Planet Fitness (PLNT) 10-K 1 Mar 18 2017 FY Annual report Financial data

Document and Entity Information

Document and Entity Information - USD ($) $ in Billions	12 Months Ended
	Dec. 31, 2017	Feb. 22, 2018	Jun. 30, 2017
Document Information [Line Items]
Document Type	10-K
Amendment Flag	false
Document Period End Date	Dec. 31, 2017
Document Fiscal Year Focus	2,017
Document Fiscal Period Focus	FY
Trading Symbol	PLNT
Entity Registrant Name	PLANET FITNESS, INC.
Entity Central Index Key	1,637,207
Current Fiscal Year End Date	--12-31
Entity Well-known Seasoned Issuer	Yes
Entity Current Reporting Status	Yes
Entity Voluntary Filers	No
Entity Filer Category	Large Accelerated Filer
Entity Public Float			$ 2
Class A Common Stock [Member]
Document Information [Line Items]
Entity Common Stock, Shares Outstanding		87,490,563
Class B Common Stock [Member]
Document Information [Line Items]
Entity Common Stock, Shares Outstanding		10,892,740

Consolidated balance sheets

Consolidated balance sheets - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Current assets:
Cash and cash equivalents	$ 113,080	$ 40,393
Accounts receivable, net of allowance for bad debts of $32 and $687 at December 31, 2017 and 2016, respectively	37,272	26,873
Due from related parties	3,020	2,864
Inventory	2,692	1,802
Restricted assets – NAF (note 4)	499	3,074
Prepaid expenses	3,929	3,591
Other receivables	9,562	7,935
Income tax receivable	6,947	4,693
Total current assets	177,001	91,225
Property and equipment, net	83,327	61,238
Intangible assets, net	235,657	253,862
Goodwill	176,981	176,981
Deferred income taxes	407,782	410,407
Other assets, net	11,717	7,729
Total assets	1,092,465	1,001,442
Current liabilities:
Current maturities of long-term debt	7,185	7,185
Accounts payable	28,648	28,507
Accrued expenses	18,590	19,190
Equipment deposits	6,498	2,170
Restricted liabilities - NAF (note 4)	490	134
Deferred revenue, current	19,083	17,780
Payable pursuant to tax benefit arrangements, current	31,062	8,072
Other current liabilities	474	235
Total current liabilities	112,030	83,273
Long-term debt, net of current maturities	696,576	702,003
Deferred rent, net of current portion	6,127	5,108
Deferred revenue, net of current portion	8,440	8,351
Deferred tax liabilities	1,629	1,238
Payable pursuant to tax benefit arrangements, net of current portion	400,298	410,999
Other liabilities	4,302	5,225
Total noncurrent liabilities	1,117,372	1,132,924
Commitments and contingencies (note 15)
Stockholders' equity:
Accumulated other comprehensive loss	(648)	(1,174)
Additional paid in capital	12,118	34,467
Accumulated deficit	(130,966)	(164,062)
Total stockholders' deficit attributable to Planet Fitness, Inc.	(119,486)	(130,759)
Non-controlling interests	(17,451)	(83,996)
Total stockholders' deficit	(136,937)	(214,755)
Total liabilities and stockholders' deficit	1,092,465	1,001,442
Class A Common Stock [Member]
Stockholders' equity:
Common stock, value	9	6
Class B Common Stock [Member]
Stockholders' equity:
Common stock, value	$ 1	$ 4

Consolidated balance sheets (Pa

Consolidated balance sheets (Parenthetical) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Accounts receivable, allowance for bad debts	$ 32	$ 687
Class A Common Stock [Member]
Common stock, par value	$ 0.0001	$ 0.0001
Common stock, shares authorized	300,000,000	300,000,000
Common stock, shares issued	87,188,000	61,314,000
Common stock, shares outstanding	87,188,000	61,314,000
Class B Common Stock [Member]
Common stock, par value	$ 0.0001	$ 0.0001
Common stock, shares authorized	100,000,000	100,000,000
Common stock, shares issued	11,193,000	37,185,000
Common stock, shares outstanding	11,193,000	37,185,000

Consolidated statements of oper

Consolidated statements of operations - USD ($) $ in Thousands		12 Months Ended
		Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Revenue:
Franchise		$ 131,983	$ 97,374	$ 71,762
Commission income		18,172	19,114	16,323
Corporate-owned stores		112,114	104,721	98,390
Equipment		167,673	157,032	144,062
Total revenue		429,942	378,241	330,537
Operating costs and expenses:
Cost of revenue		129,266	122,317	113,492
Store operations		60,657	60,121	57,485
Selling, general and administrative		60,369	50,008	55,573
Depreciation and amortization		31,761	31,502	32,158
Other (gain) loss		353	(1,369)	(273)
Total operating costs and expenses		282,406	262,579	258,435
Income from operations		147,536	115,662	72,102
Other income (expense), net:
Interest expense, net		(35,283)	(27,125)	(24,549)
Other income (expense), net		316,928	1,371	(275)
Total other income (expense), net		281,645	(25,754)	(24,824)
Income before income taxes		429,181	89,908	47,278
Provision for income taxes		373,580	18,661	9,148
Net income		55,601	71,247	38,130
Less net income attributable to non-controlling interests		22,455	49,747	19,612
Net income attributable to Planet Fitness, Inc.		$ 33,146	$ 21,500	$ 18,518
Class A Common Stock [Member]
Net income per share of Class A common stock:
Basic	[1]	$ 0.42	$ 0.50	$ 0.11
Diluted	[1]	$ 0.42	$ 0.50	$ 0.11
Weighted-average shares of Class A common stock outstanding:
Basic	[1]	78,910,390	43,300,288	36,244,000
Diluted	[1]	78,971,550	43,304,685	36,244,000
[1]	For the year ended December 31, 2015, represents earnings per share of Class A common stock and weighted-average shares of Class A common stock outstanding for the period from August 6, 2015 through December 31, 2015, the period following the recapitalization transactions and IPO (see Note 13).

Consolidated statements of comp

Consolidated statements of comprehensive income - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Statement Of Income And Comprehensive Income [Abstract]
Net income including non-controlling interests	$ 55,601	$ 71,247	$ 38,130
Other comprehensive (loss) income, net:
Unrealized gain (loss) on interest rate caps, net of tax	1,143	(78)	(1,388)
Foreign currency translation adjustments	26	(72)	314
Total other comprehensive income (loss), net	1,169	(150)	(1,074)
Total comprehensive income including non-controlling interests	56,770	71,097	37,056
Less: total comprehensive income attributable to non-controlling interests	22,707	49,560	19,557
Total comprehensive income attributable to Planet Fitness, Inc.	$ 34,063	$ 21,537	$ 17,499

Consolidated statements of cash

Consolidated statements of cash flows - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Cash flows from operating activities:
Net income	$ 55,601	$ 71,247	$ 38,130
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	31,761	31,502	32,158
Amortization of deferred financing costs	1,935	1,544	1,596
Amortization of favorable leases and asset retirement obligations	334	392	478
Amortization of interest rate caps	1,755	797	28
Deferred tax expense	372,422	15,606	6,135
Loss (gain) on re-measurement of tax benefit arrangement	(317,354)	72	(2,549)
Provision for bad debts	(19)	59	667
Gain on disposal of property and equipment	(159)	(514)	(273)
Loss on extinguishment of debt	79	606
Third party debt refinancing expense	1,021	3,001
Equity-based compensation	2,531	1,728	4,877
Changes in operating assets and liabilities:
Accounts receivable	(10,481)	(7,754)	(414)
Due from related parties	(604)	1,897	4,210
Inventory	(890)	2,755	(1,545)
Other assets and other current assets	(2,981)	(7,944)	(5,720)
Accounts payable and accrued expenses	4,210	7,428	263
Other liabilities and other current liabilities	(470)	2,747	99
Income taxes	(3,027)	(5,993)	115
Payments pursuant to tax benefit arrangements	(11,446)	(6,922)
Equipment deposits	4,328	(3,417)	(1,088)
Deferred revenue	1,276	(652)	2,994
Deferred rent	1,199	632	1,502
Net cash provided by operating activities	131,021	108,817	81,663
Cash flows from investing activities:
Additions to property and equipment	(37,722)	(15,377)	(19,488)
Proceeds from sale of property and equipment	680	683	327
Net cash used in investing activities	(37,042)	(14,694)	(19,161)
Cash flows from financing activities:
Proceeds from issuance of Class A common stock sold in initial public offering, net of underwriting discounts and commissions			156,946
Use of proceeds from issuance of Class A common stock to purchase Holdings Units			(156,946)
Proceeds from issuance of long-term debt		230,000	120,000
Proceeds from issuance of Class A common stock	480	136
Principal payments on capital lease obligations	(22)	(46)	(376)
Repayment of long-term debt	(7,185)	(5,621)	(14,800)
Payment of deferred financing and other debt-related costs	(1,278)	(5,220)	(1,698)
Premiums paid for interest rate caps	(366)		(880)
Repurchase and retirement of Class B common stock		(1,583)
Dividend paid to holders of Class A common stock		(169,282)
Dividend equivalent paid to members of Pla-Fit Holdings	(1,974)	(101,729)	(140,000)
Distributions to members of Pla-Fit Holdings	(11,358)	(31,838)	(36,486)
Net cash used in financing activities	(21,703)	(85,183)	(74,240)
Effects of exchange rate changes on cash and cash equivalents	411	23	(123)
Net increase (decrease) in cash and cash equivalents	72,687	8,963	(11,861)
Cash and cash equivalents, beginning of period	40,393	31,430	43,291
Cash and cash equivalents, end of period	113,080	40,393	31,430
Supplemental cash flow information:
Net cash paid for income taxes	3,722	7,040	2,834
Cash paid for interest	31,418	24,302	23,220
Non-cash investing activities:
Non-cash additions to property and equipment	$ 861	2,203	$ 207
Non-cash financing activities:
Non-cash dividend equivalent payments		$ 3,899

Consolidated statement of chang

Consolidated statement of changes in equity - USD ($) $ in Thousands	Total	Members' Equity [Member]	Accumulated Other Comprehensive Income (Loss) [Member]	Additional Paid-in capital [Member]	Accumulated Deficit [Member]	Non-Controlling Interests [Member]	Class A Common Stock [Member]	Class A Common Stock [Member]Common Stock [Member]	Class B Common Stock [Member]	Class B Common Stock [Member]Common Stock [Member]
Beginning balance at Dec. 31, 2014	$ 151,749	$ 146,156	$ (636)			$ 6,229
Net income including non-controlling interests	38,130
Distributions to members prior to the recapitalization transactions	(164,693)	(164,693)
Net income prior to the recapitalization transactions	14,676	14,412				264
Other comprehensive loss prior to the recapitalization transactions	(1,054)		(1,054)
Equity-based compensation expense recorded in connection with recapitalization transactions	4,525	4,525
Effect of the recapitalization transactions		$ (400)			$ 138	252		$ 3		$ 7
Effect of the recapitalization transactions, shares							26,107,000		72,603,000
Issuance of Class A common stock in IPO, net of commissions								1
Issuance of Class A common stock, shares							10,491,000
Exchanges of Class B common stock, shares exchanged									(10,491,000)
Exchanges of Class B common stock, value exchanged										(1)
Tax benefit arrangement liability and deferred taxes arising from the recapitalization transactions and IPO	(18,276)				(18,276)
Net income subsequent to the recapitalization transactions	23,454				4,106	19,348
Equity-based compensation expense	352			$ 352
Distributions paid to members of Pla-Fit Holdings subsequent to the recapitalization transactions	(11,793)					(11,793)
Other comprehensive loss subsequent to the recapitalization transactions	(20)		(20)
Other comprehensive loss	(1,074)
Ending balance at Dec. 31, 2015	(1,080)		(1,710)	352	(14,032)	14,300		4		6
Ending balance (shares) at Dec. 31, 2015							36,598,000		62,112,000
Net income including non-controlling interests	71,247				21,500	49,747
Issuance of Class A common stock, shares							1,271,146
Exchanges of Class B common stock, shares exchanged									(24,705,000)
Exchanges of Class B common stock, value exchanged						(11,475)				(2)
Equity-based compensation expense	1,728			1,749	(21)
Repurchase and retirement of Class B common stock	(1,583)			(441)	(1,142)
Repurchase and retirement of Class B common stock, shares									(222,000)
Exchanges of Class B common stock, value issued			499	10,976				2
Exchanges of Class B common stock, shares issued							24,705,000
Tax benefit arrangement liability and deferred taxes arising from secondary offerings and other exchanges	21,695			21,695
Exercise of stock options and vesting of restricted share units	136			136
Exercise of stock options and vesting of restricted share units, shares							11,000
Dividend paid to holders of Class A common stock	(169,282)				(169,282)
Dividend equivalents paid or payable	(105,628)				(1,085)	(104,543)
Distributions paid to members of Pla-Fit Holdings	(31,838)					(31,838)
Other comprehensive loss	(150)		37			(187)
Ending balance at Dec. 31, 2016	(214,755)		(1,174)	34,467	(164,062)	(83,996)		6		4
Ending balance (shares) at Dec. 31, 2016							61,314,000		37,185,000
Net income including non-controlling interests	55,601				33,146	22,455
Issuance of Class A common stock, shares							4,762,943
Exchanges of Class B common stock, shares exchanged									(25,842,000)
Exchanges of Class B common stock, value exchanged			(391)	(54,042)						(3)
Equity-based compensation expense	2,531			2,565	(34)
Repurchase and retirement of Class B common stock, shares									(150,000)
Exchanges of Class B common stock, value issued						54,433		3
Exchanges of Class B common stock, shares issued							25,842,000
Tax benefit arrangement liability and deferred taxes arising from secondary offerings and other exchanges	28,648			28,648
Exercise of stock options and vesting of restricted share units	480			480
Exercise of stock options and vesting of restricted share units, shares							32,000
Forfeiture of Dividend Equivalents	449				32	417
Distributions paid to members of Pla-Fit Holdings	(11,060)				(48)	(11,012)
Other comprehensive loss	1,169		917			252
Ending balance at Dec. 31, 2017	$ (136,937)		$ (648)	$ 12,118	$ (130,966)	$ (17,451)		$ 9		$ 1
Ending balance (shares) at Dec. 31, 2017							87,188,000		11,193,000

