousands of dollars) Investments: Money market mutual funds $ 5,278 $ — $ — $ 5,278 Commercial paper 9,423 — (10 ) 9,413 U.S. Government agencies 13,505 — (14 ) 13,491 Corporate bonds and notes 188,515 3 (283 ) 188,235 Subtotal 216,721 3 (307 ) 216,417 Deferred compensation plan assets included in other assets 2,630 — — 2,630 Total $ 219,351 $ 3 $ (307 ) $ 219,047 Investments consisted of the following as of December 31, 2016 : Cost Basis Unrealized Gains Unrealized Losses Fair Value (Thousands of dollars) Investments: Money market mutual funds $ 18,118 $ — $ — $ 18,118 Commercial paper 27,906 — (39 ) 27,867 U.S. government agencies 13,295 — (32 ) 13,263 Corporate bonds and notes 244,202 2 (622 ) 243,582 Subtotal 303,521 2 (693 ) 302,830 Deferred compensation plan assets included in other assets 2,394 — — 2,394 Total $ 305,915 $ 2 $ (693 ) $ 305,224 At September 30, 2017 and December 31, 2016 , we classified $12.4 million and $ 13.0 million respectively, of our aggregate investments as long-term investments and recorded them in our Condensed Consolidated Balance Sheets as Restricted cash and investments, as they are securing outstanding letters of credit with maturities beyond one year and a bond relating to foreign operations. The following table presents the cost and fair value of our debt investments based on maturities as of: September 30, 2017 December 31, 2016 Amortized Fair Amortized Fair (Thousands of dollars) Due in one year or less $ 133,633 $ 133,481 $ 184,587 $ 184,334 Due within two years 77,810 77,658 100,816 100,378 Total $ 211,443 $ 211,139 $ 285,403 $ 284,712 The following table presents the average coupon rate percentage and the average days to maturity of our debt investments as of: September 30, 2017 December 31, 2016 Average Average Average Average Commercial paper 1.236 228 1.001 184 U.S. Government agencies 1.213 325 0.970 400 Corporate bonds and notes 1.715 295 1.745 318 The following table presents the fair value and unrealized losses related to our investments that have been in a continuous unrealized loss position for less than twelve months as of: September 30, 2017 December 31, 2016 Fair Value Unrealized Fair Value Unrealized (Thousands of dollars) Commercial paper $ 9,413 $ (10 ) $ 27,867 $ (39 ) U.S. Government agencies 9,495 (10 ) 13,263 (32 ) Corporate bonds and notes 102,767 (173 ) 210,836 (602 ) Total $ 121,675 $ (193 ) $ 251,966 $ (673 ) The following table presents the fair value and unrealized losses related to our investments that have been in a continuous unrealized loss position for more than twelve months as of: September 30, 2017 December 31, 2016 Fair Value Unrealized Fair Value Unrealized (Thousands of dollars) U.S. Government agencies $ 3,996 $ (4 ) $ — $ — Corporate bonds and notes 77,187 (110 ) 24,196 (20 ) Total $ 81,183 $ (114 ) $ 24,196 $ (20 ) From time to time over the periods covered in our financial statements included herein (and as illustrated in the foregoing tables), our investments have experienced net unrealized losses. We consider these declines in market value to be due to customary market fluctuations, and we do not plan to sell these investments prior to maturity. For these reasons, we do not consider any of our investments to be other than temporarily impaired at September 30, 2017 or December 31, 2016 . We have also determined that we did not have any other than temporary impairments relating to credit losses on debt securities for the quarter ended September 30, 2017 . For additional information regarding our criteria for making these assessments, see Note 2 to the financial statements included in our Annual Report on Form 10-K for the year ended December 31, 2016 .

Revenue Recognition and Valuati

Revenue Recognition and Valuation Accounts	9 Months Ended
	Sep. 30, 2017
Revenue Recognition And Valuation Accounts [Abstract]
Revenue Recognition and Valuation Accounts	REVENUE RECOGNITION AND VALUATION ACCOUNTS We establish the amount of our allowance for doubtful accounts based upon factors relating to the credit risk of specific customers, current market conditions, and other information. Our allowance for doubtful accounts was approximately $6.1 million and $6.0 million at September 30, 2017 , and December 31, 2016 , respectively. Revenues related to flights generated by our Air Medical segment are recorded net of contractual allowances under agreements with third party payors and estimated uncompensated care when the services are provided. The allowance for contractual discounts was $129.2 million and $111.9 million as of September 30, 2017 and December 31, 2016 , respectively. The allowance for uncompensated care was $47.7 million and $46.3 million as of September 30, 2017 and December 31, 2016 , respectively. Included in the allowance for uncompensated care listed above is the value of services to patients who are unable to pay when it is determined that they qualify for charity care. The value of these services was $1.3 million and $2.2 million for the quarters ended September 30, 2017 and 2016 , respectively. The value of these services was $5.7 million and $6.9 million for the nine months ended September 30, 2017 and 2016 , respectively. The estimated cost of providing charity services was $0.3 million for the quarter ended September 30, 2017 and $0.5 million for the quarter ended September 30, 2016 . The estimated cost of providing charity services was $1.3 million and $ 1.8 million for the nine months ended September 30, 2017 and 2016 , respectively. The estimated costs of providing charity services are based on a calculation that applies a ratio of costs to the charges for uncompensated charity care. The ratio of costs to charges is based on our Air Medical segment’s total expenses divided by gross patient service revenue. The allowance for contractual discounts and estimated uncompensated care (expressed as a percentage of gross segment accounts receivable) as of the dates listed below was as follows: September 30, 2017 December 31, 2016 Allowance for Contractual Discounts 58 % 56 % Allowance for Uncompensated Care 21 % 23 % Under a three-year contract that commenced on September 29, 2012, our Air Medical affiliate provided multiple services to a customer in the Middle East, including helicopter leasing, emergency medical helicopter flight services, aircraft maintenance, provision of spare parts, insurance coverage for the customer-owned aircraft, training services, and base construction. Each of the major services mentioned above qualified as separate units of accounting under the accounting guidance for such arrangements. The selling price for each specific service was determined based upon third-party evidence and estimates. As discussed in greater detail in our Form 10-K for the year ended December 31, 2016 and elsewhere herein, this contract, after being extended one year, lapsed on September 30, 2016 . We have also established valuation reserves related to obsolete and slow-moving spare parts inventory. The inventory valuation reserves were $18.4 million and $17.3 million at September 30, 2017 and December 31, 2016 , respectively.

Fair Value Measurements

Fair Value Measurements	9 Months Ended
	Sep. 30, 2017
Fair Value Disclosures [Abstract]
Fair Value Measurements	FAIR VALUE MEASUREMENTS Accounting standards require that assets and liabilities carried at fair value will be classified and disclosed in one of the following three categories: Level 1: Quoted market prices in active markets for identical assets or liabilities. Level 2: Observable market based inputs or unobservable inputs that are corroborated by market data. Level 3: Unobservable inputs that are not corroborated by market data. The following table summarizes the valuation of our investments and financial instruments by the above pricing levels as of the valuation dates listed: September 30, 2017 Total (Level 1) (Level 2) (Thousands of dollars) Investments: Money market mutual funds $ 5,278 $ 5,278 $ — Commercial paper 9,413 — 9,413 U.S. Government agencies 13,491 — 13,491 Corporate bonds and notes 188,235 — 188,235 216,417 5,278 211,139 Deferred compensation plan assets 2,630 2,630 — Total $ 219,047 $ 7,908 $ 211,139 December 31, 2016 Total (Level 1) (Level 2) (Thousands of dollars) Investments: Money market mutual funds $ 18,118 $ 18,118 $ — Commercial paper 27,867 — 27,867 U.S. government agencies 13,263 — 13,263 Corporate bonds and notes 243,582 — 243,582 302,830 18,118 284,712 Deferred compensation plan assets 2,394 2,394 — Total $ 305,224 $ 20,512 $ 284,712 We hold our short-term investments in an investment fund consisting of high quality money market instruments of governmental and private issuers, which is classified as a short-term investment. Level 1 inputs are quoted prices (unadjusted) for identical assets or liabilities in active markets. These items are traded with sufficient frequency and volume to provide pricing on an ongoing basis. The fair values of the investments in these funds are based on observable market prices, and therefore, have been categorized in Level 1 in the fair value hierarchy. Level 2 inputs reflect quoted prices for identical assets or liabilities that are not actively traded. These items may not be traded daily; examples include commercial paper, corporate bonds and U.S. government agencies debt. There have been no reclassifications of assets between Level 1 and Level 2 investments during the periods covered by the financial statements included in this report. We hold no Level 3 investments. Investments reflected on our balance sheets as Other Assets, which we hold to fund liabilities under our Officers’ Deferred Compensation Plan, consist mainly of multiple investment funds that are highly liquid and diversified. Cash, accounts receivable, accounts payable and accrued liabilities, and our revolving credit facility debt all had fair values approximating their carrying amounts at September 30, 2017 and December 31, 2016 . Our determination of the estimated fair value of our 5.25% Senior Notes due 2019 and our revolving credit facility debt is derived using Level 2 inputs, including quoted market indications of similar publicly-traded debt. The fair value of our 5.25% Senior Notes due 2019, based on quoted market prices, was $489.2 million and $474.4 million at September 30, 2017 and December 31, 2016 , respectively.

Long Term Debt

Long Term Debt	9 Months Ended
	Sep. 30, 2017
Debt Disclosure [Abstract]
Long Term Debt	LONG-TERM DEBT The components of long-term debt as of the dates indicated below were as follows: September 30, 2017 December 31, 2016 Principal Unamortized Principal Unamortized (Thousands of dollars) Senior Notes issued March 17, 2014, interest only payable semi-annually at 5.25%, maturing March 15, 2019 $ 500,000 $ 1,818 $ 500,000 $ 2,753 Revolving Credit Facility due October 1, 2018 with a group of commercial banks, interest payable at variable rates 100,000 — 134,000 — Total long-term debt $ 600,000 $ 1,818 $ 634,000 $ 2,753 Our 5.25% Senior Notes (the “2019 Notes”) will mature on March 15, 2019 , are unconditionally guaranteed on a senior basis by each of PHI, Inc.’s wholly-owned domestic subsidiaries, and are the general, unsecured obligations of PHI, Inc. and the guarantors. Interest is payable semi-annually on March 15 and September 15 of each year. PHI has the option to redeem some or all of the 2019 Notes at any time on or after March 15, 2016 at specified redemption prices. The indenture governing the 2019 Notes (the “2019 Indenture”) contains, among other things, certain restrictive covenants, including limitations on incurring indebtedness, creating liens, selling assets and entering into certain transactions with affiliates. The covenants also limit PHI’s ability to, among other things, pay cash dividends on common stock, repurchase or redeem common or preferred equity, prepay subordinated debt and make certain investments. Upon the occurrence of a “Change in Control Repurchase Event” (as defined in the 2019 Indenture), PHI will be required, unless it has previously elected to redeem the 2019 Notes as described above, to make an offer to purchase the 2019 Notes for a cash price equal to 101% of their principal amount. Revolving Credit Facility – We have an amended and restated revolving credit facility (our “credit facility”) that matures on October 1, 2018 . Under this facility, we can borrow up to $150.0 million at floating interest rates based on either the London Interbank Offered Rate plus 225 basis points or the prime rate (each as defined in our credit facility), at our option. Our credit facility includes usual and customary covenants and events of default for credit facilities of its type. Our ability to borrow under the credit facility is conditioned upon our continued compliance with such covenants, including, among others, (i) covenants that restrict our ability to engage in certain asset sales, mergers or other fundamental changes, to incur liens or to engage in certain other transactions or activities and (ii) financial covenants that stipulate that PHI will maintain a consolidated working capital ratio of at least 2 to 1, a net funded debt to consolidated net worth ratio not greater than 1.5 to 1, a fixed charge coverage ratio of at least 1.1 to 1 if our short term investments fall below $150.0 million , and consolidated net worth of at least $450.0 million (with all such terms or amounts as defined in or determined under our credit facility). As of September 30, 2017 , we believe we were in compliance with these covenants. Letter of Credit Facility - We maintain a separate letter of credit facility that had $12.3 million and $13.0 million in letters of credit outstanding at September 30, 2017 and December 31, 2016 respectively. We have letters of credit securing our workers compensation policies, a traditional provider contract, and a bond relating to foreign operations. We also have outstanding a letter of credit for $7.8 million issued under our $150.0 million credit facility that reduces the amount we can borrow under that facility. The letter of credit was issued to guaranty our performance under an international contract that was awarded in late 2016 . Other - Cash paid to fund interest expense under our outstanding indebtedness was $14.3 million for the quarter ended September 30, 2017 and $13.9 million for the quarter ended September 30, 2016 . Cash paid to fund interest expense under our outstanding indebtedness was $29.5 million for the nine months ended September 30, 2017 and $28.3 million for the nine months ended September 30, 2016 . PHI, Inc. has cash management arrangements with certain of its principal subsidiaries, in which substantial portions of the subsidiaries’ cash is regularly advanced to PHI, Inc. Although PHI, Inc. periodically repays these advances to fund the subsidiaries’ cash requirements throughout the year, at any given point in time PHI, Inc. may owe a substantial sum to its subsidiaries under these advances, which, in accordance with generally accepted accounting principles, are eliminated in consolidation and therefore not recognized on our consolidated balance sheets. For additional information, see Note 13.

Earnings Per Share

Earnings Per Share	9 Months Ended
	Sep. 30, 2017
Earnings Per Share [Abstract]
Earnings Per Share	EARNINGS PER SHARE The components of basic and diluted earnings per share for the quarter and nine months ended September 30, 2017 and 2016 are as follows: Quarter Ended Nine Months Ended 2017 2016 2017 2016 (Thousands of dollars) Weighted average outstanding shares of common stock, basic 15,799 15,683 15,750 15,655 Dilutive effect of unvested restricted stock units — — — — Weighted average outstanding shares of common stock, diluted (1) 15,799 15,683 15,750 15,655 (1) For the three months ended September 30, 2017 and 2016 , 0 and 52,126 unvested restricted stock units were excluded from the weighted average outstanding shares of common stock, diluted, respectively as they were anti-dilutive to earnings per share. For the nine months ended September 30, 2017 and 2016, 0 and 22,221 unvested restricted stock units were excluded from the weighted average outstanding shares of common stock, diluted, respectively as they were anti-dilutive to earnings per share.

Stock-Based Compensation

Stock-Based Compensation	9 Months Ended
	Sep. 30, 2017
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Stock-Based Compensation	STOCK-BASED COMPENSATION We recognize the cost of employee compensation received in the form of equity instruments based on the grant date fair value of those awards. The table below sets forth the total amount of stock-based compensation expense for the nine months and quarter ended September 30, 2017 and 2016 . Quarter Ended Nine Months Ended 2017 2016 2017 2016 (Thousands of dollars) Stock-based compensation expense: Time-based restricted stock units $ 582 $ 631 $ 1,678 $ 1,847 Performance-based restricted stock units 689 823 1,396 2,502 Total stock-based compensation expense $ 1,271 $ 1,454 $ 3,074 $ 4,349 During the quarter and nine months ended September 30, 2017 , 26,296 and 472,913 time-based restricted units, respectively, and 4,646 and 371,045 performance-based restricted units were awarded to managerial employees. During the quarter and nine months ended September 30, 2016 , 10,992 and 25,280 time-based restricted units, respectively, and 2,318 and 310,481 performance-based restricted units were awarded to managerial employees, respectively.