Business organization

Business organization	12 Months Ended
	Dec. 31, 2017
Organization Consolidation And Presentation Of Financial Statements [Abstract]
Business organization	(1) Business organization Planet Fitness, Inc. (the “Company”), through its subsidiaries, is a franchisor and operator of fitness centers, with approximately 10.6 million members and 1,518 owned and franchised locations (referred to as stores) in all 50 states, the District of Columbia, Puerto Rico, Canada, the Dominican Republic and Panama as of December 31, 2017. The Company serves as the reporting entity for its various subsidiaries that operate three distinct lines of business: • Licensing and selling franchises under the Planet Fitness trade name; • Owning and operating fitness centers under the Planet Fitness trade name; and • Selling fitness-related equipment to franchisee-owned stores. In 2012 investment funds affiliated with TSG Consumer Partners, LLC (“TSG”), purchased interests in Pla-Fit Holdings. The Company was formed as a Delaware corporation on March 16, 2015 for the purpose of facilitating an initial public offering (the “IPO”) and related transactions in order to carry on the business of Pla-Fit Holdings, LLC and its subsidiaries (“Pla-Fit Holdings”). As of August 5, 2015, in connection with the recapitalization transactions discussed below, the Company became the sole managing member and holder of 100% of the voting power of Pla-Fit Holdings. Pla-Fit Holdings owns 100% of Planet Intermediate, LLC which has no operations but is the 100% owner of Planet Fitness Holdings, LLC, a franchisor and operator of fitness centers. With respect to the Company, Pla-Fit Holdings and Planet Intermediate, LLC, each entity owns nothing other than the respective entity below it in the corporate structure and each entity has no other material operations. Initial Public Offering On August 11, 2015, the Company completed an IPO pursuant to which the Company and selling stockholders sold an aggregate of 15,525,000 shares of Class A common stock at a public offering price of $16.00 per share. The Company received $156,946 in proceeds from its sale of 10,491,055 shares of Class A common stock, net of underwriting discounts and commissions, which were used to purchase an equal number of limited liability company units (“Holdings Units”) from existing holders (“Continuing LLC Owners”) of interests in Pla-Fit Holdings, at a purchase price per unit equal to the IPO price per share of Class A common stock, net of underwriting discounts and commissions. Subsequent to the IPO and the related recapitalization transactions, the Company is a holding company whose principal asset is a controlling equity interest in Pla-Fit Holdings. As the sole managing member of Pla-Fit Holdings, the Company operates and controls all of the business and affairs of Pla-Fit Holdings, and through Pla-Fit Holdings, conducts its business. As a result, the Company consolidates Pla-Fit Holdings’ financial results and reports a non-controlling interest related to the portion of Holdings Units not owned by the Company. The recapitalization transactions are considered transactions between entities under common control. As a result, the financial statements for periods prior to the IPO and the recapitalization transactions are the financial statements of Pla-Fit Holdings as the predecessor to the Company for accounting and reporting purposes. Unless otherwise specified, “the Company” refers to both Planet Fitness, Inc. and Pla-Fit Holdings throughout the remainder of these notes. Secondary offerings In June 2016, the Company completed a secondary offering (“June Secondary Offering”) of 11,500,000 shares of its Class A common stock at a price of $16.50 per share. All of the shares sold in the June Secondary Offering were offered by certain Continuing LLC Owners and TSG AIV II-A L.P and TSG PF Co-Investors A L.P. (“Direct TSG Investors”). The Company did not receive any proceeds from the sale of shares of Class A common stock offered by the Direct TSG Investors and the participating Continuing LLC Owners. The shares sold in the June Secondary Offering consisted of (i) 3,608,840 existing shares of Class A common stock held by the Direct TSG Investors and (ii) 7,891,160 newly-issued shares of Class A common stock issued in connection with the exercise of the exchange right by the Continuing LLC Owners that participated in the June Secondary Offering. Simultaneously, and in connection with the exchange, 7,891,160 shares of Class B common stock were surrendered by the Continuing LLC Owners that participated in the June Secondary Offering and canceled. Additionally, in connection with the exchange, Planet Fitness, Inc. received 7,891,160 Holdings Units, increasing its total ownership interest in Pla-Fit Holdings. Immediately preceding the June Secondary Offering, Planet Fitness, Inc. held 100% of the voting interest and 37.1% of the economic interest of Pla-Fit Holdings and the Continuing LLC Owners held the remaining 62.9% economic interest in Pla-Fit Holdings. Immediately following the completion of the June Secondary Offering, Planet Fitness, Inc. held 100% of the voting interest and 45.1% of the economic interest of Pla-Fit Holdings and the Continuing LLC Owners held the remaining 54.9% economic interest in Pla-Fit Holdings. In September 2016, the Company completed a secondary offering (“September Secondary Offering”) of 8,000,000 shares of its Class A common stock at a price of $19.62 per share. All of the shares sold in the September Secondary Offering were offered by the Direct TSG Investors and participating Continuing LLC Owners. The Company did not receive any proceeds from the sale of shares of Class A common stock offered by the Direct TSG Investors and the Continuing LLC Owners that participating in the September Secondary Offering. The shares sold in the September Secondary Offering consisted of (i) 2,593,981 existing shares of Class A common stock held by the Direct TSG Investors and (ii) 5,406,019 newly-issued shares of Class A common stock issued in connection with the exercise of the exchange right by the Continuing LLC Owners that participated in the September Secondary offering. Simultaneously, and in connection with the exchange, 5,406,019 shares of Class B common stock were surrendered by the Continuing LLC Owners that participated in the September Secondary Offering and canceled. Additionally, in connection with the exchange, Planet Fitness, Inc. received 5,406,019 Holdings Units, increasing its total ownership interest in Pla-Fit Holdings. Immediately preceding the September Secondary Offering, Planet Fitness, Inc. held 100% of the voting interest and 45.1% of the economic interest of Pla-Fit Holdings and the Continuing LLC Owners held the remaining 54.9% economic interest in Pla-Fit Holdings. Immediately following the completion of the September Secondary Offering and as of September 30, 2016, Planet Fitness, Inc. held 100% of the voting interest and 50.6% of the economic interest of Pla-Fit Holdings and the Continuing LLC Owners held the remaining 49.4% economic interest in Pla-Fit Holdings. In November 2016, the Company completed a secondary offering (“November Secondary Offering”) of 15,000,000 shares of its Class A common stock at a price of $23.22 per share. All of the shares sold in the November Secondary Offering were offered by the Direct TSG Investors and participating Continuing LLC Owners. The Company did not receive any proceeds from the sale of shares of Class A common stock offered by the Direct TSG Investors and the Continuing LLC Owners that participating in the September Secondary Offering. The shares sold in the November Secondary Offering consisted of (i) 4,863,715 existing shares of Class A common stock held by the Direct TSG Investors and (ii) 10,136,285 newly-issued shares of Class A common stock issued in connection with the exercise of the exchange right by the Continuing LLC Owners that participated in the November Secondary offering. Simultaneously, and in connection with the exchange, 10,136,285 shares of Class B common stock were surrendered by the Continuing LLC Owners that participated in the November Secondary Offering and canceled. Additionally, in connection with the exchange, Planet Fitness, Inc. received 10,136,285 Holdings Units, increasing its total ownership interest in Pla-Fit Holdings. Immediately preceding the November Secondary Offering, Planet Fitness, Inc. held 100% of the voting interest and 51.5% of the economic interest of Pla-Fit Holdings and the Continuing LLC Owners held the remaining 48.5% economic interest in Pla-Fit Holdings. Immediately following the completion of the November Secondary Offering and as of November 22, 2016, Planet Fitness, Inc. held 100% of the voting interest and 61.8% of the economic interest of Pla-Fit Holdings and the Continuing LLC Owners held the remaining 38.2% economic interest in Pla-Fit Holdings. In March 2017, the Company completed a secondary offering (“March Secondary Offering”) of 15,000,000 shares of its Class A common stock at a price of $20.44 per share. All of the shares sold in the March Secondary Offering were offered by certain existing holders of Holdings Units and the Direct TSG Investors. The Company did not receive any proceeds from the sale of shares of Class A common stock offered by the Direct TSG Investors and the participating holders of Holdings Units. The shares sold in the March Secondary Offering consisted of (i) 4,790,758 existing shares of Class A common stock held by the Direct TSG Investors and (ii) 10,209,242 newly-issued shares of Class A common stock issued in connection with the exercise of the exchange right by the holders of Holdings Units that participated in the March Secondary Offering. Simultaneously, and in connection with the exchange, 10,209,242 shares of Class B common stock were surrendered by the holders of Holdings Units that participated in the March Secondary Offering and canceled. Additionally, in connection with the exchange, Planet Fitness, Inc. received 10,209,242 Holdings Units, increasing its total ownership interest in Pla-Fit Holdings. In May 2017, the Company completed a secondary offering (“May Secondary Offering”) of 16,085,510 shares of its Class A common stock at a price of $20.28 per share. All of the shares sold in the May Secondary Offering were offered by certain existing holders of Holdings Units and the Direct TSG Investors. The Company did not receive any proceeds from the sale of shares of Class A common stock offered by the Direct TSG Investors and the participating holders of Holdings Units. The shares sold in the May Secondary Offering consisted of (i) 5,215,691 existing shares of Class A common stock held by the Direct TSG Investors and (ii) 10,869,819 newly-issued shares of Class A common stock issued in connection with the exercise of the exchange right by the holders of Holdings Units that participated in the May Secondary Offering. Simultaneously, and in connection with the exchange, 10,869,819 shares of Class B common stock were surrendered by the holders of Holdings Units that participated in the May Secondary Offering and canceled. Additionally, in connection with the exchange, Planet Fitness, Inc. received 10,869,819 Holdings Units, increasing its total ownership interest in Pla-Fit Holdings. In addition to the secondary offering transactions described above, during the years ended December 31, 2017 and 2016, certain Continuing LLC Owners have exercised their exchange rights and exchanged 4,762,943 and 1,271,146 Holdings Units, respectively, for 4,762,943 and 1,271,146 newly-issued shares of Class A common stock, respectively. Simultaneously, and in connection with these exchanges, 4,762,943 and 1,271,146 shares of Class B common stock were surrendered by the Continuing LLC Owners that exercised their exchange rights and canceled during the years ended December 31, 2017 and 2016, respectively. Additionally, in connection with these exchanges, Planet Fitness, Inc. received 4,762,943 and 1,271,146 Holdings Units during the years ended December 31, 2017 and 2016, respectively, increasing its total ownership interest in Pla-Fit Holdings. As of December 31, 2017, the Company held 100% of the voting interest, and approximately 88.6% of the economic interest in Pla-Fit Holdings and the Continuing LLC Owners held the remaining 11.4% economic interest in Pla-Fit Holdings. As future exchanges of Holdings Units occur, the economic interest in Pla-Fit Holdings held by Planet Fitness, Inc. will increase.

Summary of significant accounti

Summary of significant accounting policies	12 Months Ended
	Dec. 31, 2017
Accounting Policies [Abstract]
Summary of significant accounting policies	(2) Summary of significant accounting policies (a) Basis of presentation and consolidation The accompanying consolidated financial statements have been prepared in accordance with accounting principles generally accepted in the United States of America (“U.S. GAAP”) and pursuant to the rules and regulations of the Securities and Exchange Commission (the “SEC”). All significant intercompany balances and transactions have been eliminated in consolidation. As discussed in Note 1, as a result of the recapitalization transactions, Planet Fitness, Inc. consolidates Pla-Fit Holdings and Pla-Fit Holdings is considered to be the predecessor to Planet Fitness, Inc. for accounting and reporting purposes. The Company also consolidates entities in which it has a controlling financial interest, the usual condition of which is ownership of a majority voting interest. The Company also considers for consolidation certain interests where the controlling financial interest may be achieved through arrangements that do not involve voting interests. Such an entity, known as a variable interest entity (“VIE”), is required to be consolidated by its primary beneficiary. The primary beneficiary of a VIE is considered to possess the power to direct the activities of the VIE that most significantly impact its economic performance and has the obligation to absorb losses or the rights to receive benefits from the VIE that are significant to it. The principal entities in which the Company possesses a variable interest include franchise entities and certain other entities. The Company is not deemed to be the primary beneficiary for Planet Fitness franchise entities. Therefore, these entities are not consolidated. The results of the Company have been consolidated with Matthew Michael Realty LLC (“MMR”) and PF Melville LLC (“PF Melville”) based on the determination that the Company is the primary beneficiary with respect to these VIEs. These entities are real estate holding companies that derive a majority of their financial support from the Company through lease agreements for corporate stores. See Note 3 for further information related to the Company’s VIEs. (b) Use of estimates The preparation of financial statements in conformity with U.S. GAAP requires management to make estimates and assumptions that affect the amounts reported in the consolidated financial statements and accompanying notes. Although these estimates are based on management’s knowledge of current events and actions it may undertake in the future, they may ultimately differ from actual results. Significant areas where estimates and judgments are relied upon by management in the preparation of the consolidated financial statements include revenue recognition, valuation of equity-based compensation awards, the evaluation of the recoverability of goodwill and long-lived assets, including intangible assets, income taxes, including deferred tax assets and liabilities and reserves for unrecognized tax benefits, and the liability for the Company’s tax benefit arrangements. (c) Concentrations Cash and cash equivalents are financial instruments, which potentially subject the Company to a concentration of credit risk. The Company invests its excess cash in several major financial institutions, which are insured by the Federal Deposit Insurance Corporation (FDIC) up to $250,000. The Company maintains balances in excess of these limits, but does not believe that such deposits with its banks are subject to any unusual risk. The credit risk associated with trade receivables is mitigated due to the large number of customers, generally our franchisees, and their broad dispersion over many different geographic areas. We do not have any concentrations with respect to our revenues. The Company purchases equipment, both for corporate-owned stores and for sales to franchisee-owned stores from various equipment vendors. For the year ended December 31, 2017 purchases from one equipment vendor comprised 91% of total equipment purchases. For the year ended December 31, 2016 purchases from two equipment vendors comprised 83% and 13%, respectively, of total equipment purchases and for the year ended December 31, 2015 purchases from two equipment vendors comprised 79% and 18%, respectively, of total equipment purchases. The Company, including Planet Fitness NAF, LLC (“NAF”) uses one primary vendor for advertising services. For the year ended December 31, 2017, purchases from this vendor comprised 63% of total equipment purchases. For the year ended December 31, 2016 purchases from two vendors comprised 25% and 16%, respectively, of total advertising purchases and for the year ended December 31, 2015 purchases from one vendor comprised 49% of total advertising purchases (see Note 4 for further discussion of NAF). (d) Cash and cash equivalents The Company considers all highly liquid investments purchased with an original maturity of 90 days or less to be cash equivalents. Cash held within the NAF is recorded as a restricted asset (see Note 4). (e) Revenue recognition Franchise revenue The following revenues are generated as a result of transactions with or related to the Company’s franchisees. Area development fees Franchisees contractually enter into area development agreements (ADAs) to secure the exclusive right to open franchise stores within a defined geographical area. ADAs establish the timing and number of stores to be developed within the defined geographical area. Pursuant to an ADA, a franchisee is generally required to pay an initial nonrefundable development fee for a minimum number of stores to be developed, as outlined in the respective ADA. ADA fees collected in advance are deferred until the Company provides substantially all required obligations pursuant to the ADA. As the efforts and total cost relating to initial services are affected significantly by the number of stores opened in an area, the respective ADA is treated as a divisible contract. As each new site is accepted under an ADA, a franchisee signs a franchise operating agreement for the respective franchise location. As each store opened under an ADA typically has performance obligations associated with it, the Company recognizes ADA revenue as each individual franchise location is developed in proportion to the total number of stores to be developed under the ADA. These obligations are typically completed once the store is opened or the franchisee executes the individual property lease. As of December 31, 2017 and 2016, the deferred revenue for ADAs was $10,121 and $10,026, respectively. ADAs generally have an initial term equal to the number of years over which the franchisee is required to open franchise stores, which is typically 5 to 10 years. There is no right of refund for an executed ADA. Upon default, as defined in the agreement, the Company may reacquire the rights pursuant to an ADA, and all remaining deferred revenue is recognized at that time. Franchise fees and performance fees The Company generally charges an initial upfront nonrefundable franchise fee. Nonrefundable franchise fees are typically deferred until the franchisee executes a lease and receives initial training for the location, which is the point at which the Company has determined it has provided all of its material obligations required to recognize revenue. As of December 31, 2017 and 2016, the Company has recorded deferred franchise fees of $510 and $260, respectively, relating to stores to be opened in future years. These amounts are included in deferred revenue as of December 31, 2017 and 2016. The individual franchise agreements typically have a 10-year initial term, but provide the franchisee with an opportunity to enter into successive renewals subject to certain conditions. Transfer fees The Company’s current franchise agreement provides that upon the transfer of a Planet Fitness store to a different franchisee, the Company is entitled to a transfer fee in the amount of the greater of $25, or $10 per store being transferred, if more than one, in addition to reimbursement of out-of-pocket expenses, including external legal and administrative costs incurred in connection with the transfer. Transfer-related fees and expenses are due, payable, and recognized at the time the transfer is effectuated. Royalties Royalties, which represent recurring fees paid by franchisees based on the franchisee-owned stores’ monthly and annual membership billings, are recognized on a monthly basis over the term of the franchise agreement. As specified under certain franchise agreements, the Company recognizes additional royalty fees as the franchisee-owned stores attain contractual monthly membership billing threshold amounts. Beginning in 2010, for all new franchise agreements entered into pursuant to a newly executed ADA or outside an ADA, the Company began charging a fixed royalty percentage based upon gross membership billings. Other fees Online member join fees are paid to the Company by franchisees for processing new membership transactions when a new member signs up for a membership to a franchisee-owned store through the Company’s website. Billing transaction fees are paid to the Company for the processing of franchisee membership dues and annual fees through the Company’s third-party hosted point-of-sale system. Placement The Company is generally responsible for assembly and placement of equipment it sells to U.S. based franchisee-owned stores. Placement revenue is recognized upon completion and acceptance of the services at the franchise location. Commission income The Company recognizes commission income from its franchisees’ use of certain preferred vendor arrangements. Commissions are recognized when amounts have been earned and collectability from the vendor is reasonably assured. Corporate-owned stores revenue The following revenues are generated from stores owned and operated by the Company. Membership dues revenue Customers are offered multiple membership choices varying in length. Membership dues are earned and recognized over the membership term on a straight-line basis. Enrollment fee revenue Enrollment fees are charged to new members at the commencement of their membership. The Company recognizes enrollment fees ratably over the estimated duration of the membership life, which is generally two years. Annual membership fee revenue Annual membership fees are annual fees charged to members in addition to and in order to maintain low monthly membership dues. The Company recognizes annual membership fees ratably over the 12-month membership period. Retail sales The Company sells Planet Fitness branded apparel, food, beverages, and other accessories. The revenue for these items is recognized at the point of sale. Equipment revenue The Company sells and delivers equipment purchased from third-party equipment manufacturers to U.S. based franchisee-owned stores. Equipment revenue is recognized upon the equipment being delivered to and assembled at each store and accepted by the franchisee. Franchisees are charged for all freight costs incurred for the delivery of equipment. Freight revenue is recorded within equipment revenue and freight costs are recorded within cost of revenue. The Company recognizes revenue on a gross basis in these transactions as management has determined the Company to be the principal in these transactions. Management determined the Company to be the principal because the Company is the primary obligor in these transactions, the Company has latitude in establishing prices for the equipment sales to franchisees, the Company has supplier selection discretion and is involved in determination of product specifications, and the Company bears all credit risk associated with obligations to the equipment manufacturers. Equipment deposits are recognized as a liability on the accompanying consolidated balance sheets until delivery, assembly (if required), and acceptance by the franchisee. As of December 31, 2017 and 2016, equipment deposits were $6,498 and $2,170, respectively. Sales tax All revenue amounts are recorded net of applicable sales tax. (f) Deferred revenue Deferred revenue represents cash received from franchisees for ADAs and franchise fees for which revenue recognition criteria has not yet been met and cash received from members for enrollment fees, membership dues and annual fees for the portion not yet earned based on the membership period. (g) Cost of revenue Cost of revenue consists of direct costs associated with equipment sales (including freight costs), the cost of retail merchandise sold in corporate-owned stores, and prior to 2016 also included direct costs related to the maintenance and support of the Company’s proprietary system-wide point-of-sale system. Costs related to the point-of-sale system were $0, $0, and $1,236 for the years ended December 31, 2017, 2016 and 2015 respectively. Costs related to retail merchandise sales were immaterial in all periods presented. Rebates from equipment vendors where the Company has recognized the related equipment revenue and costs are recorded as a reduction to the cost of revenue. (h) Store operations Store operations consists of the direct costs related to operating corporate-owned stores, including our store management and staff, rent expense, utilities, supplies, maintenance, and local advertising. (i) Selling, general and administrative Selling, general and administrative expenses consist of costs associated with administrative and franchisee support functions related to our existing business as well as growth and development activities. These costs primarily consist of payroll, IT related, marketing, legal and accounting expenses. These expenses include costs related to placement services of $4,601, $3,974, and $3,452, for the years ended December 31, 2017, 2016 and 2015, respectively. (j) Accounts receivable Accounts receivable is primarily comprised of amounts owed to the Company resulting from equipment, placement, and commission revenue. The Company evaluates its accounts receivable on an ongoing basis and may establish an allowance for doubtful accounts based on collections and current credit conditions. Accounts are written off as uncollectible when it is determined that further collection efforts will be unsuccessful. Historically, the Company has not had a significant amount of write-offs. (k) Leases and asset retirement obligations The Company recognizes rent expense related to leased office and operating space on a straight-line basis over the term of the lease. The difference between rent expense and rent paid, if any, as a result of escalation provisions and lease incentives, such as tenant improvements provided by lessors, and is recorded as deferred rent in the Company’s consolidated balance sheets. In accordance with ASC Topic 410, Asset Retirement and Environmental Obligations (l) Property and equipment Property and equipment is recorded at cost and depreciated using the straight-line method over its related estimated useful life. Leasehold improvements are amortized over the shorter of the lease term or the estimated useful life of the related asset, whichever is shorter. Upon sale or retirement, the asset cost and related accumulated depreciation are removed from the respective accounts, and any related gain or loss is reflected in the consolidated statements of operations. Ordinary maintenance and repair costs are expensed as incurred. The estimated useful lives of the Company’s fixed assets by class of asset are as follows: Years Buildings and building improvements 20–40 Computers and equipment 3-5 Furniture and fixtures 5 Leasehold improvements Useful life or term of lease whichever is shorter Fitness equipment 5–7 Vehicles 5 (m) Advertising expenses The Company expenses advertising costs as incurred. Advertising expenses, net of amounts reimbursed by franchisees, are included within store operations and selling, general and administrative expenses and totaled $9,906, $8,270, and $9,349 for the years ended December 31, 2017, 2016 and 2015, respectively. See Note 4 for discussion of the national advertising fund. (n) Goodwill, long-lived assets, and other intangible assets Goodwill and other intangible assets that arise from acquisitions are recorded in accordance with ASC Topic 350, Intangibles—Goodwill and Other Goodwill and indefinite-lived intangible assets are not amortized, but are reviewed annually for impairment or more frequently if impairment indicators arise. Separable intangible assets that are not deemed to have an indefinite life are amortized over their estimated useful lives on either a straight-line or accelerated basis as deemed appropriate, and are reviewed for impairment when events or circumstances suggest that the assets may not be recoverable. The Company performs its annual test for impairment of goodwill and indefinite lived intangible assets on December 31 of each year. For goodwill, the first step of the impairment test is to determine whether the carrying amount of a reporting unit exceeds the fair value of the reporting unit. If the carrying amount of the reporting unit exceeds the reporting unit’s fair value, the Company would be required to perform a second step of the impairment test as this is an indication that the reporting unit’s goodwill may be impaired. The second step compares the implied fair value of the reporting unit’s goodwill with the carrying amount of that goodwill. Any impairment loss would be recognized in an amount equal to the excess of the carrying value of the goodwill over the implied fair value of the goodwill. The Company is also permitted to make a qualitative assessment of whether it is more likely than not that a reporting unit’s fair value is less than its carrying amount before applying the two-step goodwill impairment test. If the Company concludes it is not more likely than not that the fair value of a reporting unit is less than its carrying amount, it need not perform the two-step impairment test. For indefinite lived intangible assets, the impairment assessment consists of comparing the carrying value of the asset to its estimated fair value. To the extent that the carrying value exceeds the fair value of the asset, an impairment is recorded to reduce the carrying value to its fair value. The Company is also permitted to make a qualitative assessment of whether it is more likely than not an indefinite lived intangible asset’s fair value is less than its carrying value prior to applying the quantitative assessment. If based on the Company’s qualitative assessment it is not more likely than not that the carrying value of the asset is less than its fair value, then a quantitative assessment is not required. The Company determined that no impairment charges were required during any periods presented. The Company applies the provisions of ASC Topic 360, Property, Plant and Equipment (o) Income taxes The Company accounts for income taxes using the asset and liability method. Deferred income taxes are recognized for the expected future tax consequences attributable to temporary differences between the carrying amount of the existing tax assets and liabilities and their respective tax basis. Deferred tax assets and liabilities are measured using enacted tax rates expected to be applied in the years in which temporary differences are expected to be recovered or settled. The principal items giving rise to temporary differences are the use of accelerated depreciation and certain basis differences resulting from acquisitions and the recapitalization transactions. Valuation allowances are established when necessary to reduce deferred tax assets to the amount expected to be realized. As a result of the recapitalization transactions, Planet Fitness, Inc. became the sole managing member of Pla-Fit Holdings, which is treated as a partnership for U.S. federal and most applicable state and local income tax purposes. As a partnership, Pla-Fit Holdings is not subject to U.S. federal and certain state and local income taxes. Any taxable income or loss generated by Pla-Fit Holdings is passed through to and included in the taxable income or loss of its members, including Planet Fitness, Inc. following the recapitalization transactions, on a pro rata basis. Planet Fitness, Inc. is subject to U.S. federal income taxes, in addition to state and local income taxes with respect to our allocable share of any taxable income of Pla-Fit Holdings following the recapitalization transactions. The Company is also subject to taxes in foreign jurisdictions. The Company recognizes the effect of income tax positions only if those positions are more likely than not to be sustained. Recognized income tax positions are measured at the largest amount that is greater than 50% likely of being realized. Changes in recognition or measurement are reflected in the period in which the change in judgment occurs (see Note 14). (p) Tax benefit arrangements The Company’s acquisition of Holdings Units in connection with the IPO and future and certain past exchanges of Holdings Units for shares of the Company’s Class A common stock (or cash at the option of the Company) are expected to produce and have produced favorable tax attributes. In connection with the IPO, the Company entered into two tax receivable agreements. Under the first of those agreements, the Company generally is required to pay to certain existing and previous equity owners of Pla-Fit Holdings, LLC who are unaffiliated with TSG (the “TRA Holders”) 85% of the applicable tax savings, if any, in U.S. federal and state income tax that the Company is deemed to realize as a result of certain tax attributes of their Holdings Units sold to the Company (or exchanged in a taxable sale) and that are created as a result of (i) the sales of their Holdings Units for shares of Class A common stock and (ii) tax benefits attributable to payments made under the tax receivable agreement (including imputed interest). Under the second tax receivable agreement, the Company generally is required to pay to the Direct TSG Investors 85% of the amount of tax savings, if any, that the Company is deemed to realize as a result of the tax attributes of the Holdings Units held in respect of the Direct TSG Investors’ interest in the Company, which resulted from the Direct TSG Investors’ purchase of interests in Pla-Fit Holdings in 2012, and certain other tax benefits. Under both agreements, the Company generally retains the benefit of the remaining 15% of the applicable tax savings. Also, pursuant to the exchange agreement, to the extent an exchange results in Pla-Fit Holdings, LLC incurring a current tax liability relating to the New Hampshire business profits tax, the TRA Holders have agreed that they will contribute to Pla-Fit Holdings, LLC an amount sufficient to pay such tax liability (up to 3.5% of the value received upon exchange). If and when the Company subsequently realizes a related tax benefit, Pla-Fit Holdings, LLC will distribute the amount of any such tax benefit to the relevant Continuing LLC Owner in respect of its contribution. Due to changes in New Hampshire tax law, the Company no longer expects to incur any such liability under the New Hampshire business profits tax. Based on current projections, the Company anticipates having sufficient taxable income to utilize these tax attributes and receive corresponding tax deductions in future periods. Accordingly, as of December 31, 2017 the Company has recorded a liability of $431,360, which includes the impact of remeasurement related to the 2017 Tax Act, payable (q) Fair value ASC 820, Fair Value Measurements and Disclosures Level 1—Inputs to the valuation methodology are quoted prices (unadjusted) for identical assets or liabilities in active markets. Level 2—Inputs to the valuation methodology include quoted prices for similar assets and liabilities in active markets, and inputs that are observable for the asset or liability, either directly or indirectly, for substantially the full term of the financial instrument. Level 3—Inputs to the valuation methodology are unobservable and significant to the fair value measurement. The table below presents information about the Company’s assets and liabilities that are measured at fair value on a recurring basis as of December 31, 2017 and December 31, 2016: Quoted prices Significant Significant Total fair value at in active markets other observable unobservable December 31, 2017 markets (Level 1) inputs (Level 2) inputs (Level 3) Interest rate caps $ 340 $ — $ 340 $ — Quoted prices Significant Significant Total fair value at in active markets other observable unobservable December 31, 2016 markets (Level 1) inputs (Level 2) inputs (Level 3) Interest rate caps $ 306 $ — $ 306 $ — (r) Financial instruments The carrying values of cash and cash equivalents, accounts receivable and accounts payable approximate fair value because of the short-term nature of these instruments. The carrying value of debt also approximates fair value as it is variable rate debt. (s) Derivative instruments and hedging activities The Company recognizes all derivative instruments as either assets or liabilities in the balance sheet at their respective fair values. For derivatives designated in hedging relationships, changes in the fair value are either offset through earnings against the change in fair value of the hedged item attributable to the risk being hedged or recognized in accumulated other comprehensive income, to the extent the derivative is effective at offsetting the changes in cash flows being hedged until the hedged item affects earnings. The Company only enters into derivative contracts that it intends to designate as a hedge of a forecasted transaction or the variability of cash flows to be received or paid related to a recognized asset or liability (cash flow hedge). For all hedging relationships, the Company formally documents the hedging relationship and its risk-management objective and strategy for undertaking the hedge, the hedging instrument, the hedged transaction, the nature of the risk being hedged, how the hedging instrument’s effectiveness in offsetting the hedged risk will be assessed prospectively and retrospectively, and a description of the method used to measure ineffectiveness. The Company also formally assesses, both at the inception of the hedging relationship and on an ongoing basis, whether the derivatives that are used in hedging relationships are highly effective in offsetting changes in cash flows of hedged transactions. For derivative instruments that are designated and qualify as part of a cash flow hedging relationship, the effective portion of the gain or loss on the derivative is reported as a component of other comprehensive income and reclassified into earnings in the same period or periods during which the hedged transaction affects earnings. Gains and losses on the derivative representing either hedge ineffectiveness or hedge components excluded from the assessment of effectiveness are recognized in current earnings. See Note 8 for further information. (t) Equity-based compensation The Company has an equity-based compensation plan under which it receives services from employees and directors as consideration for equity instruments of the Company. The compensation expense is determined based on the fair value of the award as of the grant date. Compensation expense is recognized over the vesting period, which is the period over which all of the specified vesting conditions are satisfied. For awards with graded vesting, the fair value of each tranche is recognized over its respective vesting period. The Company accounts for forfeitures as they occur by reversing compensation cost when the award is forfeited. See Note 12 for further information. (u) Guarantees The Company, as a guarantor, is required to recognize, at inception of the guaranty, a liability for the fair value of the obligation undertaken in issuing the guarantee. See Notes 3 and 15 for further discussion of such obligations guaranteed. (v) Contingencies The Company records estimated future losses related to contingencies when such amounts are probable and estimable. The Company includes estimated legal fees related to such contingencies as part of the accrual for estimated future losses. (w) Reclassifications Certain amounts have been reclassified to conform to current year presentation. (x) Recent accounting pronouncements The FASB issued ASU No. 2014-09, Revenue from Contracts with Customers, The FASB issued ASU No. 2016-02, Leases The FASB issued ASU No. 2016-09, Stock Compensation The FASB issued ASU No. 2016-15, Classification of Certain Cash Receipts and Cash Payments The FASB issued ASU No. 2017-04, Simplifying the Test for Goodwill Impairment The FASB issued ASU No. 2017-12, Targeted Improvements to Accounting for Hedging Activities