Asset Disposals

Asset Disposals	9 Months Ended
	Sep. 30, 2017
Property, Plant and Equipment [Abstract]
Asset Disposals	ASSET DISPOSALS During the third quarter of 2017 , we disposed of one medium aircraft and related parts inventory utilized in the Oil and Gas segment. This aircraft no longer met our strategic needs. During the first two quarters of 2017 , we disposed of five medium aircraft and related parts inventory in the Oil & Gas segment. These aircraft no longer met our strategic needs. During the third quarter of 2016 , we sold four light aircraft previously utilized in the Oil and Gas segment. Cash proceeds totaled $2.2 million , resulting in a $0.1 million loss on the sale of these assets. In the first two quarters of 2016 we sold five light and three medium aircraft and related parts inventory utilized in the Oil and Gas segment. Cash proceeds totaled $11.0 million , resulting in a gain on the sale of these assets of $3.9 million . These aircraft no longer met our strategic needs.

Commitments and Contingencies

Commitments and Contingencies	9 Months Ended
	Sep. 30, 2017
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies	COMMITMENTS AND CONTINGENCIES Commitments – We currently have no aircraft purchase commitments. Total aircraft deposits of $0.5 million were included in Other Assets as of September 30, 2017 . This amount represents a deposit on a future lease buyout option. In the event we do not exercise the buyout option, the deposit will be applied against lease payments. As of September 30, 2017 , we had options to purchase aircraft under leases, with such purchase options becoming exercisable in 2018 through 2020. The aggregate option purchase prices are $127.0 million in 2018 , $129.0 million in 2019 , and $22.7 million in 2020 . Under current conditions, we believe it is unlikely that we will exercise the 2018 purchase options, unless opportunistic conditions arise. Environmental Matters – PHI has recorded an estimated liability of $0.15 million as of September 30, 2017 for environmental response costs. Previously, PHI conducted environmental surveys of its former Lafayette Facility located at the Lafayette Regional Airport, which we vacated in 2001, PHI has determined that limited soil and groundwater contamination exist at two parcels of land at the former facility. An Assessment Report for both parcels was submitted in 2003 (and updated in 2006) to the Louisiana Department of Environmental Quality (LDEQ) and the Louisiana Department of Natural Resources (LDNR). Approvals for the Assessment Report were received from the LDEQ and LDNR in 2010 and 2011, respectively. Since that time, PHI has performed groundwater sampling of the required groundwater monitor well installations at both parcels and submitted these sampling reports to the LDEQ. Pursuant to an agreement with the LDEQ, PHI provided groundwater sample results semi-annually to the LDEQ for both parcels from 2005 to 2015. LDEQ approved a reduction in the sampling program from semi-annual to annual groundwater monitoring in 2015. Based on PHI’s working relationship and agreements with the LDEQ, and the results of ongoing former facility parcel monitoring, PHI believes that ultimate remediation costs for the subject parcels will not be material to PHI’s consolidated financial position, operations or cash flows. Legal Matters – On September 25, 2017, we brought a suit in the U.S. District Court for the Western District of Louisiana against Office & Professional Employees International Union and Office & Professional Employees International Union, Local 108 (Civil Action No. 6:17 cv 01216), which collectively represent our domestic pilot workforce. In this suit, we seek declaratory relief and other remedies under federal law to confirm that we can increase the wages of most of our unionized pilots and provide enhanced benefits of employment without negotiating these proposed changes with the defendants. We are in the early stages of this proceeding. From time to time, we are involved in various legal actions incidental to our business, including actions relating to employee claims, medical malpractice claims, tax issues, grievance hearings before labor regulatory agencies, and miscellaneous third party tort actions. The outcome of these proceedings is not predictable. However, based on current circumstances, we do not believe that the ultimate resolution of our presently pending proceedings, after considering available defenses and any insurance coverage or indemnification rights, will have a material adverse effect on our financial position, results of operations or cash flows. Operating Leases – We lease certain aircraft, facilities, and equipment used in our operations. The related lease agreements, which include both non-cancelable and month-to-month terms, generally provide for fixed monthly rentals, and certain real estate leases also include renewal options. We generally pay all insurance, taxes, and maintenance expenses associated with these leases. All aircraft leases contain purchase options exercisable by us at certain dates in the lease agreements. At September 30, 2017 , we had approximately $194.9 million in aggregate commitments under operating leases of which approximately $10.7 million is payable through the fourth quarter of 2017. The total lease commitments include $182.0 million for aircraft and $12.9 million for facility lease commitments.

Segment Information

Segment Information	9 Months Ended
	Sep. 30, 2017
Segment Reporting [Abstract]
Segment Information	SEGMENT INFORMATION PHI is primarily a provider of helicopter transport services, including helicopter maintenance and repair services. We report our financial results through the three reportable segments further described below. A segment’s operating profit or loss is its operating revenues less its direct expenses and selling, general and administrative expenses. A portion of our total selling, general and administrative expenses is charged directly to each segment, and a small portion is allocated to that segment. Direct charges represent the vast majority of segment selling, general and administrative expenses. Allocated selling, general and administrative expenses are based primarily on total segment costs as a percentage of total operating costs. Oil and Gas Segment - Our Oil and Gas segment, headquartered in Lafayette, Louisiana, provides helicopter services primarily for the major integrated and independent oil and gas production companies transporting personnel or equipment to offshore platforms in the Gulf of Mexico. Our customers include Shell Oil Company, BP America Production Company, ExxonMobil Production Company, and ConocoPhillips Company, with whom we have worked for 30 or more years, and ENI Petroleum, with whom we have worked for more than 15 years. At September 30, 2017 , we had available for use 126 aircraft in this segment. Operating revenue from our Oil and Gas segment is derived mainly from contracts that include a fixed monthly rate for a particular model of aircraft, plus a variable payments based on the amount of flight time. A small portion of our Oil and Gas segment revenue is derived from providing services on an "ad-hoc" basis. Operating costs for the Oil and Gas segment are primarily aircraft operation costs, including costs for pilots and maintenance personnel. Total fuel cost is included in direct expense and any reimbursement of a portion of these costs above a contracted amount is included in revenue. We typically operate under fixed-term contracts with our customers, a substantial portion of which are competitively bid. Our fixed-term contracts have terms of one to seven years (subject to provisions permitting early termination by the customers), with payment in U.S. dollars. For the quarters September 30, 2017 and 2016 , respectively, approximately 50% and 49% of our total operating revenues were generated by our Oil and Gas segment, with approximately 89% and 92% of these revenues from fixed-term customer contracts. For the nine months ended September 30, 2017 and 2016 , respectively, approximately 51% of our total operating revenues were generated by our Oil and Gas segment, with approximately 90% and 92% of these revenues from fixed-term customer contracts. The remaining 10% and 8% of these revenues were attributable to work in the spot market and ad hoc flights for contracted customers. Air Medical Segment - The operations of our Air Medical segment are headquartered in Phoenix, Arizona, where we maintain significant separate facilities and administrative staff dedicated to this segment. We provide Air Medical transportation services for hospitals and emergency service agencies throughout the U.S. As of September 30, 2017 , our Air Medical segment operated approximately 105 aircraft in 18 states at 72 separate locations. Our Air Medical segment operates primarily under the independent provider model and, to a lesser extent, under the traditional provider model. Under the independent provider model, we have no fixed revenue stream and compete for transport referrals on a daily basis with other independent operators in the area. Under the traditional provider model, we contract directly with the customer to provide their transportation services, with the contracts typically awarded or renewed through competitive bidding. For the quarter ended September 30, 2017 and 2016 , approximately 47% and 47% of our total operating revenues were generated by our Air Medical segment, respectively. For the nine months ended September 30, 2017 and 2016 , approximately 45% of our total operating revenues were generated by our Air Medical segment. As an independent provider, we bill for our services on the basis of a flat rate plus a variable charge per patient-loaded mile, regardless of aircraft model, and are typically compensated by private insurance, Medicaid or Medicare, or directly by transported patients who self-pay. As further described in Note 3, revenues are recorded net of contractual allowances under agreements with third party payors and estimated uncompensated care at the time the services are provided. Contractual allowances and uncompensated care are estimated based on historical collection experience by payor category (consisting mainly of insurance, Medicaid, Medicare, and self-pay). Estimates regarding the payor mix and changes in reimbursement rates are the factors most subject to sensitivity and variability in calculating our allowances. We compute a historical payment analysis of accounts fully closed, by category. Provisions for contractual discounts and estimated uncompensated care for our Air Medical segment (expressed as a percentage of gross segment billings) were as follows: Quarter Ended Nine Months Ended 2017 2016 2017 2016 Provision for contractual discounts 65 % 65 % 66 % 67 % Provision for uncompensated care 6 % 9 % 7 % 6 % These percentages are affected by various factors, including rate increases and changes in the number of transports by payor mix. Net reimbursement per transport from commercial payors generally increases when a rate increase is implemented. Net reimbursement from certain commercial payors, as well as Medicare and Medicaid, generally does not increase proportionately with rate increases. Net revenue attributable to Insurance, Medicare, Medicaid, and Self-Pay (expressed as a percentage of net Air Medical revenues) were as follows: Quarter Ended Nine Months Ended 2017 2016 2017 2016 Insurance 73 % 75 % 72 % 72 % Medicare 17 % 17 % 18 % 18 % Medicaid 9 % 8 % 9 % 9 % Self-Pay 1 % — % 1 % 1 % We also have a limited number of contracts with hospitals under which we receive a fixed fee component for aircraft availability and a variable fee component for flight time. Most of our contracts with hospitals contain provisions permitting early termination by the hospital, typically with 180 days’ notice for any reason and generally with penalty. Those contracts generated approximately 15% and 27% of the segment’s revenues for the quarters ended September 30, 2017 and 2016 , respectively. For the nine months ended September 30, 2017 and 2016 , these contracts generated approximately 17% and 29% of the segment's revenues, respectively. Technical Services Segment - Our Technical Services segment provides helicopter repair and overhaul services for flight operations customers that own their aircraft. Costs associated with these services are primarily labor, and customers are generally billed at a percentage above our service costs. We also periodically provide flight services to governmental customers under this segment, including our agreement to operate six aircraft for the National Science Foundation in Antarctica, typically in the first and fourth quarters each year. Also included in this segment are our proprietary Helipass operations, which provide software as a service to certain of our Oil and Gas customers for the purpose of passenger check-in and compliance verification. For the quarter ended September 30, 2017 and 2016 , approximately 3% and 4% , respectively, of our total operating revenues were generated by our Technical Services segment. For the nine months ended September 30, 2017 and 2016 , approximately 4% , respectively, of our total operating revenues were generated by our Technical Services segment. Summarized financial information concerning our reportable operating segments for the three and nine months ended September 30, 2017 and 2016 is as follows: Quarter Ended Nine Months Ended 2017 2016 2017 2016 (Thousands of dollars) Segment operating revenues, net Oil and Gas $ 75,700 $ 77,551 $ 222,098 $ 249,173 Air Medical 70,280 74,482 192,840 220,089 Technical Services 4,187 6,060 16,271 19,983 Total operating revenues, net 150,167 158,093 431,209 489,245 Segment direct expenses (1) Oil and Gas (2) 81,467 82,832 236,878 262,148 Air Medical 51,120 56,562 152,363 172,603 Technical Services 3,761 5,742 12,565 15,432 Total segment direct expenses 136,348 145,136 401,806 450,183 Segment selling, general and administrative expenses Oil and Gas 1,148 1,705 4,501 4,838 Air Medical 3,136 3,056 9,280 8,293 Technical Services 338 266 1,032 763 Total segment selling, general and administrative expenses 4,622 5,027 14,813 13,894 Total segment expenses 140,970 150,163 416,619 464,077 Net segment (loss) profit Oil and Gas (6,915 ) (6,986 ) (19,281 ) (17,813 ) Air Medical 16,024 14,864 31,197 39,193 Technical Services 88 52 2,674 3,788 Total net segment profit 9,197 7,930 14,590 25,168 Other, net (3) 710 377 2,471 5,425 Unallocated selling, general and administrative costs (1) (6,779 ) (8,354 ) (23,878 ) (22,938 ) Interest expense (8,027 ) (7,719 ) (24,305 ) (22,792 ) (Loss) earnings before income taxes $ (4,899 ) $ (7,766 ) $ (31,122 ) $ (15,137 ) (1) Included in direct expenses and unallocated selling, general, and administrative costs are the depreciation and amortization expense amounts below: Depreciation and Amortization Expense Quarter Ended Nine Months Ended 2017 2016 2017 2016 (Thousands of dollars) Segment Direct Expense: Oil and Gas $ 9,615 $ 10,616 $ 29,301 $ 30,558 Air Medical 4,885 5,267 15,581 14,654 Technical Services 146 141 440 426 Total $ 14,646 $ 16,024 $ 45,322 $ 45,638 Unallocated SG&A $ 1,936 $ 2,269 $ 5,271 $ 7,416 (2) Includes Equity in (earnings) of unconsolidated affiliates, net. (3) Consists of (gains) losses on disposition of property and equipment and other income.

Investment in Variable Interest

Investment in Variable Interest Entity and Other Investments and Affiliates	9 Months Ended
	Sep. 30, 2017
Investment in Variable Interest Entity and Other Investments and Affiliates [Abstract]
Investment in Variable Interest Entity and Other Investments and Affiliates	INVESTMENT IN VARIABLE INTEREST ENTITY AND OTHER INVESTMENTS AND AFFILIATES We account for our investment in certain international operations as variable interest entities, which is defined as an entity that either (a) has insufficient equity to permit the entity to finance its operations without additional subordinated financial support or (b) has equity investors who lack the characteristics of a controlling financial interest. PHI Century Limited - As of September 30, 2017 , we had a 49% investment in the common stock of PHI Century Limited (“PHIC”), a Ghanaian entity. We acquired our 49% interest on May 26, 2011 , PHIC’s date of incorporation. The purpose of PHIC is to provide oil and gas flight services in Ghana and the West African region. For the quarter ended September 30, 2017 , we recorded income in equity of this unconsolidated affiliate of $0.1 million compared to a loss of $0.2 million for the quarter ended September 30, 2016 relative to our 49% equity ownership. For the nine months ended September 30, 2017 and 2016 , we recorded a loss in equity of this unconsolidated affiliate of $1.0 million and $0.3 million relative to our 49% equity ownership, respectively. We had $3.6 million and $2.0 million of trade receivables as of September 30, 2017 and December 31, 2016 , respectively, from PHIC. Our investment in the common stock of PHIC is included in Other Assets on our Condensed Consolidated Balance Sheets and was $0.4 million and $0.2 million at September 30, 2017 and December 31, 2016 , respectively. PHI-HNZ Australia Ltd - In the fourth quarter of 2016, the Company and HNZ Group, Inc. ("HNZ") jointly formed PHI-HNZ Australia Pty Ltd. ("PHI-HNZ"), a legal entity held 50% by PHI, Inc. and 50% by HNZ, to provide helicopter transportation services in support of a gas development project offshore of western Australia. PHI-HNZ began operations in April, 2017. For the quarter ended September 30, 2017 , we recorded $0.5 million of income in equity of this unconsolidated affiliate. For the nine months ended September 30, 2017 , we recorded a loss in equity of unconsolidated affiliate of $0.5 million , primarily related to startup costs associated with the contract. We had $5.9 million of trade receivables as of September 30, 2017 from PHI-HNZ. Our investment in common stock of PHI-HNZ is included in other long-term liabilities on our Consolidated Balance Sheets and was $(0.5) million at September 30, 2017 .