Variable interest entities

Variable interest entities	12 Months Ended
	Dec. 31, 2017
Organization Consolidation And Presentation Of Financial Statements [Abstract]
Variable interest entities	(3) Variable interest entities The carrying values of VIEs included in the consolidated financial statements as of December 31, 2017 and December 31, 2016 are as follows: December 31, 2017 December 31, 2016 Assets Liabilities Assets Liabilities PF Melville $ 4,420 $ — $ 4,071 $ — MMR $ 3,360 — $ 3,156 — Total $ 7,780 $ — $ 7,227 $ — The Company also has variable interests in certain franchisees mainly through the guarantee of certain debt and lease agreements as well as financing provided by the Company and by certain related parties to franchisees. The Company’s maximum obligation, as a result of its guarantees of leases and debt, is approximately $979 and $1,350 as of December 31, 2017 and 2016, respectively. The amount of the Company’s maximum obligation represents a loss that the Company could incur from the variability in credit exposure without consideration of possible recoveries through insurance or other means. In addition, the amount bears no relation to the ultimate settlement anticipated to be incurred from the Company’s involvement with these entities, which is estimated at $0.

National advertising fund

National advertising fund	12 Months Ended
	Dec. 31, 2017
Related Party Transactions [Abstract]
National advertising fund	(4) National advertising fund On July 26, 2011, the Company established Planet Fitness NAF, LLC (“NAF”) for the creation and development of marketing, advertising, and related programs and materials for all Planet Fitness stores located in the United States and Puerto Rico. On behalf of the NAF, the Company collects 2% of gross monthly membership billings from franchisees, in accordance with the provisions of the franchise agreements. The Company also contributes 2% of monthly membership billings from stores owned by the Company to the NAF. The use of amounts received by NAF is restricted to advertising, product development, public relations, merchandising, and administrative expenses and programs to increase sales and further enhance the public reputation of the Planet Fitness brand. The Company consolidates and reports all assets and liabilities held by the NAF within the consolidated financial statements. Amounts received or receivable by NAF are reported as restricted assets and restricted liabilities within current assets and current liabilities on the consolidated balance sheets. The Company provides administrative services to NAF and charges NAF a fee for providing those services. These services include accounting services, information technology, data processing, product development, legal and administrative support, and other operating expenses, which amounted $2,150, $1,700 and $1,340 for the years ended December 31, 2017, 2016 and 2015, respectively. The fees paid to the Company by NAF are included in the consolidated statements of operations as a reduction in general and administrative expense, where the expense incurred by the Company was initially recorded.

Property and equipment

Property and equipment	12 Months Ended
	Dec. 31, 2017
Property Plant And Equipment [Abstract]
Property and equipment	(5) Property and equipment Property and equipment as of December 31, 2017 and 2016 consists of the following: December 31, 2017 December 31, 2016 Land $ 910 $ 910 Equipment 32,403 27,283 Leasehold improvements 60,181 41,249 Buildings and improvements 5,107 5,107 Furniture & fixtures 9,790 3,708 Other 7,923 5,673 Construction in progress 3,241 8,295 119,555 92,225 Accumulated Depreciation (36,228 ) (30,987 ) Total $ 83,327 $ 61,238 The Company recorded depreciation expense of $13,886, $12,131, and $11,088 for the years ended December 31, 2017, 2016 and 2015, respectively.

Goodwill and intangible assets

Goodwill and intangible assets	12 Months Ended
	Dec. 31, 2017
Goodwill And Intangible Assets Disclosure [Abstract]
Goodwill and intangible assets	(6) Goodwill and intangible assets A summary of goodwill and intangible assets at December 31, 2017 and 2016 is as follows: Weighted average Gross amortization carrying Accumulated Net carrying December 31, 2017 period (years) amount amortization Amount Customer relationships 11.1 $ 171,782 (86,501 ) $ 85,281 Noncompete agreements 5.0 14,500 (14,500 ) — Favorable leases 7.5 2,935 (1,972 ) 963 Order backlog 0.4 3,400 (3,400 ) — Reacquired franchise rights 5.8 8,950 (5,837 ) 3,113 201,567 (112,210 ) 89,357 Indefinite-lived intangible: Trade and brand names N/A 146,300 — 146,300 Total intangible assets $ 347,867 $ (112,210 ) $ 235,657 Goodwill $ 176,981 $ — $ 176,981 Weighted average Gross amortization carrying Accumulated Net carrying December 31, 2016 period (years) amount amortization Amount Customer relationships 11.1 $ 171,782 (72,655 ) $ 99,127 Noncompete agreements 5.0 14,500 (12,027 ) 2,473 Favorable leases 7.5 2,935 (1,643 ) 1,292 Order backlog 0.4 3,400 (3,400 ) — Reacquired franchise rights 5.8 8,950 (4,280 ) 4,670 201,567 (94,005 ) 107,562 Indefinite-lived intangible: Trade and brand names N/A 146,300 — 146,300 Total intangible assets $ 347,867 $ (94,005 ) $ 253,862 Goodwill $ 176,981 $ — $ 176,981 There were no changes in the carrying amount of goodwill during the years ended December 31, 2017 or 2016. The Company determined that no impairment charges were required during any periods presented. Amortization expense related to the intangible assets totaled $18,205, $19,757, and $21,543 for the years ended December 31, 2017, 2016 and 2015, respectively. Included within these total amortization expense amounts are $330, $386, and $473 related to amortization of favorable and unfavorable leases for the years ended December 31, 2017, 2016 and 2015, respectively. Amortization of favorable and unfavorable leases is recorded within store operations as a component of rent expense in the consolidated statements of operations. The anticipated annual amortization expense to be recognized in future years as of December 31, 2017 is as follows: Amount 2018 $ 14,583 2019 14,215 2020 12,517 2021 12,422 2022 12,419 Thereafter 23,201 Total $ 89,357

Long-term debt

Long-term debt	12 Months Ended
	Dec. 31, 2017
Debt Disclosure [Abstract]
Long-term debt	(7) Long-term debt Long-term debt as of December 31, 2017 and 2016 consists of the following: December 31, 2017 December 31, 2016 Term loan B requires quarterly installments plus interest through the term of the loan, maturing March 31, 2021. Outstanding borrowings bear interest at LIBOR or base rate (as defined) plus a margin at the election of the borrower (4.59% at December 31, 2017 and 4.33% at December 31, 2016) $ 709,470 $ 716,654 Revolving credit line, requires interest only payments through the term of the loan, maturing March 31, 2019. Outstanding borrowings bear interest at LIBOR or base rate (as defined) plus a margin at the election of the borrower (6.25% at December 31, 2017 and 6.0% at December 31, 2016) — — Total debt, excluding deferred financing costs 709,470 716,654 Deferred financing costs, net of accumulated amortization (5,709 ) (7,466 ) Total debt 703,761 709,188 Current portion of long-term debt and line of credit 7,185 7,185 Long-term debt, net of current portion $ 696,576 $ 702,003 On March 31, 2014, the Company entered into a five-year $430,000 credit facility with a consortium of banks and lenders to refinance its existing indebtedness, as well as to provide funds for working capital, capital expenditures, acquisitions, a $173,900 dividend and general corporate purposes. The facility consisted of a $390,000 Term Loan and a $40,000 Revolving Credit Facility. On March 31, 2015, the Company amended this credit facility to increase the Term Loan to $510,000 to fund a cash dividend of $140,000. On November 10, 2016, the Company amended the credit facility to increase the Revolving Credit Facility to $75,000, reduce the interest rate margin for term loan borrowings by 25 basis points, and increase the Term Loan to $718,450 primarily in order to fund a cash dividend and other equivalent payments totaling $271,011. In connection with the amendment, during the year ended December 31, 2016, the Company capitalized and deferred financing costs of $2,219, recorded expense of $3,001 related to certain third party fees included in other expense on the consolidated statement of operations, and a loss on extinguishment of debt of $606 included in interest expense on the consolidated statement of operations. The unused portion of the Revolving Credit Facility as of December 31, 2017 was $75,000. The Term Loan calls for quarterly principal installment payments of $1,796 through March 2021. On May 26, 2017, the Company amended the credit facility to reduce the applicable interest rate margin for term loan borrowings by 50 basis points, to LIBOR plus 300 basis points, with an additional 25 basis point reduction in applicable interest rate possible in the future so long as the Total Net Leverage Ratio (as defined in the credit agreement) is less than 3.50 to 1.00. The amendment to the credit agreement also reduced the interest rate margin for revolving loan borrowings by 25 basis points. In connection with the amendment to the credit agreement, in the year ended December 31, 2017, the Company capitalized deferred financing costs of $257, recorded expense of $1,021 related to certain third party fees included in other expense on the consolidated statement of operations, and a loss on extinguishment of debt of $79 included in interest expense on the consolidated statement of operations. The credit facility requires the Company to meet certain financial covenants, which the Company was in compliance with as of December 31, 2017. The facility is secured by all of the Company’s assets, excluding the assets attributable to the consolidated VIEs (see Note 3). Future annual principal payments of long-term debt as of December 31, 2017 are as follows: Amount 2018 $ 7,185 2019 7,185 2020 7,185 2021 687,915 2022 - Thereafter - Total $ 709,470

Derivative instruments and hedg

Derivative instruments and hedging activities	12 Months Ended
	Dec. 31, 2017
Derivative Instruments And Hedging Activities Disclosure [Abstract]
Derivative instruments and hedging activities	(8) Derivative instruments and hedging activities The Company utilizes interest-rate-related derivative instruments to manage its exposure related to changes in interest rates on its variable-rate debt instruments. The Company does not enter into derivative instruments for any purpose other than cash flow hedging. The Company does not speculate using derivative instruments. By using derivative financial instruments to hedge exposures to changes in interest rates, the Company exposes itself to credit risk and market risk. Credit risk is the failure of the counterparty to perform under the terms of the derivative contract. When the fair value of a derivative contract is an asset, the counterparty owes the Company, which creates credit risk for the Company. When the fair value of a derivative contract is a liability, the Company owes the counterparty and, therefore, the Company is not exposed to the counterparty’s credit risk in those circumstances. The Company minimizes counterparty credit risk in derivative instruments by entering into transactions with high-quality counterparties whose credit rating is higher than A1/A+ at the inception of the derivative transaction. The derivative instruments entered into by the Company do not contain credit-risk-related contingent features. Market risk is the adverse effect on the value of a derivative instrument that results from a change in interest rates. The market risk associated with interest-rate contracts is managed by establishing and monitoring parameters that limit the types and degree of market risk that may be undertaken. The Company assesses interest rate risk by continually identifying and monitoring changes in interest rate exposures that may adversely impact expected future cash flows and by evaluating hedging opportunities. The Company monitors interest rate risk attributable to both the Company’s outstanding or forecasted debt obligations as well as the Company’s offsetting hedge positions. In order to manage the market risk arising from the outstanding term loans, the Company has entered into a series of interest rate caps. During the year ended December 31, 2017, the Company entered into two additional interest rate caps effective March 31, 2017 and terminating on March 31, 2019 with variable notional amounts in order to hedge one month LIBOR greater than 2.5%. As of December 31, 2017, the Company had interest rate cap agreements with notional amounts of $134,000 outstanding that were entered into in order to hedge three month LIBOR greater than 1.5%, and interest rate cap agreements with notional amounts of $221,633 that were entered into in order to hedge one month LIBOR greater than 2.5%. Changes in the fair value of interest rate swaps and caps designated as hedging instruments that effectively offset the variability of cash flows associated with variable-rate, long-term debt obligations are reported in accumulated other comprehensive income. These amounts subsequently are reclassified into interest expense as a yield adjustment of the hedged interest payments in the same period in which the related interest affects earnings. The interest rate cap balances of $340 and $306 were recorded within other assets in the consolidated balance sheets as of December 31, 2017 and 2016, respectively. These amounts have been measured at fair value and are considered to be a Level 2 fair value measurement. The Company recorded an increase to the value of its interest rate caps of $1,143, net of tax of $280, for the year ended December 31, 2017, and reductions to the value of its interest rate caps of $78 net of tax of $35, and $1,388, net of tax of $29, during the years ended December 31, 2016, and 2015, respectively, within other comprehensive income (loss). As of December 31, 2017, the Company expects to reclassify immaterial gains included in accumulated other comprehensive income (loss) into earnings during the next 12 months. Transactions and events expected to occur over the next twelve months that will necessitate reclassifying these derivatives’ gains to earnings include quarterly payments on interest rate caps that are in the money.

Deferred revenue

Deferred revenue	12 Months Ended
	Dec. 31, 2017
Deferred Revenue Disclosure [Abstract]
Deferred revenue	(9) Deferred revenue The summary set forth below represents the balances in deferred revenue as of December 31, 2017 and 2016: December 31, 2017 December 31, 2016 Prepaid membership fees $ 5,198 $ 5,034 Enrollment fees 1,014 1,240 Equipment discount 2,567 2,796 Annual membership fees 8,113 6,775 Area development and franchise fees 10,631 10,286 Total deferred revenue 27,523 26,131 Long-term portion of deferred revenue 8,440 8,351 Current portion of deferred revenue $ 19,083 $ 17,780 Equipment deposits received in advance of delivery, placement and customer acceptance as of December 31, 2017 and 2016 were $6,498 and $2,170, respectively and are expected to be recognized as revenue in the next twelve months. The Company wrote-off $107 and $1,754 of expiring equipment discounts in the years ended December 31, 2017 and 2016, respectively, that were originally recorded in connection with the March 31, 2014 acquisition of eight franchisee-owned stores. These amounts are included as a gain in other expense on the consolidated statement of operations.

Related party transactions

Related party transactions	12 Months Ended
	Dec. 31, 2017
Related Party Transactions [Abstract]
Related party transactions	(10) Related party transactions Amounts due from related parties of $3,020 and $2,864 as of December 31, 2017 and 2016, respectively, primarily relate to currently due or potential reimbursements for certain taxes accrued or paid by the Company (see note 14). Activity with franchisees considered to be related parties is summarized below. For the Year Ended December 31, 2017 2016 2015 Franchise revenue $ 2,130 $ 1,760 $ 1,232 Equipment revenue 3,464 1,338 1,686 Total revenue from related parties $ 5,594 $ 3,098 $ 2,918 Additionally, the Company had deferred ADA revenue from related parties of $389 and $422 as of December 31, 2017 and 2016, respectively. The Company entered into a consulting agreement that continues through December 31, 2018 with a shareholder and former executive officer of the Company. The Company paid rent and lease termination costs for its former headquarters to MMC Fox Run, LLC, which is currently owned by Chris Rondeau, our CEO, and Marc Grondahl, a shareholder and former executive officer and former member of our board of directors, in the amounts of $898, $406, and $412, for the years ended December 31, 2017, 2016 and 2015, respectively. The Company paid management fees to TSG totaling $0, $0, and $1,899 during the years ended December 31, 2017, 2016 and 2015 As of December 31, 2017 and 2016 A member of the Company’s board of directors, who is also a franchisee, holds an approximate 10.5% ownership of a company that sells amenity tracking compliance software to Planet Fitness stores. As of December 31, 2017, the software was being utilized at 15 corporate-owned stores and approximately 300 franchise stores.