Other Comprehensive Income

Other Comprehensive Income	9 Months Ended
	Sep. 30, 2017
Equity [Abstract]
Other Comprehensive Income	OTHER COMPREHENSIVE INCOME Amounts reclassified from Accumulated other comprehensive income are not material and, therefore, not presented separately in the Condensed Consolidated Statements of Comprehensive Income.

Condensed Consolidating Financi

Condensed Consolidating Financial Information	9 Months Ended
	Sep. 30, 2017
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Condensed Consolidating Financial Information	CONDENSED CONSOLIDATING FINANCIAL INFORMATION As discussed further in Note 5, on March 17, 2014, PHI, Inc. issued $500.0 million aggregate principal amount of 5.25% Senior Notes due 2019 that are fully and unconditionally guaranteed on a joint and several, senior basis by all of PHI, Inc.’s domestic subsidiaries. PHI, Inc. directly or indirectly owns 100% of all of its domestic subsidiaries. The supplemental condensed financial information on the following pages sets forth, on a consolidated basis, the balance sheet, statement of operations, statement of comprehensive income, and statement of cash flows information for PHI, Inc. (“Parent Company”) the guarantor subsidiaries and the non-guarantor subsidiaries, each under separate headings (except for periods ending on or before December 31, 2016 , in which case such information for the guarantor and non-guarantor subsidiaries is presented together). The eliminating entries eliminate investments in subsidiaries, intercompany balances, and intercompany revenues and expenses. The condensed consolidating financial statements have been prepared on the same basis as the consolidated financial statements of PHI, Inc. The equity method is followed by the Parent Company within the financial information presented below. The transactions reflected in “Due to/from affiliates, net” in the following condensed consolidated statements of cash flows primarily consist of centralized cash management activities between PHI, Inc. and its subsidiaries, pursuant to which cash earned by the guarantor subsidiaries is regularly transferred to PHI, Inc. to be centrally managed. Because these balances are treated as short-term borrowings of the Parent Company, serve as a financing and cash management tool to meet our short-term operating needs, turn over quickly and are payable to the guarantor subsidiaries on demand, we present borrowings and repayments with our affiliates on a net basis within the condensed consolidating statement of cash flows. Net receivables from our affiliates are considered advances and net payables to our affiliates are considered borrowings, and both changes are presented as financing activities in the following condensed consolidating statements of cash flows. Due to the growth of our international affiliates in Trinidad and Australia which no longer qualify as minor subsidiaries under regulation S-X 210.3-10(h)6, we began reporting all of our non-guarantors subs in a separate column beginning with the quarter ended June 30, 2017. PHI, INC. AND SUBSIDIARIES CONDENSED CONSOLIDATING BALANCE SHEETS (Thousands of dollars) (Unaudited) September 30, 2017 Parent Guarantor Non-Guarantor Subsidiaries Eliminations Consolidated ASSETS Current Assets: Cash $ 50 $ 1,071 $ 1,870 $ — $ 2,991 Short-term investments 204,036 — — — 204,036 Accounts receivable – net 77,061 71,727 14,721 (10,772 ) 152,737 Intercompany receivable — 120,376 — (120,376 ) — Inventories of spare parts – net 70,617 8,628 — — 79,245 Prepaid expenses 9,916 1,948 142 — 12,006 Deferred income taxes 10,798 — — — 10,798 Income taxes receivable 500 9 — — 509 Total current assets 372,978 203,759 16,733 (131,148 ) 462,322 Investment in subsidiaries 390,840 — — (390,840 ) — Property and equipment – net 621,885 287,841 601 — 910,327 Restricted cash and investments 12,381 — 15 — 12,396 Other assets 8,076 956 — — 9,032 Total assets $ 1,406,160 $ 492,556 $ 17,349 $ (521,988 ) $ 1,394,077 LIABILITIES AND SHAREHOLDERS’ EQUITY Current Liabilities: Accounts payable $ 26,587 $ 3,557 $ 11,235 $ (10,772 ) $ 30,607 Accrued and other current liabilities 22,198 9,961 1,544 — 33,703 Intercompany payable 112,015 — 8,361 (120,376 ) — Total current liabilities 160,800 13,518 21,140 (131,148 ) 64,310 Long-term debt 598,182 — — — 598,182 Deferred income taxes and other long-term liabilities 65,117 83,891 516 — 149,524 Shareholders’ Equity: Common stock and paid-in capital 308,634 77,951 1,375 (79,326 ) 308,634 Accumulated other comprehensive loss (244 ) — — — (244 ) Retained earnings 273,671 317,196 (5,682 ) (311,514 ) 273,671 Total shareholders’ equity 582,061 395,147 (4,307 ) (390,840 ) 582,061 Total liabilities and shareholders’ equity $ 1,406,160 $ 492,556 $ 17,349 $ (521,988 ) $ 1,394,077 PHI, INC. AND SUBSIDIARIES CONDENSED CONSOLIDATING BALANCE SHEETS (Thousands of dollars) December 31, 2016 Parent Guarantor (1) Eliminations Consolidated ASSETS Current Assets: Cash $ 36 $ 2,560 $ — $ 2,596 Short-term investments 289,806 — — 289,806 Accounts receivable – net 71,458 66,807 — 138,265 Intercompany receivable — 57,904 (57,904 ) — Inventories of spare parts – net 61,834 8,568 — 70,402 Prepaid expenses 6,990 2,269 — 9,259 Deferred income taxes 10,798 — — 10,798 Income taxes receivable 558 (18 ) — 540 Total current assets 441,480 138,090 (57,904 ) 521,666 Investment in subsidiaries and others 353,160 — (353,160 ) — Property and equipment – net 589,104 314,873 — 903,977 Restricted investments 13,023 15 — 13,038 Other assets 8,660 1,099 — 9,759 Total assets $ 1,405,427 $ 454,077 $ (411,064 ) $ 1,448,440 LIABILITIES AND SHAREHOLDERS’ EQUITY Current Liabilities: Accounts payable $ 22,744 $ 5,960 $ — $ 28,704 Accrued and other current liabilities 18,725 9,621 — 28,346 Intercompany payable 57,904 — (57,904 ) — Total current liabilities 99,373 15,581 (57,904 ) 57,050 Long-term debt 631,247 — — 631,247 Deferred income taxes and other long-term liabilities 75,029 85,336 — 160,365 Shareholders’ Equity: Common stock and paid-in capital 305,815 79,191 (79,191 ) 305,815 Accumulated other comprehensive loss (478 ) — — (478 ) Retained earnings 294,441 273,969 (273,969 ) 294,441 Total shareholders’ equity 599,778 353,160 (353,160 ) 599,778 Total liabilities and shareholders’ equity $ 1,405,427 $ 454,077 $ (411,064 ) $ 1,448,440 (1) Foreign subsidiaries represent minor subsidiaries and are included in the guarantors’ subsidiaries amounts. PHI, INC. AND SUBSIDIARIES CONDENSED CONSOLIDATING STATEMENTS OF OPERATIONS (Thousands of dollars) (Unaudited) For the Quarter Ended September 30, 2017 Parent Guarantor Non-Guarantor Subsidiaries Eliminations Consolidated Operating revenues, net $ 79,644 $ 70,692 $ 7,784 $ (7,953 ) $ 150,167 Expenses: Direct expenses 83,727 51,247 9,765 (7,953 ) 136,786 Selling, general and administrative expenses 8,240 3,141 24 (4 ) 11,401 Total operating expenses 91,967 54,388 9,789 (7,957 ) 148,187 (Gain) Loss on disposal of assets, net (4 ) — — — (4 ) Equity in (income) loss of unconsolidated affiliates, net 112 — (550 ) — (438 ) Operating (loss) income (12,431 ) 16,304 (1,455 ) 4 2,422 Equity in net income of consolidated subsidiaries (14,850 ) — — 14,850 — Interest expense 8,027 — — — 8,027 Other income, net (709 ) (1 ) — 4 (706 ) (7,532 ) (1 ) — 14,854 7,321 (Loss) earnings before income taxes (4,899 ) 16,305 (1,455 ) (14,850 ) (4,899 ) Income tax (benefit) expense (1,622 ) — — — (1,622 ) Net (loss) earnings $ (3,277 ) $ 16,305 $ (1,455 ) $ (14,850 ) $ (3,277 ) PHI, INC. AND SUBSIDIARIES CONDENSED CONSOLIDATING STATEMENTS OF OPERATIONS (Thousands of dollars) For the Quarter Ended September 30, 2016 Parent Guarantor (1) Eliminations Consolidated Operating revenues, net $ 79,532 $ 78,561 $ — $ 158,093 Expenses: Direct expenses 83,188 61,750 — 144,938 Selling, general and administrative expenses 10,639 3,092 (350 ) 13,381 Total operating expenses 93,827 64,842 (350 ) 158,319 Loss on disposal of assets, net 85 — — 85 Equity in loss of consolidated affiliate 198 — — 198 Operating (loss) income (14,578 ) 13,719 350 (509 ) Equity in net income of consolidated subsidiaries (8,372 ) — 8,372 — Interest expense 7,716 3 — 7,719 Other income, net (812 ) — 350 (462 ) (1,468 ) 3 8,722 7,257 (Loss) earnings before income taxes (13,110 ) 13,716 (8,372 ) (7,766 ) Income tax (benefit) expense (8,143 ) 5,344 — (2,799 ) Net (loss) earnings $ (4,967 ) $ 8,372 $ (8,372 ) $ (4,967 ) (1) Foreign subsidiaries represent minor subsidiaries and are included in the guarantors’ subsidiaries amounts. CONDENSED CONSOLIDATING STATEMENTS OF OPERATIONS (Thousands of dollars) (Unaudited) For the Nine Months Ended September 30, 2017 Parent Guarantor Non-Guarantor Subsidiaries Eliminations Consolidated Operating revenues, net $ 228,973 $ 197,022 $ 15,987 $ (10,773 ) $ 431,209 Expenses: Direct expenses 238,669 155,434 16,920 (10,773 ) 400,250 Selling, general and administrative expenses 29,265 9,296 144 (14 ) 38,691 Total operating expenses 267,934 164,730 17,064 (10,787 ) 438,941 Loss (gain) on disposal of assets, net 4 (1 ) — — 3 Equity in loss (income) of unconsolidated affiliates, net 1,040 — 516 — 1,556 Operating (loss) income (40,005 ) 32,293 (1,593 ) 14 (9,291 ) Equity in net income of consolidated subsidiaries (32,093 ) — — 32,093 — Interest expense 24,283 22 — — 24,305 Other income, net (2,486 ) (2 ) — 14 (2,474 ) (10,296 ) 20 — 32,107 21,831 (Loss) earnings before income taxes (29,709 ) 32,273 (1,593 ) (32,093 ) (31,122 ) Income tax (benefit) expense (7,911 ) (1,413 ) — — (9,324 ) Net (loss) earnings $ (21,798 ) $ 33,686 $ (1,593 ) $ (32,093 ) $ (21,798 ) PHI, INC. AND SUBSIDIARIES CONDENSED CONSOLIDATING STATEMENTS OF OPERATIONS (Thousands of dollars) For the Nine Months Ended September 30, 2016 Parent Guarantor (1) Eliminations Consolidated Operating revenues, net $ 260,766 $ 228,479 $ — $ 489,245 Expenses: Direct expenses 264,761 185,148 — 449,909 Selling, general and administrative expenses 28,914 8,766 (848 ) 36,832 Total operating expenses 293,675 193,914 (848 ) 486,741 Gain on disposal of assets, net (3,854 ) — — (3,854 ) Equity in loss of unconsolidated affiliate 274 — — 274 Operating (loss) income (29,329 ) 34,565 848 6,084 Equity in net income of consolidated subsidiaries (20,462 ) — 20,462 — Interest expense 22,762 30 — 22,792 Other income, net (2,415 ) (4 ) 848 (1,571 ) (115 ) 26 21,310 21,221 (Loss) earnings before income taxes (29,214 ) 34,539 (20,462 ) (15,137 ) Income tax (benefit) expense (19,592 ) 14,077 — (5,515 ) Net (loss) earnings $ (9,622 ) $ 20,462 $ (20,462 ) $ (9,622 ) (1) Foreign subsidiaries represent minor subsidiaries and are included in the guarantors’ subsidiaries amounts. PHI, INC. AND SUBSIDIARIES CONDENSED CONSOLIDATING STATEMENTS OF COMPREHENSIVE INCOME (LOSS) (Thousands of dollars) (Unaudited) For the Quarter Ended September 30, 2017 Parent Guarantor Non-Guarantor Subsidiaries Eliminations Consolidated Net (loss) earnings $ (3,277 ) $ 16,305 $ (1,455 ) $ (14,850 ) $ (3,277 ) Unrealized gain on short-term investments 41 — — — 41 Changes in pension plan asset and benefit obligation (24 ) — — — (24 ) Tax effect of the above-listed adjustments (8 ) — — — (8 ) Total comprehensive (loss) income $ (3,268 ) $ 16,305 $ (1,455 ) $ (14,850 ) $ (3,268 ) PHI, INC. AND SUBSIDIARIES CONDENSED CONSOLIDATING STATEMENTS OF COMPREHENSIVE INCOME (LOSS) (Thousands of dollars) For the Quarter Ended September 30, 2016 Parent Guarantor (1) Eliminations Consolidated Net (loss) earnings $ (4,967 ) $ 8,372 $ (8,372 ) $ (4,967 ) Unrealized gain on short-term investments (494 ) — — (494 ) Changes in pension plan asset and benefit obligations 1 — — 1 Tax effect of the above-listed adjustments 178 — — 178 Total comprehensive (loss) income $ (5,282 ) $ 8,372 $ (8,372 ) $ (5,282 ) (1) Foreign subsidiaries represent minor subsidiaries and are included in the guarantors’ subsidiaries amounts. PHI, INC. AND SUBSIDIARIES CONDENSED CONSOLIDATING STATEMENTS OF COMPREHENSIVE INCOME (LOSS) (Thousands of dollars) (Unaudited) For the Nine Months Ended September 30, 2017 Parent Guarantor Non-Guarantor Subsidiaries Eliminations Consolidated Net (loss) earnings $ (21,798 ) $ 33,686 $ (1,593 ) $ (32,093 ) $ (21,798 ) Unrealized gain on short-term investments 370 — — — 370 Changes in pension plan asset and benefit obligation (2 ) — — — (2 ) Tax effect of the above-listed adjustments (134 ) — — — (134 ) Total comprehensive (loss) income $ (21,564 ) $ 33,686 $ (1,593 ) $ (32,093 ) $ (21,564 ) PHI, INC. AND SUBSIDIARIES CONDENSED CONSOLIDATING STATEMENTS OF COMPREHENSIVE INCOME (LOSS) (Thousands of dollars) For the Quarter Ended September 30, 2016 Parent Guarantor (1) Eliminations Consolidated Net (loss) earnings $ (9,622 ) $ 20,462 $ (20,462 ) $ (9,622 ) Unrealized gain on short-term investments 523 — — 523 Changes in pension plan asset and benefit obligations 3 — — 3 Tax effect of the above-listed adjustments (229 ) — — (229 ) Total comprehensive (loss) income $ (9,325 ) $ 20,462 $ (20,462 ) $ (9,325 ) (1) Foreign subsidiaries represent minor subsidiaries and are included in the guarantors’ subsidiaries amounts. PHI, INC. AND SUBSIDIARIES CONDENSED CONSOLIDATING STATEMENTS OF CASH FLOWS (Thousands of dollars) (Unaudited) For the Nine Months Ended September 30, 2017 Parent Guarantor Non-Guarantor Subsidiaries Eliminations Consolidated Net cash (used in) provided by operating activities $ (43,328 ) $ 33,670 $ 7,790 $ — $ (1,868 ) Investing activities: Purchase of property and equipment (49,227 ) — — — (49,227 ) Proceeds from asset dispositions 21 — — — 21 Purchase of short-term investments (268,525 ) — — — (268,525 ) Proceeds from sale of short-term investments 354,250 — — — 354,250 Net cash provided by (used in) investing activities 36,519 — — — 36,519 Financing activities: Proceeds from line of credit 99,150 — — — 99,150 Payments on line of credit (133,150 ) — — — (133,150 ) Repurchase of common stock (256 ) — — — (256 ) Due to/from affiliate, net 41,079 (34,699 ) (6,380 ) — — Net cash provided by (used in) financing activities 6,823 (34,699 ) (6,380 ) — (34,256 ) Increase (decrease) in cash 14 (1,029 ) 1,410 — 395 Cash, beginning of period 36 2,100 460 — 2,596 Cash, end of period $ 50 $ 1,071 $ 1,870 $ — $ 2,991 PHI, INC. AND SUBSIDIARIES CONDENSED CONSOLIDATING STATEMENTS OF CASH FLOWS (Thousands of dollars) For the Nine Months Ended September 30, 2016 Parent Guarantor (1) Eliminations Consolidated Net cash (used in) provided by operating activities $ (32,467 ) $ 25,319 $ — $ (7,148 ) Investing activities: Purchase of property and equipment (74,647 ) (303 ) — (74,950 ) Proceeds from asset dispositions 13,233 — — 13,233 Purchase of short-term investments (263,204 ) — — (263,204 ) Proceeds from sale of short-term investments 259,322 — — 259,322 Payments of deposits on aircraft (197 ) — — (197 ) Loan to unconsolidated affiliate (1,200 ) — — (1,200 ) Net cash used in investing activities (66,693 ) (303 ) — (66,996 ) Financing activities: Proceeds from line of credit 213,900 — — 213,900 Payments on line of credit (139,000 ) — — (139,000 ) Repurchase of common stock (524 ) — — (524 ) Due to/from affiliate, net 24,774 (24,774 ) — — Net cash provided by (used in) financing activities 99,150 (24,774 ) — 74,376 (Decrease) increase in cash (10 ) 242 — 232 Cash, beginning of period 46 2,361 — 2,407 Cash, end of period $ 36 $ 2,603 $ — $ 2,639 (1) Foreign subsidiaries represent minor subsidiaries and are included in the guarantors’ subsidiaries amounts.

Subsequent Event

Subsequent Event	9 Months Ended
	Sep. 30, 2017
Subsequent Events [Abstract]
Subsequent Event	SUBSEQUENT EVENT On October 30, 2017, we entered into an arrangement agreement with HNZ Group Inc. (“HNZ”), 2075568 Alberta ULC (the "Canadian Purchaser”), and Don E. Wall. Under this agreement, the Canadian Purchaser had agreed to (i) acquire 100% of the capital stock of HNZ, with a portion of the purchase price funded with the proceeds of CAN $167.5 million of term loans from us (collectively, the “PHI Loan”), and (ii) sell to us HNZ’s offshore aviation services business in New Zealand, Australia, the Philippines and Papua New Guinea (the “Offshore Business”) as payment of most of the amount owed under the PHI Loan. The balance of the PHI Loan is expected to be repaid on or prior to December 31, 2019 or at such other time as mutually agreed between us and the Canadian Purchaser. Completion of the transactions contemplated under the arrangement agreement is subject to various closing conditions, including receipt of HNZ shareholder approval and certain court approvals. Subject to these conditions, we currently anticipate acquiring the Offshore Business by the end of January 2018. If the arrangement agreement is terminated under certain circumstances, HNZ may be obligated to make certain termination payments, including a termination fee of CAN $6.5 million payable to us.

Basis of Presentation (Policies

Basis of Presentation (Policies)	9 Months Ended
	Sep. 30, 2017
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Recently Adopted Accounting Pronouncements	Recently Adopted Accounting Pronouncements - Effective January 1, 2017, we adopted Accounting Standards Update (“ASU”) 2016-09, Compensation - Stock Compensation (Topic 718): Improvements to Employee Share-Based Payment Accounting, which was issued by the Financial Accounting Standards Board (“FASB”) in March 2016 . This new standard requires that excess tax benefits and deficiencies resulting from stock-based compensation awards vesting and exercises be recognized in the income statement. Previously, these amounts were recognized in additional paid-in capital. As a result, during the first quarter of 2017 we recorded a cumulative-effect adjustment of $1.0 million increasing retained earnings and decreasing deferred tax liability on our balance sheet dated September 30, 2017 . Accordingly, we recorded income tax expense of $1.6 million in our consolidated statement of income for the nine months ended September 30, 2017 , in recognition of excess tax deficiencies related to equity compensation. Under this new standard, the corresponding cash flows are now reflected in cash provided by operating activities instead of financing activities, as was previously required. ASU 2016-09 also allows an employer with a statutory income tax withholding obligation to withhold shares with a fair value up to the amount of tax owed using the maximum statutory tax rate in the employee’s applicable jurisdiction. We have elected to continue to withhold the minimum statutory withholding obligation for outstanding awards. We have also elected to continue to estimate equity award forfeitures expected to occur to determine the amount of compensation cost to be recognized in each period. New Accounting Pronouncements - In May 2014, the FASB issued Accounting Standards Update ASU 2014-09, Revenue from Contracts with Customers , which provides a single comprehensive model for entities to use in accounting for revenue arising from contracts with customers. Entities can transition to the standard either retrospectively or as a cumulative effect adjustment as of the date of adoption. The new standard will be effective for the Company beginning on January 1, 2018. Revenues from our Oil and Gas segment and Air Medical segment hospital contracts are primarily comprised of a fixed monthly fee for a particular model of aircraft, plus a variable component based on flight time. Under the independent provider programs of our Air Medical segment, our revenues are based on a flat rate plus a variable charge per patient-loaded mile, and are recorded net of contractual allowances. We also generate revenue on a cost-plus basis in our Technical Services segment. Based on our initial assessment, we do not expect the adoption of this ASU to have a material impact on our condensed consolidated financial statements. Remaining implementation matters include establishing new policies, procedures, and controls and quantifying any adoption date adjustments. We plan to adopt this standard on January 1, 2018 utilizing the modified retrospective method. In February 2016, the FASB issued ASU 2016-02, Leases , which replaces the existing guidance on leasing transactions in ASC 840 to require recognition of the assets and liabilities for the rights and obligations created by those leases on the balance sheet. We are currently evaluating the effects of this standard, and expect the adoption of this standard will result in a material change to our consolidated assets and liabilities based on our lease portfolio as of September 30, 2017 . We plan to adopt this standard beginning January 1, 2019. In October 2016, the FASB issued ASU 2016-16, Income Taxes (Topic 740): Intra-Entity Transfers of Assets Other than Inventory , which will require an entity to recognize the income tax consequences of an intra-entity transfer of an asset, other than inventory, when the transfer occurs. ASU 2016-16 is effective for annual periods beginning after December 15, 2017, including interim periods within those annual periods. The effects of this standard on our financial position, results of operations, and cash flows are not yet known. We plan to adopt this standard beginning January 1, 2018. In January 2017, the FASB issued ASU 2017-01, Business Combinations (Topic 805): Clarifying the Definition of a Business . ASU 2017-01 clarifies the definition of a business and requires that an entity apply certain criteria in order to determine when a set of assets and activities qualifies as a business. The adoption of this standard is expected to result in fewer acquisitions of properties qualifying as acquisitions of businesses and, accordingly, acquisition costs for those acquisitions that do not qualify as businesses will be capitalized rather than expensed. This standard is effective for fiscal years beginning after December 15, 2017, and interim periods within those fiscal years, and should be applied on a prospective basis. Early adoption is permitted. The effects of this standard on our financial position, results of operations, and cash flows are not yet known. We plan to adopt this standard beginning January 1, 2018. In January 2017, the FASB issued ASU 2017-04, Intangibles-Goodwill and Other (Topic 350): Simplifying the Test for Goodwill Impairment . ASU 2017-04 simplifies the current two-step goodwill impairment test by eliminating the second step of the test. The new standard requires a one-step impairment test in which an entity compares the fair value of a reporting unit with its carrying amount and recognizes an impairment charge for the amount by which the carrying amount exceeds the reporting unit’s fair value, if any. This standard is effective for fiscal years beginning after December 15, 2019, and interim periods within those fiscal years, and should be applied on a prospective basis. Early adoption is permitted for interim or annual goodwill impairment tests performed on testing dates after January 1, 2017. We do not expect this ASU to have a material impact on our consolidated financial statements.

Investments (Tables)

Investments (Tables)	9 Months Ended
	Sep. 30, 2017
Investments, Debt and Equity Securities [Abstract]
Components of Investments	Investments consisted of the following as of September 30, 2017 : Cost Basis Unrealized Unrealized Fair (Thousands of dollars) Investments: Money market mutual funds $ 5,278 $ — $ — $ 5,278 Commercial paper 9,423 — (10 ) 9,413 U.S. Government agencies 13,505 — (14 ) 13,491 Corporate bonds and notes 188,515 3 (283 ) 188,235 Subtotal 216,721 3 (307 ) 216,417 Deferred compensation plan assets included in other assets 2,630 — — 2,630 Total $ 219,351 $ 3 $ (307 ) $ 219,047 Investments consisted of the following as of December 31, 2016 : Cost Basis Unrealized Gains Unrealized Losses Fair Value (Thousands of dollars) Investments: Money market mutual funds $ 18,118 $ — $ — $ 18,118 Commercial paper 27,906 — (39 ) 27,867 U.S. government agencies 13,295 — (32 ) 13,263 Corporate bonds and notes 244,202 2 (622 ) 243,582 Subtotal 303,521 2 (693 ) 302,830 Deferred compensation plan assets included in other assets 2,394 — — 2,394 Total $ 305,915 $ 2 $ (693 ) $ 305,224
Cost and Fair Value of Debt Investments Based on Maturities	The following table presents the cost and fair value of our debt investments based on maturities as of: September 30, 2017 December 31, 2016 Amortized Fair Amortized Fair (Thousands of dollars) Due in one year or less $ 133,633 $ 133,481 $ 184,587 $ 184,334 Due within two years 77,810 77,658 100,816 100,378 Total $ 211,443 $ 211,139 $ 285,403 $ 284,712
Average Coupon Rate Percentage and Average Days to Maturity of Debt	The following table presents the average coupon rate percentage and the average days to maturity of our debt investments as of: September 30, 2017 December 31, 2016 Average Average Average Average Commercial paper 1.236 228 1.001 184 U.S. Government agencies 1.213 325 0.970 400 Corporate bonds and notes 1.715 295 1.745 318
Investments in Continuous Unrealized Loss Position for Less Than Twelve Months	The following table presents the fair value and unrealized losses related to our investments that have been in a continuous unrealized loss position for less than twelve months as of: September 30, 2017 December 31, 2016 Fair Value Unrealized Fair Value Unrealized (Thousands of dollars) Commercial paper $ 9,413 $ (10 ) $ 27,867 $ (39 ) U.S. Government agencies 9,495 (10 ) 13,263 (32 ) Corporate bonds and notes 102,767 (173 ) 210,836 (602 ) Total $ 121,675 $ (193 ) $ 251,966 $ (673 )
Investments in Continuous Unrealized Loss Position for More Than Twelve Months	The following table presents the fair value and unrealized losses related to our investments that have been in a continuous unrealized loss position for more than twelve months as of: September 30, 2017 December 31, 2016 Fair Value Unrealized Fair Value Unrealized (Thousands of dollars) U.S. Government agencies $ 3,996 $ (4 ) $ — $ — Corporate bonds and notes 77,187 (110 ) 24,196 (20 ) Total $ 81,183 $ (114 ) $ 24,196 $ (20 )

Revenue Recognition and Valua24

Revenue Recognition and Valuation Accounts (Tables)	9 Months Ended
	Sep. 30, 2017
Revenue Recognition And Valuation Accounts [Abstract]
Schedule of Allowance for Contractual Discounts and Estimated Uncompensated Care as a Percentage of Gross Segment Accounts Receivable	The allowance for contractual discounts and estimated uncompensated care (expressed as a percentage of gross segment accounts receivable) as of the dates listed below was as follows: September 30, 2017 December 31, 2016 Allowance for Contractual Discounts 58 % 56 % Allowance for Uncompensated Care 21 % 23 %

Fair Value Measurements (Tables

Fair Value Measurements (Tables)	9 Months Ended
	Sep. 30, 2017
Fair Value Disclosures [Abstract]
Summary of Valuation of Investments and Financial Instruments Pricing Levels	The following table summarizes the valuation of our investments and financial instruments by the above pricing levels as of the valuation dates listed: September 30, 2017 Total (Level 1) (Level 2) (Thousands of dollars) Investments: Money market mutual funds $ 5,278 $ 5,278 $ — Commercial paper 9,413 — 9,413 U.S. Government agencies 13,491 — 13,491 Corporate bonds and notes 188,235 — 188,235 216,417 5,278 211,139 Deferred compensation plan assets 2,630 2,630 — Total $ 219,047 $ 7,908 $ 211,139 December 31, 2016 Total (Level 1) (Level 2) (Thousands of dollars) Investments: Money market mutual funds $ 18,118 $ 18,118 $ — Commercial paper 27,867 — 27,867 U.S. government agencies 13,263 — 13,263 Corporate bonds and notes 243,582 — 243,582 302,830 18,118 284,712 Deferred compensation plan assets 2,394 2,394 — Total $ 305,224 $ 20,512 $ 284,712

Long Term Debt (Tables)

Long Term Debt (Tables)	9 Months Ended
	Sep. 30, 2017
Debt Disclosure [Abstract]
Components of Long-term Debt	The components of long-term debt as of the dates indicated below were as follows: September 30, 2017 December 31, 2016 Principal Unamortized Principal Unamortized (Thousands of dollars) Senior Notes issued March 17, 2014, interest only payable semi-annually at 5.25%, maturing March 15, 2019 $ 500,000 $ 1,818 $ 500,000 $ 2,753 Revolving Credit Facility due October 1, 2018 with a group of commercial banks, interest payable at variable rates 100,000 — 134,000 — Total long-term debt $ 600,000 $ 1,818 $ 634,000 $ 2,753

Earnings Per Share (Tables)

Earnings Per Share (Tables)	9 Months Ended
	Sep. 30, 2017
Earnings Per Share [Abstract]
Components of Basic and Diluted Earnings Per Share	The components of basic and diluted earnings per share for the quarter and nine months ended September 30, 2017 and 2016 are as follows: Quarter Ended Nine Months Ended 2017 2016 2017 2016 (Thousands of dollars) Weighted average outstanding shares of common stock, basic 15,799 15,683 15,750 15,655 Dilutive effect of unvested restricted stock units — — — — Weighted average outstanding shares of common stock, diluted (1) 15,799 15,683 15,750 15,655 (1) For the three months ended September 30, 2017 and 2016 , 0 and 52,126 unvested restricted stock units were excluded from the weighted average outstanding shares of common stock, diluted, respectively as they were anti-dilutive to earnings per share. For the nine months ended September 30, 2017 and 2016, 0 and 22,221 unvested restricted stock units were excluded from the weighted average outstanding shares of common stock, diluted, respectively as they were anti-dilutive to earnings per share.