Stockholder's equity

Stockholder's equity	12 Months Ended
	Dec. 31, 2016
Equity [Abstract]
Stockholder's equity	(11) Stockholder’s equity The recapitalization transactions The Company refers to the Merger, Reclassification and entry into the Exchange agreement, each as described below, as the “recapitalization transactions.” The Merger was effected pursuant to a merger agreement by and among the Company and Planet Fitness Holdings, L.P. (a predecessor entity to the Company) and the recapitalization transactions were effected pursuant to a recapitalization agreement by and among the Company, Pla-Fit Holdings, the Continuing LLC Owners and Direct TSG Investors. Merger Prior to the Merger, the Direct TSG Investors held interests in Planet Fitness Holdings, L.P., a predecessor entity to the Company that held indirect interests in Pla-Fit Holdings. Planet Fitness Holdings, L.P. was formed in October 2014 and had no material assets, liabilities or operations, other than as a holding company owning indirect interests in Pla-Fit Holdings. The Direct TSG Investors consist of investment funds affiliated with TSG. Pursuant to a merger agreement dated June 22, 2015, upon the pricing of the IPO, Planet Fitness Holdings, L.P. merged with and into the Company, and the interests in Planet Fitness Holdings, L.P. held by the Direct TSG Investors were converted into 26,106,930 shares of Class A common stock of the Company. The Company refers to this as the “Merger.” All shares of Class A common stock have both voting and economic rights in Planet Fitness, Inc. The Merger was effected on August 5, 2015, prior to the time our Class A common stock was registered under the Exchange Act and prior to the completion of the IPO. Reclassification The equity interests of Pla-Fit Holdings previously consisted of three different classes of limited liability company units (Class M, Class T and Class O). Prior to the completion of the IPO, the limited liability company agreement of Pla-Fit Holdings was amended and restated to, among other things, modify its capital structure to create a single new class of units, the Holdings Units. The Company refers to this capital structure modification as the “Reclassification.” The Direct TSG Investors’ indirect interest in Pla-Fit Holdings was held through Planet Fitness Holdings, L.P. As a result, following the Merger, in which Planet Fitness Holdings, L.P. merged with and into the Company, the Direct TSG Investors’ indirect interests in Pla-Fit Holdings are held through the Company. Therefore, the Holdings Units received in the Reclassification were allocated to: (1) the Continuing LLC Owners based on their existing interests in Pla-Fit Holdings; and (2) the Company to the extent of the Direct TSG Investors’ indirect interest in Pla-Fit Holdings. The number of Holdings Units allocated to the Company in the Reclassification was equal to the number of shares of Class A common stock that the Direct TSG Investors received in the Merger (on a one-for-one basis). The Reclassification was effected on August 5, 2015, prior to the time our Class A common stock was registered under the Exchange Act and prior to the completion of the IPO. Following the Merger and the Reclassification, the Company issued to Continuing LLC Owners 72,602,810 shares of Class B common stock, one share of Class B common stock for each Holdings Unit they held. The shares of Class B common stock have no rights to dividends or distributions, whether in cash or stock, but entitle the holder to one vote per share on matters presented to stockholders of the Company. The Continuing LLC Owners consist of investment funds affiliated with TSG and certain employees and directors. Pursuant to the LLC agreement that went into effect at the time of the Reclassification (“New LLC Agreement”), the Company was designated as the sole managing member of Pla-Fit Holdings. Accordingly, the Company has the right to determine when distributions will be made by Pla-Fit Holdings to its members and the amount of any such distributions (subject to the requirements with respect to the tax distributions described below). If the Company authorizes a distribution by Pla-Fit Holdings, the distribution will be made to the members of Pla-Fit Holdings, including the Company, pro rata in accordance with the percentages of their respective Holdings Units. The holders of Holdings Units will incur U.S. federal, state and local income taxes on their allocable share of any taxable income of Pla-Fit Holdings (as calculated pursuant to the New LLC Agreement). Net profits and net losses of Pla-Fit Holdings will generally be allocated to its members pursuant to the New LLC Agreement pro rata in accordance with the percentages of their respective Holdings Units. The New LLC Agreement provides for cash distributions to the holders of Holdings Units for purposes of funding their tax obligations in respect of the income of Pla-Fit Holdings that is allocated to them, to the extent other distributions from Pla-Fit Holdings for the relevant year have been insufficient to cover such liability. Generally, these tax distributions are computed based on the estimated taxable income of Pla-Fit Holdings allocable to the holders of Holdings Units multiplied by an assumed, combined tax rate equal to the maximum rate applicable to an individual or corporation resident in Hampton, NH (taking into account the non-deductibility of certain expenses and the character of the Company’s income). Exchange agreement Following the Merger and the Reclassification, the Company and the Continuing LLC Owners entered into an exchange agreement under which the Continuing LLC Owners (or certain permitted transferees thereof) have the right, from time to time and subject to the terms of the exchange agreement, to exchange their Holdings Units, along with a corresponding number of shares of Class B common stock, for shares of Class A common stock (or cash at the option of the Company) on a one-for-one basis, subject to customary conversion rate adjustments for stock splits, stock dividends, reclassifications and similar transactions. As a Continuing LLC Owner exchanges Holdings Units, along with a corresponding number of shares of Class B common stock, for shares of Class A common stock, the number of Holdings Units held by the Company will increase by a corresponding amount as it acquires the exchanged Holdings Units and cancels a corresponding number of shares of Class B common stock. IPO transactions In connection with the completion of the IPO on August 11, 2015, in order to facilitate the disposition of equity interests in Pla-Fit Holdings held by Continuing LLC Owners affiliated with TSG, the Company used the net proceeds received to purchase issued and outstanding Holdings Units from these Continuing LLC Owners that they received in the Reclassification. In connection with the IPO, the Company purchased 10,491,055 issued and outstanding Holdings Units from these Continuing LLC Owners for an aggregate of $156,946. This is in addition to the 26,106,930 Holdings Units that the Company acquired in the Reclassification on a one-for-one basis in relation to the number of shares of Class A common stock issued to the Direct TSG Investors in the Merger. Accordingly, following the IPO, the Company held 36,597,985 Holdings Units, which is equal to the number of shares of Class A common stock that were issued to the Direct TSG Investors and investors in the IPO. The Direct TSG Investors, who did not receive Holdings Units in the Reclassification but received shares of Class A common stock in the Merger, sold 5,033,945 shares of Class A common stock in the IPO as selling stockholders. All expenses of the IPO, other than underwriter discounts and commissions, were borne by Pla-Fit Holdings or reimbursed by Pla-Fit Holdings to the Company and amounted to $7,697 for the year ended December 31, 2015. These amounts were recorded in selling, general, and administrative expense in the accompanying statements of operations and could not be capitalized and offset against the proceeds from the offering because the Company did not retain any of the proceeds from the IPO. June 2016 Secondary Offering As described in Note 1, on June 28, 2016 the Company completed the June Secondary Offering of 11,500,000 shares of our Class A common stock at a price of $16.50 per share. All of the shares sold in the offering were offered by Direct TSG Investors and the participating Continuing LLC Owners. The Company did not receive any proceeds from the sale of shares of Class A common stock offered by the Direct TSG Investors and the participating Continuing LLC Owners. The shares sold in the offering consisted of (i) 3,608,840 existing shares of Class A common stock held by the Direct TSG Investors and (ii) 7,891,160 newly-issued shares of Class A common stock issued in connection with the exercise of the exchange right by the Continuing LLC Owners that participated in the June Secondary Offering. Simultaneously, and in connection with the exchange, 7,891,160 shares of Class B common stock were surrendered by the Continuing LLC Owners that participated in the June Secondary Offering and canceled. Additionally, in connection with the exchange, Planet Fitness, Inc. received 7,891,160 Holdings Units, increasing its total ownership interest in Pla-Fit Holdings. September 2016 Secondary Offering As described in Note 1, on September 28, 2016, the Company completed the September Secondary Offering of 8,000,000 shares of our Class A common stock at a price of 19.62 per share. All of the shares sold in the offering were offered by the Direct TSG Investors and participating Continuing LLC Owners. The Company did not receive any proceeds from the sale of shares of Class A common stock offered by the Direct TSG Investors and the participating Continuing LLC Owners. The shares sold in the offering consisted of (i) 2,593,981 existing shares of Class A common stock held by the Direct TSG Investors and (ii) 5,406,019 newly-issued shares of Class A common stock issued in connection with the exercise of the exchange right by the Continuing LLC Owners that participated in the September Secondary Offering. Simultaneously, and in connection with the exchange, 5,406,019 shares of Class B common stock were surrendered by the Continuing LLC Owners that participated in the September Secondary Offering and canceled. Additionally, in connection with the exchange, Planet Fitness, Inc. received 5,406,019 Holdings Units, increasing its total ownership interest in Pla-Fit Holdings. November 2016 Secondary Offering As described in Note 1, on November 22, 2016, the Company completed the November Secondary Offering of 15,000,000 shares of our Class A common stock at a price of $23.22 per share. All of the shares sold in the offering were offered by the Direct TSG Investors and participating Continuing LLC Owners. The Company did not receive any proceeds from the sale of shares of Class A common stock offered by the Direct TSG Investors and the participating Continuing LLC Owners. The shares sold in the offering consisted of (i) 4,863,715 existing shares of Class A common stock held by the Direct TSG Investors and (ii) 10,136,285 newly-issued shares of Class A common stock issued in connection with the exercise of the exchange right by the Continuing LLC Owners that participated in the November Secondary Offering. Simultaneously, and in connection with the exchange, 10,136,285 shares of Class B common stock were surrendered by the Continuing LLC Owners that participated in the November Secondary Offering and canceled. Additionally, in connection with the exchange, Planet Fitness, Inc. received 10,136,285 Holdings Units, increasing its total ownership interest in Pla-Fit Holdings. March 2017 Secondary Offering As described in Note 1, on March 14, 2017, the Company completed the March Secondary Offering of 15,000,000 shares of its Class A common stock at a price of $20.44 per share. All of the shares sold in the March Secondary Offering were offered by certain existing holders of Holdings Units and the Direct TSG Investors. The Company did not receive any proceeds from the sale of shares of Class A common stock offered by the Direct TSG Investors and the participating holders of Holdings Units. The shares sold in the March Secondary Offering consisted of (i) 4,790,758 existing shares of Class A common stock held by the Direct TSG Investors and (ii) 10,209,242 newly-issued shares of Class A common stock issued in connection with the exercise of the exchange right by the holders of Holdings Units that participated in the March Secondary Offering. Simultaneously, and in connection with the exchange, 10,209,242 shares of Class B common stock were surrendered by the holders of Holdings Units that participated in the March Secondary Offering and canceled. Additionally, in connection with the exchange, Planet Fitness, Inc. received 10,209,242 Holdings Units, increasing its total ownership interest in Pla-Fit Holdings. May 2017 Secondary Offering As described in Note 1, on May 10, 2017, the Company completed the May Secondary Offering of 16,085,510 shares of its Class A common stock at a price of $20.28 per share. All of the shares sold in the May Secondary Offering were offered by certain existing holders of Holdings Units and the Direct TSG Investors. The Company did not receive any proceeds from the sale of shares of Class A common stock offered by the Direct TSG Investors and the participating holders of Holdings Units. The shares sold in the May Secondary Offering consisted of (i) 5,215,691 existing shares of Class A common stock held by the Direct TSG Investors and (ii) 10,869,819 newly-issued shares of Class A common stock issued in connection with the exercise of the exchange right by the holders of Holdings Units that participated in the May Secondary Offering. Simultaneously, and in connection with the exchange, 10,869,819 shares of Class B common stock were surrendered by the holders of Holdings Units that participated in the May Secondary Offering and canceled. Additionally, in connection with the exchange, Planet Fitness, Inc. received 10,869,819 Holdings Units, increasing its total ownership interest in Pla-Fit Holdings. Other Exchanges In addition to the secondary offerings mentioned above, during the year ended December 31, 2017 and 2016, respectively, certain Continuing LLC Owners have exercised their exchange right and exchanged 4,762,943 and 1,271,146 Holdings Units for 4,762,943 1,271,146 newly-issued shares of Class A common stock. Simultaneously, and in connection with these exchanges, 4,762,943 and 1,271,146 shares of Class B common stock were surrendered by the Continuing LLC Owners that exercised their exchange right and cancelled in the years ended December 31, 2017 and 2016, respectively. Additionally, in connection with these exchanges, Planet Fitness, Inc. received 4,762,943 and 1,271,146 Holdings Units, during the years ended December 31, 2017 and 2016, respectively, increasing its total ownership in Pla-Fit Holdings. Future exchanges of Holdings Units by the Continuing LLC Owners will result in a change in ownership and reduce the amount recorded as non-controlling interest and increase additional paid-in capital on our consolidated balance sheets. As a result of the recapitalization transactions, the IPO, completion of our secondary offerings, and other exchanges and equity activity, as of December 31, 2017: • the investors in the IPO, the Company’s secondary offerings, other exchanges and equity activity collectively owned 87,188,160 shares of our Class A common stock, representing 88.6% of the voting power in the Company and, through the Company, 88.6% of the economic interest in Pla-Fit Holdings; • the Continuing LLC Owners collectively hold 11,192,740 Holdings Units, representing 11.4% of the economic interest in Pla-Fit Holdings and 11,192,740 shares of our Class B common stock, representing 11.4% of the voting power in the Company; and • the Direct TSG Investors own zero shares of our Class A common stock, representing 0% of the voting power in the Company and, through the Company, 0% of the economic interest in Pla-Fit Holdings. Dividends The Company did not declare or pay any dividends during the year ended December 31, 2017. Dividends declared and paid to holders of the Company’s Class A common stock during the year ended December 31, 2016 were $169,282, or $2.78 per share of Class A common stock. The dividend was declared on November 10, 2016 and paid on December 5, 2016 to Class A common stock holders of record as of November 22, 2016. The Company also paid cash dividend equivalents of $101,729, or $2.78 per share, to holders of Holdings Units on December 5, 2016 and accrued $3,899 of dividend equivalents for future payment to holders of unvested share awards to be paid upon vesting of the related awards.