Stock-Based Compensation (Table

Stock-Based Compensation (Tables)	9 Months Ended
	Sep. 30, 2017
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Summary of Share Based Compensation Expense	The table below sets forth the total amount of stock-based compensation expense for the nine months and quarter ended September 30, 2017 and 2016 . Quarter Ended Nine Months Ended 2017 2016 2017 2016 (Thousands of dollars) Stock-based compensation expense: Time-based restricted stock units $ 582 $ 631 $ 1,678 $ 1,847 Performance-based restricted stock units 689 823 1,396 2,502 Total stock-based compensation expense $ 1,271 $ 1,454 $ 3,074 $ 4,349

Segment Information (Tables)

Segment Information (Tables)	9 Months Ended
	Sep. 30, 2017
Segment Reporting [Abstract]
Schedule of Provisions for Contractual Discounts and Estimated Uncompensated Care as a Percentage of Gross Segment Billings	Provisions for contractual discounts and estimated uncompensated care for our Air Medical segment (expressed as a percentage of gross segment billings) were as follows: Quarter Ended Nine Months Ended 2017 2016 2017 2016 Provision for contractual discounts 65 % 65 % 66 % 67 % Provision for uncompensated care 6 % 9 % 7 % 6 %
Schedule of Net Revenue Attributable to Insurance, Medicare, Medicaid, and Self-Pay as Percentage of Net Air Medical Revenues	Net revenue attributable to Insurance, Medicare, Medicaid, and Self-Pay (expressed as a percentage of net Air Medical revenues) were as follows: Quarter Ended Nine Months Ended 2017 2016 2017 2016 Insurance 73 % 75 % 72 % 72 % Medicare 17 % 17 % 18 % 18 % Medicaid 9 % 8 % 9 % 9 % Self-Pay 1 % — % 1 % 1 %
Schedule of Financial Information Concerning Reportable Operating Segments	Summarized financial information concerning our reportable operating segments for the three and nine months ended September 30, 2017 and 2016 is as follows: Quarter Ended Nine Months Ended 2017 2016 2017 2016 (Thousands of dollars) Segment operating revenues, net Oil and Gas $ 75,700 $ 77,551 $ 222,098 $ 249,173 Air Medical 70,280 74,482 192,840 220,089 Technical Services 4,187 6,060 16,271 19,983 Total operating revenues, net 150,167 158,093 431,209 489,245 Segment direct expenses (1) Oil and Gas (2) 81,467 82,832 236,878 262,148 Air Medical 51,120 56,562 152,363 172,603 Technical Services 3,761 5,742 12,565 15,432 Total segment direct expenses 136,348 145,136 401,806 450,183 Segment selling, general and administrative expenses Oil and Gas 1,148 1,705 4,501 4,838 Air Medical 3,136 3,056 9,280 8,293 Technical Services 338 266 1,032 763 Total segment selling, general and administrative expenses 4,622 5,027 14,813 13,894 Total segment expenses 140,970 150,163 416,619 464,077 Net segment (loss) profit Oil and Gas (6,915 ) (6,986 ) (19,281 ) (17,813 ) Air Medical 16,024 14,864 31,197 39,193 Technical Services 88 52 2,674 3,788 Total net segment profit 9,197 7,930 14,590 25,168 Other, net (3) 710 377 2,471 5,425 Unallocated selling, general and administrative costs (1) (6,779 ) (8,354 ) (23,878 ) (22,938 ) Interest expense (8,027 ) (7,719 ) (24,305 ) (22,792 ) (Loss) earnings before income taxes $ (4,899 ) $ (7,766 ) $ (31,122 ) $ (15,137 ) (1) Included in direct expenses and unallocated selling, general, and administrative costs are the depreciation and amortization expense amounts below:
Depreciation and Amortization Expense Included in Direct Expenses and Unallocated Selling, General, and Administrative Costs	Depreciation and Amortization Expense Quarter Ended Nine Months Ended 2017 2016 2017 2016 (Thousands of dollars) Segment Direct Expense: Oil and Gas $ 9,615 $ 10,616 $ 29,301 $ 30,558 Air Medical 4,885 5,267 15,581 14,654 Technical Services 146 141 440 426 Total $ 14,646 $ 16,024 $ 45,322 $ 45,638 Unallocated SG&A $ 1,936 $ 2,269 $ 5,271 $ 7,416 (2) Includes Equity in (earnings) of unconsolidated affiliates, net. (3) Consists of (gains) losses on disposition of property and equipment and other income

Condensed Consolidating Finan30

Condensed Consolidating Financial Information (Tables)	9 Months Ended
	Sep. 30, 2017
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Condensed Consolidating Balance Sheets	PHI, INC. AND SUBSIDIARIES CONDENSED CONSOLIDATING BALANCE SHEETS (Thousands of dollars) (Unaudited) September 30, 2017 Parent Guarantor Non-Guarantor Subsidiaries Eliminations Consolidated ASSETS Current Assets: Cash $ 50 $ 1,071 $ 1,870 $ — $ 2,991 Short-term investments 204,036 — — — 204,036 Accounts receivable – net 77,061 71,727 14,721 (10,772 ) 152,737 Intercompany receivable — 120,376 — (120,376 ) — Inventories of spare parts – net 70,617 8,628 — — 79,245 Prepaid expenses 9,916 1,948 142 — 12,006 Deferred income taxes 10,798 — — — 10,798 Income taxes receivable 500 9 — — 509 Total current assets 372,978 203,759 16,733 (131,148 ) 462,322 Investment in subsidiaries 390,840 — — (390,840 ) — Property and equipment – net 621,885 287,841 601 — 910,327 Restricted cash and investments 12,381 — 15 — 12,396 Other assets 8,076 956 — — 9,032 Total assets $ 1,406,160 $ 492,556 $ 17,349 $ (521,988 ) $ 1,394,077 LIABILITIES AND SHAREHOLDERS’ EQUITY Current Liabilities: Accounts payable $ 26,587 $ 3,557 $ 11,235 $ (10,772 ) $ 30,607 Accrued and other current liabilities 22,198 9,961 1,544 — 33,703 Intercompany payable 112,015 — 8,361 (120,376 ) — Total current liabilities 160,800 13,518 21,140 (131,148 ) 64,310 Long-term debt 598,182 — — — 598,182 Deferred income taxes and other long-term liabilities 65,117 83,891 516 — 149,524 Shareholders’ Equity: Common stock and paid-in capital 308,634 77,951 1,375 (79,326 ) 308,634 Accumulated other comprehensive loss (244 ) — — — (244 ) Retained earnings 273,671 317,196 (5,682 ) (311,514 ) 273,671 Total shareholders’ equity 582,061 395,147 (4,307 ) (390,840 ) 582,061 Total liabilities and shareholders’ equity $ 1,406,160 $ 492,556 $ 17,349 $ (521,988 ) $ 1,394,077 PHI, INC. AND SUBSIDIARIES CONDENSED CONSOLIDATING BALANCE SHEETS (Thousands of dollars) December 31, 2016 Parent Guarantor (1) Eliminations Consolidated ASSETS Current Assets: Cash $ 36 $ 2,560 $ — $ 2,596 Short-term investments 289,806 — — 289,806 Accounts receivable – net 71,458 66,807 — 138,265 Intercompany receivable — 57,904 (57,904 ) — Inventories of spare parts – net 61,834 8,568 — 70,402 Prepaid expenses 6,990 2,269 — 9,259 Deferred income taxes 10,798 — — 10,798 Income taxes receivable 558 (18 ) — 540 Total current assets 441,480 138,090 (57,904 ) 521,666 Investment in subsidiaries and others 353,160 — (353,160 ) — Property and equipment – net 589,104 314,873 — 903,977 Restricted investments 13,023 15 — 13,038 Other assets 8,660 1,099 — 9,759 Total assets $ 1,405,427 $ 454,077 $ (411,064 ) $ 1,448,440 LIABILITIES AND SHAREHOLDERS’ EQUITY Current Liabilities: Accounts payable $ 22,744 $ 5,960 $ — $ 28,704 Accrued and other current liabilities 18,725 9,621 — 28,346 Intercompany payable 57,904 — (57,904 ) — Total current liabilities 99,373 15,581 (57,904 ) 57,050 Long-term debt 631,247 — — 631,247 Deferred income taxes and other long-term liabilities 75,029 85,336 — 160,365 Shareholders’ Equity: Common stock and paid-in capital 305,815 79,191 (79,191 ) 305,815 Accumulated other comprehensive loss (478 ) — — (478 ) Retained earnings 294,441 273,969 (273,969 ) 294,441 Total shareholders’ equity 599,778 353,160 (353,160 ) 599,778 Total liabilities and shareholders’ equity $ 1,405,427 $ 454,077 $ (411,064 ) $ 1,448,440 (1) Foreign subsidiaries represent minor subsidiaries and are included in the guarantors’ subsidiaries amounts.
Condensed Consolidating Statements of Operations	PHI, INC. AND SUBSIDIARIES CONDENSED CONSOLIDATING STATEMENTS OF OPERATIONS (Thousands of dollars) (Unaudited) For the Quarter Ended September 30, 2017 Parent Guarantor Non-Guarantor Subsidiaries Eliminations Consolidated Operating revenues, net $ 79,644 $ 70,692 $ 7,784 $ (7,953 ) $ 150,167 Expenses: Direct expenses 83,727 51,247 9,765 (7,953 ) 136,786 Selling, general and administrative expenses 8,240 3,141 24 (4 ) 11,401 Total operating expenses 91,967 54,388 9,789 (7,957 ) 148,187 (Gain) Loss on disposal of assets, net (4 ) — — — (4 ) Equity in (income) loss of unconsolidated affiliates, net 112 — (550 ) — (438 ) Operating (loss) income (12,431 ) 16,304 (1,455 ) 4 2,422 Equity in net income of consolidated subsidiaries (14,850 ) — — 14,850 — Interest expense 8,027 — — — 8,027 Other income, net (709 ) (1 ) — 4 (706 ) (7,532 ) (1 ) — 14,854 7,321 (Loss) earnings before income taxes (4,899 ) 16,305 (1,455 ) (14,850 ) (4,899 ) Income tax (benefit) expense (1,622 ) — — — (1,622 ) Net (loss) earnings $ (3,277 ) $ 16,305 $ (1,455 ) $ (14,850 ) $ (3,277 ) PHI, INC. AND SUBSIDIARIES CONDENSED CONSOLIDATING STATEMENTS OF OPERATIONS (Thousands of dollars) For the Quarter Ended September 30, 2016 Parent Guarantor (1) Eliminations Consolidated Operating revenues, net $ 79,532 $ 78,561 $ — $ 158,093 Expenses: Direct expenses 83,188 61,750 — 144,938 Selling, general and administrative expenses 10,639 3,092 (350 ) 13,381 Total operating expenses 93,827 64,842 (350 ) 158,319 Loss on disposal of assets, net 85 — — 85 Equity in loss of consolidated affiliate 198 — — 198 Operating (loss) income (14,578 ) 13,719 350 (509 ) Equity in net income of consolidated subsidiaries (8,372 ) — 8,372 — Interest expense 7,716 3 — 7,719 Other income, net (812 ) — 350 (462 ) (1,468 ) 3 8,722 7,257 (Loss) earnings before income taxes (13,110 ) 13,716 (8,372 ) (7,766 ) Income tax (benefit) expense (8,143 ) 5,344 — (2,799 ) Net (loss) earnings $ (4,967 ) $ 8,372 $ (8,372 ) $ (4,967 ) (1) Foreign subsidiaries represent minor subsidiaries and are included in the guarantors’ subsidiaries amounts. CONDENSED CONSOLIDATING STATEMENTS OF OPERATIONS (Thousands of dollars) (Unaudited) For the Nine Months Ended September 30, 2017 Parent Guarantor Non-Guarantor Subsidiaries Eliminations Consolidated Operating revenues, net $ 228,973 $ 197,022 $ 15,987 $ (10,773 ) $ 431,209 Expenses: Direct expenses 238,669 155,434 16,920 (10,773 ) 400,250 Selling, general and administrative expenses 29,265 9,296 144 (14 ) 38,691 Total operating expenses 267,934 164,730 17,064 (10,787 ) 438,941 Loss (gain) on disposal of assets, net 4 (1 ) — — 3 Equity in loss (income) of unconsolidated affiliates, net 1,040 — 516 — 1,556 Operating (loss) income (40,005 ) 32,293 (1,593 ) 14 (9,291 ) Equity in net income of consolidated subsidiaries (32,093 ) — — 32,093 — Interest expense 24,283 22 — — 24,305 Other income, net (2,486 ) (2 ) — 14 (2,474 ) (10,296 ) 20 — 32,107 21,831 (Loss) earnings before income taxes (29,709 ) 32,273 (1,593 ) (32,093 ) (31,122 ) Income tax (benefit) expense (7,911 ) (1,413 ) — — (9,324 ) Net (loss) earnings $ (21,798 ) $ 33,686 $ (1,593 ) $ (32,093 ) $ (21,798 ) PHI, INC. AND SUBSIDIARIES CONDENSED CONSOLIDATING STATEMENTS OF OPERATIONS (Thousands of dollars) For the Nine Months Ended September 30, 2016 Parent Guarantor (1) Eliminations Consolidated Operating revenues, net $ 260,766 $ 228,479 $ — $ 489,245 Expenses: Direct expenses 264,761 185,148 — 449,909 Selling, general and administrative expenses 28,914 8,766 (848 ) 36,832 Total operating expenses 293,675 193,914 (848 ) 486,741 Gain on disposal of assets, net (3,854 ) — — (3,854 ) Equity in loss of unconsolidated affiliate 274 — — 274 Operating (loss) income (29,329 ) 34,565 848 6,084 Equity in net income of consolidated subsidiaries (20,462 ) — 20,462 — Interest expense 22,762 30 — 22,792 Other income, net (2,415 ) (4 ) 848 (1,571 ) (115 ) 26 21,310 21,221 (Loss) earnings before income taxes (29,214 ) 34,539 (20,462 ) (15,137 ) Income tax (benefit) expense (19,592 ) 14,077 — (5,515 ) Net (loss) earnings $ (9,622 ) $ 20,462 $ (20,462 ) $ (9,622 ) (1) Foreign subsidiaries represent minor subsidiaries and are included in the guarantors’ subsidiaries amounts.
Condensed Consolidated Statements of Comprehensive Income (Loss)	PHI, INC. AND SUBSIDIARIES CONDENSED CONSOLIDATING STATEMENTS OF COMPREHENSIVE INCOME (LOSS) (Thousands of dollars) (Unaudited) For the Quarter Ended September 30, 2017 Parent Guarantor Non-Guarantor Subsidiaries Eliminations Consolidated Net (loss) earnings $ (3,277 ) $ 16,305 $ (1,455 ) $ (14,850 ) $ (3,277 ) Unrealized gain on short-term investments 41 — — — 41 Changes in pension plan asset and benefit obligation (24 ) — — — (24 ) Tax effect of the above-listed adjustments (8 ) — — — (8 ) Total comprehensive (loss) income $ (3,268 ) $ 16,305 $ (1,455 ) $ (14,850 ) $ (3,268 ) PHI, INC. AND SUBSIDIARIES CONDENSED CONSOLIDATING STATEMENTS OF COMPREHENSIVE INCOME (LOSS) (Thousands of dollars) For the Quarter Ended September 30, 2016 Parent Guarantor (1) Eliminations Consolidated Net (loss) earnings $ (4,967 ) $ 8,372 $ (8,372 ) $ (4,967 ) Unrealized gain on short-term investments (494 ) — — (494 ) Changes in pension plan asset and benefit obligations 1 — — 1 Tax effect of the above-listed adjustments 178 — — 178 Total comprehensive (loss) income $ (5,282 ) $ 8,372 $ (8,372 ) $ (5,282 ) (1) Foreign subsidiaries represent minor subsidiaries and are included in the guarantors’ subsidiaries amounts. PHI, INC. AND SUBSIDIARIES CONDENSED CONSOLIDATING STATEMENTS OF COMPREHENSIVE INCOME (LOSS) (Thousands of dollars) (Unaudited) For the Nine Months Ended September 30, 2017 Parent Guarantor Non-Guarantor Subsidiaries Eliminations Consolidated Net (loss) earnings $ (21,798 ) $ 33,686 $ (1,593 ) $ (32,093 ) $ (21,798 ) Unrealized gain on short-term investments 370 — — — 370 Changes in pension plan asset and benefit obligation (2 ) — — — (2 ) Tax effect of the above-listed adjustments (134 ) — — — (134 ) Total comprehensive (loss) income $ (21,564 ) $ 33,686 $ (1,593 ) $ (32,093 ) $ (21,564 ) PHI, INC. AND SUBSIDIARIES CONDENSED CONSOLIDATING STATEMENTS OF COMPREHENSIVE INCOME (LOSS) (Thousands of dollars) For the Quarter Ended September 30, 2016 Parent Guarantor (1) Eliminations Consolidated Net (loss) earnings $ (9,622 ) $ 20,462 $ (20,462 ) $ (9,622 ) Unrealized gain on short-term investments 523 — — 523 Changes in pension plan asset and benefit obligations 3 — — 3 Tax effect of the above-listed adjustments (229 ) — — (229 ) Total comprehensive (loss) income $ (9,325 ) $ 20,462 $ (20,462 ) $ (9,325 ) (1) Foreign subsidiaries represent minor subsidiaries and are included in the guarantors’ subsidiaries amounts.
Condensed Consolidating Statements of Cash Flows	PHI, INC. AND SUBSIDIARIES CONDENSED CONSOLIDATING STATEMENTS OF CASH FLOWS (Thousands of dollars) (Unaudited) For the Nine Months Ended September 30, 2017 Parent Guarantor Non-Guarantor Subsidiaries Eliminations Consolidated Net cash (used in) provided by operating activities $ (43,328 ) $ 33,670 $ 7,790 $ — $ (1,868 ) Investing activities: Purchase of property and equipment (49,227 ) — — — (49,227 ) Proceeds from asset dispositions 21 — — — 21 Purchase of short-term investments (268,525 ) — — — (268,525 ) Proceeds from sale of short-term investments 354,250 — — — 354,250 Net cash provided by (used in) investing activities 36,519 — — — 36,519 Financing activities: Proceeds from line of credit 99,150 — — — 99,150 Payments on line of credit (133,150 ) — — — (133,150 ) Repurchase of common stock (256 ) — — — (256 ) Due to/from affiliate, net 41,079 (34,699 ) (6,380 ) — — Net cash provided by (used in) financing activities 6,823 (34,699 ) (6,380 ) — (34,256 ) Increase (decrease) in cash 14 (1,029 ) 1,410 — 395 Cash, beginning of period 36 2,100 460 — 2,596 Cash, end of period $ 50 $ 1,071 $ 1,870 $ — $ 2,991 PHI, INC. AND SUBSIDIARIES CONDENSED CONSOLIDATING STATEMENTS OF CASH FLOWS (Thousands of dollars) For the Nine Months Ended September 30, 2016 Parent Guarantor (1) Eliminations Consolidated Net cash (used in) provided by operating activities $ (32,467 ) $ 25,319 $ — $ (7,148 ) Investing activities: Purchase of property and equipment (74,647 ) (303 ) — (74,950 ) Proceeds from asset dispositions 13,233 — — 13,233 Purchase of short-term investments (263,204 ) — — (263,204 ) Proceeds from sale of short-term investments 259,322 — — 259,322 Payments of deposits on aircraft (197 ) — — (197 ) Loan to unconsolidated affiliate (1,200 ) — — (1,200 ) Net cash used in investing activities (66,693 ) (303 ) — (66,996 ) Financing activities: Proceeds from line of credit 213,900 — — 213,900 Payments on line of credit (139,000 ) — — (139,000 ) Repurchase of common stock (524 ) — — (524 ) Due to/from affiliate, net 24,774 (24,774 ) — — Net cash provided by (used in) financing activities 99,150 (24,774 ) — 74,376 (Decrease) increase in cash (10 ) 242 — 232 Cash, beginning of period 46 2,361 — 2,407 Cash, end of period $ 36 $ 2,603 $ — $ 2,639 (1) Foreign subsidiaries represent minor subsidiaries and are included in the guarantors’ subsidiaries amounts.

Basis of Presentation - Additio

Basis of Presentation - Additional Information (Detail) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Income tax expense	$ (1,622)	$ (2,799)	$ (9,324)	$ (5,515)
Accounting Standards Update 2016-09 [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Deferred tax liability	1,000		1,000
Income tax expense			1,600
Retained Earnings [Member] | Accounting Standards Update 2016-09 [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Cumulative effect adjustment	$ 1,000		$ 1,000

Investments - Components of Inv

Investments - Components of Investments (Detail) - USD ($) $ in Thousands	Sep. 30, 2017	Dec. 31, 2016
Schedule of Available-for-sale Securities [Line Items]
Cost Basis	$ 219,351	$ 305,915
Unrealized Gains	3	2
Unrealized Losses	(307)	(693)
Fair Value	219,047	305,224
Investment Type [Member]
Schedule of Available-for-sale Securities [Line Items]
Cost Basis	216,721	303,521
Unrealized Gains	3	2
Unrealized Losses	(307)	(693)
Fair Value	216,417	302,830
Investment Type [Member] | Money Market Mutual Funds [Member]
Schedule of Available-for-sale Securities [Line Items]
Cost Basis	5,278	18,118
Fair Value	5,278	18,118
Investment Type [Member] | Commercial Paper [Member]
Schedule of Available-for-sale Securities [Line Items]
Cost Basis	9,423	27,906
Unrealized Losses	(10)	(39)
Fair Value	9,413	27,867
Investment Type [Member] | US Government Agencies [Member]
Schedule of Available-for-sale Securities [Line Items]
Cost Basis	13,505	13,295
Unrealized Losses	(14)	(32)
Fair Value	13,491	13,263
Investment Type [Member] | Corporate Bonds and Notes [Member]
Schedule of Available-for-sale Securities [Line Items]
Cost Basis	188,515	244,202
Unrealized Gains	3	2
Unrealized Losses	(283)	(622)
Fair Value	188,235	243,582
Deferred Compensation Plan Assets [Member]
Schedule of Available-for-sale Securities [Line Items]
Cost Basis	2,630	2,394
Fair Value	$ 2,630	$ 2,394

Investments - Additional Inform

Investments - Additional Information (Detail) - USD ($) $ in Thousands	Sep. 30, 2017	Dec. 31, 2016
Investments, Debt and Equity Securities [Abstract]
Restricted cash and investments	$ 12,396	$ 13,038

Investments - Cost and Fair Val

Investments - Cost and Fair Value of Debt Investments Based on Maturities (Detail) - USD ($) $ in Thousands	Sep. 30, 2017	Dec. 31, 2016
Available-for-sale Securities, Debt Maturities [Abstract]
Due in one year or less, Amortized Costs	$ 133,633	$ 184,587
Due within two years, Amortized Costs	77,810	100,816
Total, Amortized Costs	211,443	285,403
Due in one year or less, Fair Value	133,481	184,334
Due within two years, Fair Value	77,658	100,378
Total, Fair Value	$ 211,139	$ 284,712

Investments - Average Coupon Ra

Investments - Average Coupon Rate Percentage and the Average Days to Maturity of Debt (Detail)	9 Months Ended	12 Months Ended
	Sep. 30, 2017	Dec. 31, 2016
Commercial Paper [Member]
Schedule of Available-for-sale Securities [Line Items]
Average Coupon Rate	123.60%	100.10%
Average Days To Maturity	228 days	184 days
US Government Agencies [Member]
Schedule of Available-for-sale Securities [Line Items]
Average Coupon Rate	121.30%	97.00%
Average Days To Maturity	325 days	400 days
Corporate Bonds and Notes [Member]
Schedule of Available-for-sale Securities [Line Items]
Average Coupon Rate	171.50%	174.50%
Average Days To Maturity	295 days	318 days

Investments - Investments in Co

Investments - Investments in Continuous Unrealized Loss Position for Less Than Twelve Months (Detail) - USD ($) $ in Thousands	Sep. 30, 2017	Dec. 31, 2016
Schedule of Available-for-sale Securities [Line Items]
Fair Value	$ 121,675	$ 251,966
Unrealized Losses	(193)	(673)
Commercial Paper [Member]
Schedule of Available-for-sale Securities [Line Items]
Fair Value	9,413	27,867
Unrealized Losses	(10)	(39)
US Government Agencies [Member]
Schedule of Available-for-sale Securities [Line Items]
Fair Value	9,495	13,263
Unrealized Losses	(10)	(32)
Corporate Bonds and Notes [Member]
Schedule of Available-for-sale Securities [Line Items]
Fair Value	102,767	210,836
Unrealized Losses	$ (173)	$ (602)

Investments - Investments in 37

Investments - Investments in Continuous Unrealized Loss Position for More Than Twelve Months (Detail) - USD ($) $ in Thousands	9 Months Ended	12 Months Ended
	Sep. 30, 2017	Dec. 31, 2016
Schedule of Available-for-sale Securities [Line Items]
Fair Value	$ 81,183	$ 24,196
Unrealized Losses	(114)	(20)
US Government Agencies [Member]
Schedule of Available-for-sale Securities [Line Items]
Fair Value	3,996	0
Unrealized Losses	(4)	0
Corporate Bonds and Notes [Member]
Schedule of Available-for-sale Securities [Line Items]
Fair Value	77,187	24,196
Unrealized Losses	$ (110)	$ (20)

Revenue Recognition and Valua38

Revenue Recognition and Valuation Accounts - Additional Information (Detail) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016	Dec. 31, 2016
Valuation and Qualifying Accounts Disclosure [Line Items]
Allowance for doubtful accounts	$ 6.1		$ 6.1		$ 6
Value of services to patients who are unable to pay	1.3	$ 2.2	5.7	$ 6.9
Estimated cost of providing charity services	0.3	$ 0.5	1.3	$ 1.8
Valuation reserves related to obsolescence and slow moving inventory	18.4		18.4		17.3
Air Medical [Member]
Valuation and Qualifying Accounts Disclosure [Line Items]
Allowance for contractual discounts against outstanding accounts receivable	129.2		129.2		111.9
Allowance for uncompensated care against outstanding accounts receivable	$ 47.7		$ 47.7		$ 46.3

Revenue Recognition and Valua39

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
Valuation and Qualifying Accounts Disclosure [Line Items]
Allowance for Contractual Discounts	58.00%	56.00%
Allowance for Uncompensated Care	21.00%	23.00%

Fair Value Measurements - Summa

Fair Value Measurements - Summary of Valuation of Investments and Financial Instruments Pricing Levels (Detail) - USD ($) $ in Thousands	Sep. 30, 2017	Dec. 31, 2016
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total	$ 219,047	$ 305,224
Investment Type [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total	216,417	302,830
Investment Type [Member] | Money Market Mutual Funds [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total	5,278	18,118
Investment Type [Member] | Commercial Paper [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total	9,413	27,867
Investment Type [Member] | US Government Agencies [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total	13,491	13,263
Investment Type [Member] | Corporate Bonds and Notes [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total	188,235	243,582
Deferred Compensation Plan Assets [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total	2,630	2,394
(Level 1) [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total	7,908	20,512
(Level 1) [Member] | Investment Type [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total	5,278	18,118
(Level 1) [Member] | Investment Type [Member] | Money Market Mutual Funds [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total	5,278	18,118
(Level 1) [Member] | Deferred Compensation Plan Assets [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total	2,630	2,394
(Level 2) [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total	211,139	284,712
(Level 2) [Member] | Investment Type [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total	211,139	284,712
(Level 2) [Member] | Investment Type [Member] | Commercial Paper [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total	9,413	27,867
(Level 2) [Member] | Investment Type [Member] | US Government Agencies [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total	13,491	13,263
(Level 2) [Member] | Investment Type [Member] | Corporate Bonds and Notes [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total	$ 188,235	$ 243,582