Equity-based Compensation

Equity-based Compensation	12 Months Ended
	Dec. 31, 2017
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]
Equity-based Compensation	(12) Equity-based compensation 2013 Equity Incentive Plan In 2013, the Company’s Board of Directors adopted the 2013 Equity Incentive Plan (the “2013 Plan”). Under the 2013 Plan, the Company granted awards in the form of Class M Units to certain employees and directors of the Company and its subsidiaries. The Class M Units received distributions (other than tax distributions) only upon a liquidity event, as defined, that exceeded a threshold equivalent to the fair value of the Company, as determined by the Company’s Board of Directors, at the grant date. Eighty percent of the awards vest over five years of continuous employment or service while the other twenty percent only vest in the event of an initial public offering of the Company’s common stock or that of its parent or one of its subsidiaries, subject to the holder of the Class M Units remaining employed or providing services on the date of such initial public offering. All awards include a repurchase option at the election of the Company for the vested portion upon termination of employment or service, and have a ten year contractual term. These awards are accounted for as equity at their fair value as of the grant date. In connection with the IPO and related recapitalization transactions as described in Note 1, all of the outstanding Class M Units were converted into Holdings Units and Class B common shares of Planet Fitness, Inc. in accordance with the terms of the awards. The Company’s IPO constituted a qualifying event under the terms of the awards and as a result 4,238,338 Holdings Units and corresponding Class B Common shares were issued to the existing Class M Unit holders with a weighted-average grant date fair value of $1.52 per share. The Company recorded $152 and $784 of compensation expense in the years ended December 31, 2017 and 2016, respectively, related to these awards. The fair value of each award was estimated on the date of grant using a Monte Carlo simulation model. During the year ended December 31, 2016, the Company modified the vesting terms of 22,527 outstanding Holdings Units such that those units were fully vested immediately. In connection with the modification, the Company recorded $337 of compensation expense in the year ended December 31, 2016. During the year ended December 31, 2015, the Company modified the vesting terms of 10.737 outstanding Class M Units such that those units were fully vested and eligible to receive distributions following a liquidity event. A summary of unvested Holdings Unit activity is presented below: Holdings Units Weighted average grant date fair value Weighted average remaining contractual term (years) Aggregate intrinsic value Unvested outstanding at January 1, 2017 1,025,016 $ 1.52 Units granted — — Units forfeited (150,181 ) $ 1.52 Units vested (604,614 ) $ 1.52 Unvested outstanding at December 31, 2017 270,221 $ 1.52 0.7 $ 9,358 The amount of total unrecognized compensation cost related to all awards under this plan was $53 as of December 31, 2017, which is expected to be recognized over a weighted-average period of 0.7 years. 2015 Omnibus Incentive Plan Stock Options In August 2015, the Company adopted the 2015 Omnibus Incentive Plan (the "2015 Plan") under which the Company may grant options and other equity-based awards to purchase up to 7,896,800 shares to employees, directors and officers. All stock options awarded vest annually, on a tranche by tranche basis, over a period of four years with a maximum contractual term of 10 years. The fair value of stock option awards granted were determined on the grant date using the Black-Scholes valuation model based on the following assumptions: Year ended December 31, 2017 2016 Expected term (years) (1) 6.25 6.25 Expected volatility (2) 28.6% - 32.9% 33.2% - 34.4% Risk-free interest rate (3) 1.86% - 2.10% 1.31% - 1.76% Dividend yield (4) — — (1) Expected term represents the estimated period of time until an award is exercised and was determined using the simplified method. (2) Expected volatility is based on the historical volatility of a selected peer group over a period equivalent to the expected term. (3) The risk-free rate is an interpolation of yields on U.S. Treasury securities with maturities equivalent to the expected term. (4) Based on an assumed a dividend yield of zero at the time of grant. A summary of stock option activity for the year ended December 31, 2017: Stock Options Weighted exercise price Weighted average remaining contractual term (years) Aggregate intrinsic value Outstanding at January 1, 2017 404,470 $ 17.49 Granted 617,904 $ 20.97 Exercised (27,191 ) $ 17.63 Forfeited (76,977 ) $ 20.32 Outstanding at December 31, 2017 918,206 $ 19.59 8.7 $ 13,811 Vested or expected to vest at December 31, 2017 918,206 $ 19.59 8.7 $ 13,811 Exercisable at December 31, 2017 90,046 $ 17.23 8.2 $ 1,567 The weighted-average grant date fair value of stock options granted during the year ended December 31, 2017 was $7.73. During the years ended December 31, 2017 and 2016, $2,195 and $846, respectively, was recorded to selling, general and administrative expense related to these stock options. As of December 31, 2017, total unrecognized compensation expense related to unvested stock options, was $3,666, which is expected to be recognized over a weighted-average period of 1.9 years. Restricted stock units During the year ended December 31, 2017, the Company granted 13,498 restricted Class A stock units (“RSUs”) to members of its Board of Directors under the 2015 Plan. The RSUs granted vest on the first anniversary of the grant date, provided that the recipient continues to serve on the Board of Directors through the vesting dates. RSU awards are valued using the intrinsic value method. Stock Options Weighted fair value Weighted average remaining contractual term (years) Aggregate intrinsic value Unvested outstanding at January 1, 2017 7,887 $ 19.02 Granted 13,498 $ 24.25 Vested (5,167 ) $ 19.35 Unvested outstanding at December 31, 2017 16,218 $ 23.26 0.6 $ 462 The weighted-average grant date fair value of RSUs granted during the year ended December 31, 2017 was $24.25. During the years ended December 31, 2017 and 2016, $184 and $98, respectively, was recorded to selling, general and administrative expense related to these RSUs. As of December 31, 2017, total unrecognized compensation expense related to unvested RSUs was $219, which is expected to be recognized over a weighted-average period of 0.6 years.

Earnings per share

Earnings per share	12 Months Ended
	Dec. 31, 2017
Earnings Per Share [Abstract]
Earnings per share	(13) Earnings per share Basic earnings per share of Class A common stock is computed by dividing net income attributable to Planet Fitness, Inc. for the years ended December 31, 2017 and 2016, and the period from August 6, 2015 through December 31, 2015, the periods following the recapitalization transactions and IPO, by the weighted-average number of shares of Class A common stock outstanding during the same periods. Diluted earnings per share of Class A common stock is computed by dividing net income attributable to Planet Fitness, Inc. by the weighted-average number of shares of Class A common stock outstanding adjusted to give effect to potentially dilutive securities. There were no shares of Class A or Class B common stock outstanding prior to August 6, 2015, therefore no earnings per share information has been presented for any period prior to that date. Shares of the Company’s Class B common stock do not share in the earnings or losses attributable to Planet Fitness, Inc. and are therefore not participating securities. As such, separate presentation of basic and diluted earnings per share of Class B common stock under the two-class method has not been presented. Shares of the Company’s Class B common stock are, however, considered potentially dilutive shares of Class A common stock because shares of Class B common stock, together with the related Holdings Units, are exchangeable into shares of Class A common stock on a one-for-one basis. The following table sets forth reconciliations of the numerators and denominators used to compute basic and diluted earnings per share of Class A common stock: Basic net income per share: Year ended December 31, 2017 Year ended December 31, 2016 August 6, 2015 through December 31, 2015 Numerator Net income $ 55,601 $ 71,247 $ 23,454 Less: net income attributable to non-controlling interests 22,455 49,747 19,348 Net income attributable to Planet Fitness, Inc. - basic & diluted $ 33,146 $ 21,500 $ 4,106 Denominator Weighted-average shares of Class A common stock outstanding - basic 78,910,390 43,300,288 36,243,557 Effect of dilutive securities: Stock options 56,198 1,489 — Restricted stock units 4,962 2,908 — Weighted-average shares of Class A common stock outstanding - diluted 78,971,550 43,304,685 36,243,557 Earnings per share of Class A common stock - basic $ 0.42 $ 0.50 $ 0.11 Earnings per share of Class A common stock - diluted $ 0.42 $ 0.50 $ 0.11 Weighted average shares of Class B common stock of 19,483,737, 55,305,992 and 62,466,183 for the years ended December 31, 2017 and 2016, and the period from August 6, 2015 through December 31, 2015, respectively, were evaluated under the if-converted method for potential dilutive effects and were determined to be anti-dilutive. Weighted-average stock options outstanding of 489,133, 208,452 and 108,270 for the years ended December 31, 2017 and 2016, and the period from August 6, 2015 through December 31, 2015, respectively, were evaluated under the treasury stock method for potential dilutive effects and were determined to be anti-dilutive. Weighted average restricted stock units outstanding of 1,829 and 8,160 for the year ended December 31, 2017 and the period from August 6, 2015 through December 31, 2015, respectively, were evaluated under the treasury stock method for potential dilutive effects and were determined to be anti-dilutive.