Fair Value Measurements - Addit

Fair Value Measurements - Additional Information (Detail) - USD ($)	Sep. 30, 2017	Dec. 31, 2016	Mar. 17, 2014
Fair Value Measurements Disclosure [Line Items]
The fair value investments reclassification of assets between level 1 and level 2	$ 0	$ 0
The fair value of Senior Notes, based on quoted market prices	489,200,000	474,400,000
Fair Value, Inputs, Level 3 [Member]
Fair Value Measurements Disclosure [Line Items]
Level 3 investments	$ 0	$ 0
5.25% Senior Notes due March 15, 2019 [Member] | Senior Notes [Member]
Fair Value Measurements Disclosure [Line Items]
Interest rate on Senior Notes	5.25%		5.25%

Long Term Debt - Components of

Long Term Debt - Components of Long-term Debt (Detail) - USD ($) $ in Thousands	Sep. 30, 2017	Dec. 31, 2016
Debt Instrument [Line Items]
Principal	$ 600,000	$ 634,000
Unamortized debt issuance debt costs	1,818	2,753
5.25% Senior Notes due March 15, 2019 [Member] | Senior Notes [Member]
Debt Instrument [Line Items]
Principal	500,000	500,000
Unamortized debt issuance debt costs	1,818	2,753
Revolving Credit Facility [Member]
Debt Instrument [Line Items]
Principal	$ 100,000	$ 134,000

Long Term Debt - Components o43

Long Term Debt - Components of Long-term Debt (Additional Information) (Detail) - 5.25% Senior Notes due March 15, 2019 [Member] - Senior Notes [Member]	9 Months Ended
	Sep. 30, 2017	Mar. 17, 2014
Debt Instrument [Line Items]
Interest rate on Senior Notes	5.25%	5.25%
Senior Notes payable periods	Mar. 15, 2019

Long Term Debt - Additional Inf

Long Term Debt - Additional Information (Detail) - USD ($)	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016	Dec. 31, 2016	Mar. 17, 2014
Debt Instrument [Line Items]
Letters of credit outstanding under the facility	$ 12,300,000		$ 12,300,000		$ 13,000,000
5.25% Senior Notes due March 15, 2019 [Member] | Senior Notes [Member]
Debt Instrument [Line Items]
Interest rate on Senior Notes	5.25%		5.25%			5.25%
Maturity date of Senior notes payable			Mar. 15, 2019
Debt instrument interest rate term			Interest is payable semi-annually on March 15 and September 15 of each year.
Debt instrument redemption date			On or after March 15, 2016
Debt instrument restrictive covenants			The indenture governing the 2019 Notes (the “2019 Indenture”) contains, among other things, certain restrictive covenants, including limitations on incurring indebtedness, creating liens, selling assets and entering into certain transactions with affiliates. The covenants also limit PHI’s ability to, among other things, pay cash dividends on common stock, repurchase or redeem common or preferred equity, prepay subordinated debt and make certain investments.
Percentage of principal amount redeemed			101.00%
Interest Expense Fund [Member]
Debt Instrument [Line Items]
Periodic payment of debt interest	$ 14,300,000	$ 13,900,000	$ 29,500,000	$ 28,300,000
Revolving Credit Facility [Member]
Debt Instrument [Line Items]
Revolving credit facility, maturity date			Oct. 1, 2018
Increased Borrowing capacity	$ 150,000,000		$ 150,000,000
Revolving Credit facility, Covenants, consolidated working capital ratio	200.00%		200.00%
Revolving Credit facility, Covenants, consolidated net worth ratio	150.00%		150.00%
Revolving Credit facility, Covenants, fixed coverage ratio	110.00%		110.00%
Revolving Credit facility, Covenants, consolidated net worth	$ 450,000,000		$ 450,000,000
Letters of credit outstanding under the facility	$ 7,800,000		$ 7,800,000
Revolving Credit Facility [Member] | LIBOR [Member]
Debt Instrument [Line Items]
LIBOR plus interest rate on borrowed funds			2.25%

Earnings Per Share - Components

Earnings Per Share - Components of Basic and Diluted Earnings Per Share (Detail) - shares shares in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Weighted Average Number of Shares Outstanding Reconciliation [Abstract]
Weighted average outstanding shares of common stock, basic	15,799	15,683	15,750	15,655
Dilutive effect of unvested restricted stock units	0	0	0	0
Weighted average outstanding shares of common stock, diluted	15,799	15,683	15,750	15,655

Earnings Per Share - Componen46

Earnings Per Share - Components of Basic and Diluted Earnings Per Share (Additional Information) (Detail) - shares shares in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Weighted Average Number of Shares Outstanding Reconciliation [Abstract]
Anti-dilutive securities	0	52,126	0	22,221

Stock-Based Compensation - Summ

Stock-Based Compensation - Summary of Share Based Compensation Expense (Detail) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Stock-based compensation expense:
Total stock-based compensation expense	$ 1,271	$ 1,454	$ 3,074	$ 4,349
Time-based Restricted Units [Member]
Stock-based compensation expense:
Total stock-based compensation expense	582	631	1,678	1,847
Performance-based Restricted Units [Member]
Stock-based compensation expense:
Total stock-based compensation expense	$ 689	$ 823	$ 1,396	$ 2,502

Stock-Based Compensation - Addi

Stock-Based Compensation - Additional Information (Detail) - shares	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Time-based Restricted Units [Member]
Stock Based Compensation [Line Items]
Restricted units awarded to managers (shares)	26,296	10,992	472,913	25,280
Performance-based Restricted Units [Member]
Stock Based Compensation [Line Items]
Restricted units awarded to managers (shares)	4,646	2,318	371,045	310,481

Asset Disposals - Additional In

Asset Disposals - Additional Information (Detail) $ in Millions	3 Months Ended		6 Months Ended
	Sep. 30, 2017Aircraft	Sep. 30, 2016USD ($)Aircraft	Jun. 30, 2017Aircraft	Jun. 30, 2016USD ($)Aircraft
Assets Held For Sale And Impairments [Line Items]
Cash realized from sale of assets				$ 11
Gain (loss) on disposal of assets				$ 3.9
Light Aircraft [Member]
Assets Held For Sale And Impairments [Line Items]
Number of aircraft sold | Aircraft		4		5
Cash realized from sale of assets		$ 2.2
Gain (loss) on disposal of assets		$ 0.1
Oil and Gas [Member] | Medium Aircraft [Member]
Assets Held For Sale And Impairments [Line Items]
Number of aircraft sold | Aircraft	1		5	3

Commitments and Contingencies -

Commitments and Contingencies - Additional Information (Detail)	9 Months Ended
	Sep. 30, 2017USD ($)Land_Parcel
Long-term Purchase Commitment [Line Items]
Purchase commitment for aircraft	$ 0
Total aircraft deposits	500,000
Aggregate estimated probable liability environmental matters	$ 150,000
Number of parcels of land exists | Land_Parcel	2
Aggregate commitments under operating leases	$ 194,900,000
Operational lease payable	10,700,000
Lease commitment for aircraft	182,000,000
Facility lease commitments	12,900,000
2018 [Member]
Long-term Purchase Commitment [Line Items]
Aggregate purchase price for aircraft	127,000,000
2019 [Member]
Long-term Purchase Commitment [Line Items]
Aggregate purchase price for aircraft	129,000,000
2020 [Member]
Long-term Purchase Commitment [Line Items]
Aggregate purchase price for aircraft	$ 22,700,000

Segment Information - Additiona

Segment Information - Additional Information (Detail)	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017StatesAircraftLocationSegment	Sep. 30, 2016
Segment Reporting Information [Line Items]
Number of reportable segments | Segment			3
National Science Foundation [Member]
Segment Reporting Information [Line Items]
Number of aircraft assigned			6
Hospitals Contracts [Member]
Segment Reporting Information [Line Items]
Segment revenue	15.00%	27.00%	17.00%	29.00%
Fixed Term Customer Contract [Member]
Segment Reporting Information [Line Items]
Segment revenue	89.00%	92.00%	90.00%	92.00%
Contracted Customers [Member]
Segment Reporting Information [Line Items]
Segment revenue			10.00%	8.00%
Minimum [Member]
Segment Reporting Information [Line Items]
Term of contract			1 year
Maximum [Member]
Segment Reporting Information [Line Items]
Term of contract			7 years
Oil and Gas [Member]
Segment Reporting Information [Line Items]
Number of aircraft available for use			126
Segment revenue	50.00%	49.00%	51.00%	51.00%
Oil and Gas [Member] | Minimum [Member] | Major Customer [Member]
Segment Reporting Information [Line Items]
Working period with major customers			30 years
Oil and Gas [Member] | Minimum [Member] | ENI Petroleum [Member]
Segment Reporting Information [Line Items]
Working period with major customers			15 years
Air Medical [Member]
Segment Reporting Information [Line Items]
Segment revenue	47.00%	47.00%	45.00%	45.00%
Number of aircraft assigned			105
Number of states in which company operates aircrafts | States			18
Locations in which company operates Aircrafts | Location			72
Technical Services [Member]
Segment Reporting Information [Line Items]
Segment revenue	3.00%	4.00%	4.00%	4.00%

Segment Information - Schedule

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%

Segment Information - Schedul53

Segment Information - Schedule of Net Revenue Attributable to Insurance, Medicare, Medicaid, and Self-Pay as Percentage of Net Air Medical Revenues (Detail) - Air Medical [Member]	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Insurance [Member]
Segment Reporting Information [Line Items]
Percentage of net Air Medical revenues	73.00%	75.00%	72.00%	72.00%
Medicare [Member]
Segment Reporting Information [Line Items]
Percentage of net Air Medical revenues	17.00%	17.00%	18.00%	18.00%
Medicaid [Member]
Segment Reporting Information [Line Items]
Percentage of net Air Medical revenues	9.00%	8.00%	9.00%	9.00%
Self Pay [Member]
Segment Reporting Information [Line Items]
Percentage of net Air Medical revenues	1.00%	0.00%	1.00%	1.00%

Segment Information - Schedul54

Segment Information - Schedule of Financial Information Concerning Reportable Operating Segments (Detail) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Segment Reporting Information [Line Items]
Total operating revenues, net	$ 150,167	$ 158,093	$ 431,209	$ 489,245
Total segment direct expenses	136,786	144,938	400,250	449,909
Total segment selling, general and administrative expenses	11,401	13,381	38,691	36,832
Total net segment profit	2,422	(509)	(9,291)	6,084
Interest expense	(8,027)	(7,719)	(24,305)	(22,792)
Loss before income taxes	(4,899)	(7,766)	(31,122)	(15,137)
Reportable Operating Segments [Member]
Segment Reporting Information [Line Items]
Total operating revenues, net	150,167	158,093	431,209	489,245
Total segment direct expenses	136,348	145,136	401,806	450,183
Total segment selling, general and administrative expenses	4,622	5,027	14,813	13,894
Total segment expenses	140,970	150,163	416,619	464,077
Total net segment profit	9,197	7,930	14,590	25,168
Reportable Operating Segments [Member] | Oil and Gas [Member]
Segment Reporting Information [Line Items]
Total operating revenues, net	75,700	77,551	222,098	249,173
Total segment direct expenses	81,467	82,832	236,878	262,148
Total segment selling, general and administrative expenses	1,148	1,705	4,501	4,838
Total net segment profit	(6,915)	(6,986)	(19,281)	(17,813)
Reportable Operating Segments [Member] | Air Medical [Member]
Segment Reporting Information [Line Items]
Total operating revenues, net	70,280	74,482	192,840	220,089
Total segment direct expenses	51,120	56,562	152,363	172,603
Total segment selling, general and administrative expenses	3,136	3,056	9,280	8,293
Total net segment profit	16,024	14,864	31,197	39,193
Reportable Operating Segments [Member] | Technical Services [Member]
Segment Reporting Information [Line Items]
Total operating revenues, net	4,187	6,060	16,271	19,983
Total segment direct expenses	3,761	5,742	12,565	15,432
Total segment selling, general and administrative expenses	338	266	1,032	763
Total net segment profit	88	52	2,674	3,788
Segment Reconciling Items [Member]
Segment Reporting Information [Line Items]
Other, net	710	377	2,471	5,425
Interest expense	(8,027)	(7,719)	(24,305)	(22,792)
Corporate [Member]
Segment Reporting Information [Line Items]
Unallocated selling, general and administrative costs	$ (6,779)	$ (8,354)	$ (23,878)	$ (22,938)

Segment Information - Depreciat

Segment Information - Depreciation and Amortization Expense Included in Direct Expenses and Unallocated Selling, General, and Administrative Costs (Detail) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Reportable Operating Segments [Member]
Segment Reporting, Asset Reconciling Item [Line Items]
Depreciation and Amortization Expenses	$ 14,646	$ 16,024	$ 45,322	$ 45,638
Reportable Operating Segments [Member] | Oil and Gas [Member]
Segment Reporting, Asset Reconciling Item [Line Items]
Depreciation and Amortization Expenses	9,615	10,616	29,301	30,558
Reportable Operating Segments [Member] | Air Medical [Member]
Segment Reporting, Asset Reconciling Item [Line Items]
Depreciation and Amortization Expenses	4,885	5,267	15,581	14,654
Reportable Operating Segments [Member] | Technical Services [Member]
Segment Reporting, Asset Reconciling Item [Line Items]
Depreciation and Amortization Expenses	146	141	440	426
Corporate [Member]
Segment Reporting, Asset Reconciling Item [Line Items]
Depreciation and Amortization Expenses	$ 1,936	$ 2,269	$ 5,271	$ 7,416

Investment in Variable Intere56

Investment in Variable Interest Entity and Other Investments and Affiliates - Additional Information (Detail) - USD ($) $ in Millions	3 Months Ended			9 Months Ended
	Sep. 30, 2017	Dec. 31, 2016	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
PHI Century Limited [Member]
Variable Interest Entity [Line Items]
Investment in the common stock	49.00%			49.00%	49.00%
PHIC's date of incorporation				May 26, 2011
Earnings (loss) in equity of unconsolidated affiliate	$ 0.1		$ (0.2)	$ 1	$ 0.3
Trade receivables	3.6	$ 2		3.6
Other assets	0.4	$ 0.2		0.4
PHI-HNZ Australia Ltd [Member]
Variable Interest Entity [Line Items]
Investment in the common stock		50.00%
Earnings (loss) in equity of unconsolidated affiliate	0.5			(0.5)
Trade receivables	5.9			5.9
Other assets	$ (0.5)			$ (0.5)
HNZ Group, Inc. [Member] | PHI-HNZ Australia Ltd [Member]
Variable Interest Entity [Line Items]
Investment in the common stock		50.00%

Condensed Consolidating Finan57

Condensed Consolidating Financial Information - Additional Information (Detail) - USD ($)	Sep. 30, 2017	Mar. 17, 2014
Supplemental Guarantor Financial Information [Line Items]
Ownership percentage in domestic subsidiaries	100.00%
5.25% Senior Notes due March 15, 2019 [Member] | Senior Notes [Member]
Supplemental Guarantor Financial Information [Line Items]
Senior notes, amount issued		$ 500,000,000
Interest rate on Senior Notes	5.25%	5.25%

Condensed Consolidating Finan58

Condensed Consolidating Financial Information - Guarantor Subsidiaries - Condensed Consolidating Balance Sheets (Detail) - USD ($) $ in Thousands	Sep. 30, 2017	Dec. 31, 2016	Sep. 30, 2016	Dec. 31, 2015
Current Assets:
Cash	$ 2,991	$ 2,596	$ 2,639	$ 2,407
Short-term investments	204,036	289,806
Accounts receivable - net	152,737	138,265
Inventories of spare parts – net	79,245	70,402
Prepaid expenses	12,006	9,259
Deferred income taxes	10,798	10,798
Income taxes receivable	509	540
Total current assets	462,322	521,666
Property and equipment – net	910,327	903,977
Restricted cash and investments	12,396	13,038
Other assets	9,032	9,759
Total assets	1,394,077	1,448,440
Current Liabilities:
Accounts payable	30,607	28,704
Accrued and other current liabilities	33,703	28,346
Total current liabilities	64,310	57,050
Long-term debt	598,182	631,247
Deferred income taxes and other long-term liabilities	149,524	160,365
Shareholders’ Equity:
Common stock and paid-in capital	308,634	305,815
Accumulated other comprehensive loss	(244)	(478)
Retained earnings	273,671	294,441
Total shareholders’ equity	582,061	599,778	621,487	626,998
Total liabilities and shareholders’ equity	1,394,077	1,448,440
Eliminations [Member]
Current Assets:
Accounts receivable - net	(10,772)
Intercompany receivable	(120,376)	(57,904)
Total current assets	(131,148)	(57,904)
Investment in subsidiaries and others	(390,840)	(353,160)
Total assets	(521,988)	(411,064)
Current Liabilities:
Accounts payable	(10,772)
Intercompany payable	(120,376)	(57,904)
Total current liabilities	(131,148)	(57,904)
Shareholders’ Equity:
Common stock and paid-in capital	(79,326)	(79,191)
Retained earnings	(311,514)	(273,969)
Total shareholders’ equity	(390,840)	(353,160)
Total liabilities and shareholders’ equity	(521,988)	(411,064)
Parent Company Only (issuer) [Member]
Current Assets:
Cash	50	36	36	46
Short-term investments	204,036	289,806
Accounts receivable - net	77,061	71,458
Inventories of spare parts – net	70,617	61,834
Prepaid expenses	9,916	6,990
Deferred income taxes	10,798	10,798
Income taxes receivable	500	558
Total current assets	372,978	441,480
Investment in subsidiaries and others	390,840	353,160
Property and equipment – net	621,885	589,104
Restricted cash and investments	12,381	13,023
Other assets	8,076	8,660
Total assets	1,406,160	1,405,427
Current Liabilities:
Accounts payable	26,587	22,744
Accrued and other current liabilities	22,198	18,725
Intercompany payable	112,015	57,904
Total current liabilities	160,800	99,373
Long-term debt	598,182	631,247
Deferred income taxes and other long-term liabilities	65,117	75,029
Shareholders’ Equity:
Common stock and paid-in capital	308,634	305,815
Accumulated other comprehensive loss	(244)	(478)
Retained earnings	273,671	294,441
Total shareholders’ equity	582,061	599,778
Total liabilities and shareholders’ equity	1,406,160	1,405,427
Guarantor Subsidiaries [Member]
Current Assets:
Cash	1,071	2,100	$ 2,603	$ 2,361
Accounts receivable - net	71,727	66,807
Intercompany receivable	120,376	57,904
Inventories of spare parts – net	8,628	8,568
Prepaid expenses	1,948	2,269
Income taxes receivable	9	(18)
Total current assets	203,759	138,090
Property and equipment – net	287,841	314,873
Restricted cash and investments	0	15
Other assets	956	1,099
Total assets	492,556	454,077
Current Liabilities:
Accounts payable	3,557	5,960
Accrued and other current liabilities	9,961	9,621
Total current liabilities	13,518	15,581
Deferred income taxes and other long-term liabilities	83,891	85,336
Shareholders’ Equity:
Common stock and paid-in capital	77,951	79,191
Retained earnings	317,196	273,969
Total shareholders’ equity	395,147	353,160
Total liabilities and shareholders’ equity	492,556	454,077
Non-Guarantor Subsidiaries [Member]
Current Assets:
Cash	1,870	460
Accounts receivable - net	14,721
Prepaid expenses	142
Income taxes receivable	0
Total current assets	16,733
Property and equipment – net	601
Restricted cash and investments	15
Total assets	17,349
Current Liabilities:
Accounts payable	11,235
Accrued and other current liabilities	1,544
Intercompany payable	8,361
Total current liabilities	21,140
Deferred income taxes and other long-term liabilities	516
Shareholders’ Equity:
Common stock and paid-in capital	1,375
Retained earnings	(5,682)
Total shareholders’ equity	(4,307)
Total liabilities and shareholders’ equity	$ 17,349
Guarantor and Non-Guarantor Subsidiaries [Member]
Current Assets:
Cash		$ 2,560

Condensed Consolidating Finan59

Condensed Consolidating Financial Information - Guarantor Subsidiaries - Condensed Consolidating Statements of Operations (Detail) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Condensed Income Statements, Captions [Line Items]
Operating revenues, net	$ 150,167	$ 158,093	$ 431,209	$ 489,245
Expenses:
Direct expenses	136,786	144,938	400,250	449,909
Selling, general and administrative expenses	11,401	13,381	38,691	36,832
Total operating expenses	148,187	158,319	438,941	486,741
Gain (loss) on disposal of assets	(4)	85	3	(3,854)
Equity in loss of unconsolidated affiliate, net	(438)	198	1,556	274
Operating (loss) income	2,422	(509)	(9,291)	6,084
Equity in net income of consolidated subsidiaries				0
Interest expense	8,027	7,719	24,305	22,792
Other income, net	(706)	(462)	(2,474)	(1,571)
Total expenses	7,321	7,257	21,831	21,221
(Loss) earnings before income taxes	(4,899)	(7,766)	(31,122)	(15,137)
Income tax benefit	(1,622)	(2,799)	(9,324)	(5,515)
Net (loss) earnings	(3,277)	(4,967)	(21,798)	(9,622)
Eliminations [Member]
Condensed Income Statements, Captions [Line Items]
Operating revenues, net	(7,953)		(10,773)
Expenses:
Direct expenses	(7,953)		(10,773)	0
Selling, general and administrative expenses	(4)	(350)	(14)	(848)
Total operating expenses	(7,957)	(350)	(10,787)	(848)
Equity in loss of unconsolidated affiliate, net		0		0
Operating (loss) income	4	350	14	848
Equity in net income of consolidated subsidiaries	14,850	8,372	32,093	20,462
Interest expense				0
Other income, net	4	350	14	848
Total expenses	14,854	8,722	32,107	21,310
(Loss) earnings before income taxes	(14,850)	(8,372)	(32,093)	(20,462)
Income tax benefit				0
Net (loss) earnings	(14,850)	(8,372)	(32,093)	(20,462)
Parent Company Only (issuer) [Member]
Condensed Income Statements, Captions [Line Items]
Operating revenues, net	79,644	79,532	228,973	260,766
Expenses:
Direct expenses	83,727	83,188	238,669	264,761
Selling, general and administrative expenses	8,240	10,639	29,265	28,914
Total operating expenses	91,967	93,827	267,934	293,675
Gain (loss) on disposal of assets	(4)	85	4	(3,854)
Equity in loss of unconsolidated affiliate, net	112	198	1,040	274
Operating (loss) income	(12,431)	(14,578)	(40,005)	(29,329)
Equity in net income of consolidated subsidiaries	(14,850)	(8,372)	(32,093)	(20,462)
Interest expense	8,027	7,716	24,283	22,762
Other income, net	(709)	(812)	(2,486)	(2,415)
Total expenses	(7,532)	(1,468)	(10,296)	(115)
(Loss) earnings before income taxes	(4,899)	(13,110)	(29,709)	(29,214)
Income tax benefit	(1,622)	(8,143)	(7,911)	(19,592)
Net (loss) earnings	(3,277)	(4,967)	(21,798)	(9,622)
Guarantor Subsidiaries [Member]
Condensed Income Statements, Captions [Line Items]
Operating revenues, net	70,692	78,561	197,022	228,479
Expenses:
Direct expenses	51,247	61,750	155,434	185,148
Selling, general and administrative expenses	3,141	3,092	9,296	8,766
Total operating expenses	54,388	64,842	164,730	193,914
Gain (loss) on disposal of assets	0		(1)
Equity in loss of unconsolidated affiliate, net		0		0
Operating (loss) income	16,304	13,719	32,293	34,565
Interest expense	0	3	22	30
Other income, net	(1)	0	(2)	(4)
Total expenses	(1)	3	20	26
(Loss) earnings before income taxes	16,305	13,716	32,273	34,539
Income tax benefit	0	5,344	(1,413)	14,077
Net (loss) earnings	16,305	$ 8,372	33,686	$ 20,462
Non-Guarantor Subsidiaries [Member]
Condensed Income Statements, Captions [Line Items]
Operating revenues, net	7,784		15,987
Expenses:
Direct expenses	9,765		16,920
Selling, general and administrative expenses	24		144
Total operating expenses	9,789		17,064
Gain (loss) on disposal of assets	0		0
Equity in loss of unconsolidated affiliate, net	(550)		516
Operating (loss) income	(1,455)		(1,593)
Interest expense	0		0
Other income, net	0		0
Total expenses	0		0
(Loss) earnings before income taxes	(1,455)		(1,593)
Income tax benefit	0
Net (loss) earnings	$ (1,455)		$ (1,593)

Condensed Consolidating Finan60

Condensed Consolidating Financial Information - Guarantor Subsidiaries - Condensed Consolidated Statements of Comprehensive Income (Loss) (Detail) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Condensed Financial Statements, Captions [Line Items]
Net (loss) earnings	$ (3,277)	$ (4,967)	$ (21,798)	$ (9,622)
Unrealized gain (loss) on short-term investments	41	(494)	370	523
Changes in pension plan asset and benefit obligation	(24)	1	(2)	3
Tax effect of the above-listed adjustments	(8)	178	(134)	(229)
Total comprehensive (loss) income	(3,268)	(5,282)	(21,564)	(9,325)
Eliminations [Member]
Condensed Financial Statements, Captions [Line Items]
Net (loss) earnings	(14,850)	(8,372)	(32,093)	(20,462)
Total comprehensive (loss) income	(14,850)	(8,372)	(32,093)	(20,462)
Parent Company Only (issuer) [Member]
Condensed Financial Statements, Captions [Line Items]
Net (loss) earnings	(3,277)	(4,967)	(21,798)	(9,622)
Unrealized gain (loss) on short-term investments	41	(494)	370	523
Changes in pension plan asset and benefit obligation	(24)	1	(2)	3
Tax effect of the above-listed adjustments	(8)	178	(134)	(229)
Total comprehensive (loss) income	(3,268)	(5,282)	(21,564)	(9,325)
Guarantor Subsidiaries [Member]
Condensed Financial Statements, Captions [Line Items]
Net (loss) earnings	16,305	8,372	33,686	20,462
Total comprehensive (loss) income	16,305	$ 8,372	33,686	$ 20,462
Non-Guarantor Subsidiaries [Member]
Condensed Financial Statements, Captions [Line Items]
Net (loss) earnings	(1,455)		(1,593)
Total comprehensive (loss) income	$ (1,455)		$ (1,593)

Condensed Consolidating Finan61

Condensed Consolidating Financial Information - Guarantor Subsidiaries - Condensed Consolidating Statements of Cash Flows (Detail) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016
Condensed Cash Flow Statements, Captions [Line Items]
Net cash (used in) provided by operating activities	$ (1,868)	$ (7,148)
Investing activities:
Purchase of property and equipment	(49,227)	(74,950)
Proceeds from asset dispositions	21	13,233
Purchase of short-term investments	(268,525)	(263,204)
Proceeds from sale of short-term investments	354,250	259,322
Payments of deposits on aircraft	0	(197)
Loan to unconsolidated affiliate	0	(1,200)
Net cash provided by (used in) investing activities	36,519	(66,996)
Financing activities:
Proceeds from line of credit	99,150	213,900
Payments on line of credit	(133,150)	(139,000)
Repurchase of common stock	(256)	(524)
Net cash (used in) provided by financing activities	(34,256)	74,376
Increase (decrease) in cash	395	232
Cash, beginning of period	2,596	2,407
Cash, end of period	2,991	2,639
Parent Company Only (issuer) [Member]
Condensed Cash Flow Statements, Captions [Line Items]
Net cash (used in) provided by operating activities	(43,328)	(32,467)
Investing activities:
Purchase of property and equipment	(49,227)	(74,647)
Proceeds from asset dispositions	21	13,233
Purchase of short-term investments	(268,525)	(263,204)
Proceeds from sale of short-term investments	354,250	259,322
Payments of deposits on aircraft		(197)
Loan to unconsolidated affiliate		(1,200)
Net cash provided by (used in) investing activities	36,519	(66,693)
Financing activities:
Proceeds from line of credit	99,150	213,900
Payments on line of credit	(133,150)	(139,000)
Repurchase of common stock	(256)	(524)
Due to/from affiliate, net	41,079	24,774
Net cash (used in) provided by financing activities	6,823	99,150
Increase (decrease) in cash	14	(10)
Cash, beginning of period	36	46
Cash, end of period	50	36
Guarantor Subsidiaries [Member]
Condensed Cash Flow Statements, Captions [Line Items]
Net cash (used in) provided by operating activities	33,670	25,319
Investing activities:
Purchase of property and equipment	0	(303)
Net cash provided by (used in) investing activities	0	(303)
Financing activities:
Due to/from affiliate, net	(34,699)	(24,774)
Net cash (used in) provided by financing activities	(34,699)	(24,774)
Increase (decrease) in cash	(1,029)	242
Cash, beginning of period	2,100	2,361
Cash, end of period	1,071	$ 2,603
Non-Guarantor Subsidiaries [Member]
Condensed Cash Flow Statements, Captions [Line Items]
Net cash (used in) provided by operating activities	7,790
Investing activities:
Net cash provided by (used in) investing activities	0
Financing activities:
Due to/from affiliate, net	(6,380)
Net cash (used in) provided by financing activities	(6,380)
Increase (decrease) in cash	1,410
Cash, beginning of period	460
Cash, end of period	$ 1,870

Subsequent Event (Details)

Subsequent Event (Details)	Oct. 30, 2017CAD
Purchaser [Member] | Subsequent Event [Member]
Subsequent Event [Line Items]
Loan receivable	CAD 167,500,000
Purchaser [Member] | HNZ Group, Inc. [Member] | Subsequent Event [Member]
Subsequent Event [Line Items]
Voting interest acquired (percent)	100.00%
Scenario, Forecast [Member] | HNZ Group, Inc. [Member]
Subsequent Event [Line Items]
Fee to be received if agreement is terminated	CAD 6,500,000