Income taxes

Income taxes	12 Months Ended
	Dec. 31, 2017
Income Tax Disclosure [Abstract]
Income taxes	(14) Income taxes Income before the provision for income taxes as shown in the accompanying consolidated statements of operations is as follows: Year Ended December 31, 2017 2016 2015 Domestic $ 426,873 $ 88,016 $ 48,716 Foreign 2,308 1,892 (1,438 ) Total income before the provision for income taxes 429,181 89,908 47,278 The provision (benefit) for income taxes consists of the following: Year Ended December 31, 2017 2016 2015 Current: Federal $ (2,600 ) $ 1,206 $ 686 State 2,941 1,428 2,188 Foreign 817 421 139 Total current tax expense 1,158 3,055 3,013 Deferred: Federal 365,470 11,633 5,636 State 6,857 3,755 935 Foreign 95 218 (436 ) Total deferred tax expense 372,422 15,606 6,135 Provision for income taxes $ 373,580 $ 18,661 $ 9,148 As a result of the recapitalization transactions, the Company became the sole managing member of Pla-Fit Holdings, which is treated as a partnership for U.S. federal and most applicable state and local income tax purposes. As a partnership, Pla-Fit Holdings is not subject to U.S. federal and certain state and local income taxes. Any taxable income or loss generated by Pla-Fit Holdings is passed through to and included in the taxable income or loss of its members, including the Company following the recapitalization transactions, on a pro rata basis. Planet Fitness, Inc. is subject to U.S. federal income taxes, in addition to state and local income taxes with respect to our allocable share of any taxable income of Pla-Fit Holdings following the recapitalization transactions. The Company is also subject to taxes in foreign jurisdictions. On December 22, 2017, the 2017 Tax Act was enacted, making significant changes to the Internal Revenue Code. Changes include, but are not limited to, a corporate tax rate decrease from 35% to 21% beginning on January 1, 2018, the transition of U.S international taxation from a worldwide tax system to a modified territorial system, and a one-time transition tax on the mandatory deemed repatriation of cumulative foreign earnings as of December 31, 2017. We have calculated our best estimate of the impact of the 2017 Tax Act in our year end income tax provision in accordance with our understanding of the law and available guidance and as a result have recorded $334,619 as additional income tax expense in the fourth quarter of 2017, the period in which the legislation was enacted, of which $334,022 related to the remeasurement of certain deferred tax assets and liabilities, and $597 related to mandatory repatriation. The 2017 Tax Act also caused a remeasurement of our tax benefit arrangements, as discussed in more detail below. On December 22, 2017, Staff Accounting Bulletin No. 118 ("SAB 118") was issued to address the application of U.S. GAAP in situations when a registrant does not have the necessary information available, prepared, or analyzed (including computations) in reasonable detail to complete the accounting for certain income tax effects of the 2017 Tax Act. The Company has analyzed the 2017 Tax Act and made reasonable estimates of the effects on our consolidated financial statements and tax disclosures, including changes to our existing deferred tax balances, the mandatory repatriation tax and remeasurement of our tax benefit arrangements. The Company will continue to analyze the effects of the 2017 Tax Act on its consolidated financial statements. Any additional impacts from the enactment of the Tax Act will be recorded as they are identified during the measurement period and we may record additional provisional amounts or adjustments to provisional amounts during 2018. A reconciliation of the U.S. statutory income tax rate to the Company’s effective tax rate is as follows: Year Ended December 31, 2017 2016 2015 U.S. statutory tax rate 35.0 % 35.0 % 35.0 % State and local taxes, net of federal benefit 1.0 % 4.9 % 6.2 % State rate change impact on deferred taxes 0.8 % (1.4 )% 6.9 % Federal rate change impact on deferred taxes 77.8 % — % — % Tax benefit arrangement liability adjustment (25.8 )% — % (2.1 )% Foreign tax rate differential — % (0.3 )% 0.3 % Withholding taxes and other 0.1 % — % 0.2 % Reserve for uncertain tax position 0.1 % 3.1 % — % Income attributable to non-controlling interests (1.9 )% (20.5 )% (27.1 )% Effective tax rate 87.1 % 20.8 % 19.4 % The Company incurs U.S. federal and state income taxes on its pro rata share of income flowed through from Pla-Fit Holdings. Our current tax rate on such income was approximately 39.5%, 39.5%, and 39.4% for the years ended December 31, 2017, 2016 and 2015, respectively. The provision for income taxes also reflects a state tax rate of 2.1%, 2.0% and 2.5% for the years ended December 31, 2017, 2016 and 2015, respectively, applied to non-controlling interests, representing the remaining percentage of income before taxes, excluding income from variable interest entities, related to Pla-Fit Holdings. As of December 31, 2017, the Company recorded U.S. tax on mandatory repatriation of the undistributed earnings of foreign operations as well as foreign withholding tax. Undistributed earnings of foreign operations were not material for the year ended December 31, 2016. Deferred income taxes are provided for the effects of temporary differences between the tax basis of an asset or liability and its reported amount in the accompanying consolidated balance sheets. These temporary differences result in taxable or deductible amounts in future years. Details of the Company’s deferred tax assets and liabilities are summarized as follows: Year Ended December 31, 2017 2016 Deferred tax assets: Accrued expense and reserves $ 1,422 $ 865 Deferred revenue 1,900 2,029 Goodwill and intangible assets 404,547 406,447 Net operating loss 603 22 Other 3,619 4,218 Deferred tax assets $ 412,091 $ 413,581 Deferred tax liabilities: Prepaid expenses (773 ) (781 ) Property and equipment (5,165 ) (3,631 ) Total deferred tax liabilities $ (5,938 ) $ (4,412 ) Total deferred tax assets and liabilities $ 406,153 $ 409,169 Reported as: Deferred income taxes - non-current assets $ 407,782 $ 410,407 Deferred income taxes - non-current liabilities (1,629 ) (1,238 ) Total deferred tax assets and liabilities $ 406,153 $ 409,169 The Company has net operating loss carryforwards related to its U.S. operations of approximately $2,725, which begin to expire in 2037. The Company believes as of December 31, 2017 it is more likely than not that the results of future operations will generate sufficient taxable income to realize all deferred tax assets, and as such no value allowance has been recorded. A summary of the changes in the Company’s unrecognized tax positions is as follows: Year Ended December 31, 2017 2016 Balance at beginning of year $ 2,608 $ 300 Increases related to prior year tax positions — 2,308 Balance at end of year $ 2,608 $ 2,608 During the year ended December 31, 2017, the Company recognized $152 within current tax expense related to the interest on a reserve for an uncertain tax position. The uncertain tax position relates to a potential liability associated with a 2012 state filing position currently under audit by the taxing authorities. While the Company believes it is more likely than not that its position will be sustained, the amount recorded after assessing the likelihood of various potential outcomes is based upon the facts and circumstances known as of December 31, 2017. In connection with the 2012 Acquisition of Pla-Fit Holdings on November 8, 2012 by TSG, the sellers are obligated to indemnify the Company for certain pre-acquisition tax liabilities. The Company has therefore recorded an asset and corresponding other income of $152 in connection with the indemnification in the year ended December 31, 2017. The Company recognizes interest and penalties, if applicable, related to uncertain tax positions as a component of income tax expense. Interest and penalties recorded for the years ended December 31, 2017 and 2016 were $152 and $465, respectively. Interest and penalties for the year ended December 31, 2015 were not material. As of December 31, 2017 and 2016, the total liability related to uncertain tax positions was $2,608, excluding interest. The amount of unrecognized tax benefits as of December 31, 2017 that, if recognized, would reduce income tax expense is $2,608. As of December 31, 2017, the Company anticipates that the liability for unrecognized tax benefits could decrease by up to $2,608 within the next twelve months due to the expiration of certain statutes of limitation or the settlement of examinations or issues with tax authorities The Company and its subsidiaries file U.S. federal income tax returns, as well as tax returns in various state and foreign jurisdictions. Generally, the tax years 2014 through 2017 remain open to examination by the tax authorities in these jurisdictions. The Company is currently under audit in its primary state jurisdiction, New Hampshire, for 2012 and 2013. Tax benefit arrangements The Company’s acquisition of Holdings Units in connection with the IPO and future and certain past exchanges of Holdings Units for shares of the Company’s Class A common stock (or cash at the option of the Company) are expected to produce and have produced favorable tax attributes. In connection with the IPO, the Company entered into two tax receivable agreements. Under the first of those agreements, the Company generally is required to pay to the TRA Holders 85% of the applicable tax savings, if any, in U.S. federal and state income tax that the Company is deemed to realize as a result of certain tax attributes of their Holdings Units sold to the Company (or exchanged in a taxable sale) and that are created as a result of (i) the sales of their Holdings Units for shares of Class A common stock and (ii) tax benefits attributable to payments made under the tax receivable agreement (including imputed interest). Under the second tax receivable agreement, the Company generally is required to pay to the Direct TSG Investors 85% of the amount of tax savings, if any, that the Company is deemed to realize as a result of the tax attributes of the Holdings Units held in respect of the Direct TSG Investors’ interest in the Company, which resulted from the Direct TSG Investors’ purchase of interests in Pla-Fit Holdings in 2012, and certain other tax benefits. Under both agreements, the Company generally retains the benefit of the remaining 15% of the applicable tax savings. Also, pursuant to the exchange agreement (see Note 11), to the extent an exchange results in Pla-Fit Holdings, LLC incurring a current tax liability relating to the New Hampshire business profits tax, the TRA Holders have agreed that they will contribute to Pla-Fit Holdings, LLC an amount sufficient to pay such liability (up to 3.5% of the value receive upon exchange). If and when the Company subsequently realizes a related tax benefit, Pla-Fit Holdings, LLC will distribute the amount of any such tax benefit to the relevant TRA LLC Owner in respect of its contribution. Due to changes in New Hampshire tax law during 2016, the Company no longer expects to incur any such liability under the New Hampshire business profits tax. The Company recorded other income of $317,353, other expense of $72 and other income of $2,549 in the years ended December 31, 2017, 2016 and 2015, respectively, reflecting a change in the tax benefit obligation attributable to a change in the expected tax benefits. Included in this amount i n 2017, was a gain of $316,813 related to the remeasurement of our tax benefit arrangements in connection with changes in the tax rate due to the 2017 Tax Act. In connection with the exchanges that occurred in the secondary offerings and other exchanges during 2017 and 2016, 25,842,004 and 24,704,610 Holdings Units, respectively, were redeemed by the Continuing LLC Owners for newly-issued shares of Class A common stock, resulting in an increase in the tax basis of the net assets of Pla-Fit Holdings subject to the provisions of the tax receivable agreements. As a result of the change in Planet Fitness, Inc.’s ownership percentage of Pla-Fit Holdings that occurred in conjunction with the exchanges, we recorded a decrease to our net deferred tax assets of $24,371 and $25,046, during the years ended December 31, 2017 and 2016, respectively. As a result of these exchanges, during the years ended December 31, 2017 and 2016 we also recognized deferred tax assets in the amount of $394,108 and $332,471, respectively, and corresponding tax benefit arrangement liabilities of $341,089 and $285,730, respectively, representing 85% of the tax benefits due to the TRA Holders. The offset to the entries recorded in connection with exchanges in each year was to stockholders’ equity. The tax benefit obligation was $431,360 and $419,071 as of December 31, 2017 and 2016, respectively. Projected future payments under the tax benefit arrangements are as follows: Amount 2018 $ 31,062 2019 23,298 2020 23,596 2021 24,010 2022 24,482 Thereafter 304,912 Total $ 431,360

Commitments and contingencies

Commitments and contingencies	12 Months Ended
	Dec. 31, 2017
Commitments And Contingencies Disclosure [Abstract]
Commitments and contingencies	(15) Commitments and contingencies (a) Operating lease commitments The Company rents equipment, office, and warehouse space at various locations in the United States and Canada under noncancelable operating leases. Rental expense was $20,296, $19,203, and $18,186 for the years ended December 31, 2017, 2016 and 2015, respectively. Approximate annual future commitments under noncancelable operating leases as of December 31, 2017 are as follows: Amount 2018 $ 14,563 2019 13,439 2020 12,495 2021 10,747 2022 9,993 Thereafter 48,712 Total $ 109,949 (b) Legal matters From time to time, and in the ordinary course of business, the Company is subject to various claims, charges, and litigation, such as employment-related claims and slip and fall cases. The Company is not currently aware of any legal proceedings or claims that the Company believes will have, individually or in the aggregate, a material adverse effect on the Company’s financial position or result of operations. (c) Purchase commitments As of December 31, 2017, the Company had advertising purchase commitments of approximately $30,400, including commitments made by the NAF. In addition, the Company had open purchase orders of approximately $10,823 primarily related to equipment to be sold to franchisees. (d) Guarantees The Company has guaranteed certain leases and debt agreements of entities that were previously related through common ownership. These guarantees relate to leases for operating space, equipment, and other operating costs of franchises operated by the related entities. The Company’s maximum obligation, as a result of its guarantees of leases and debt, is approximately $979 and $1,350 as of December 31, 2017 and 2016, respectively, and would only require payment upon default by the primary obligor. The Company has determined the fair value of these guarantees at inception is not material, and as of December 31, 2017 and 2016, no accrual has been recorded for the Company’s potential obligation under its guaranty arrangement.

Retirement Plan

Retirement Plan	12 Months Ended
	Dec. 31, 2017
Compensation And Retirement Disclosure [Abstract]
Retirement Plan	(16) Retirement Plan The Company maintains a 401(k) deferred tax savings plan (the Plan) for eligible employees. The Plan provides for the Company to make an employer matching contribution currently equal to 100% of employee deferrals up to a maximum of 4% of each eligible participating employees’ wages. Total employer matching contributions expensed in the consolidated statements of operations were approximately $623, $484, and $384 for the years ended December 31, 2017, 2016 and 2015, respectively.

Segments

Segments	12 Months Ended
	Dec. 31, 2017
Segment Reporting [Abstract]
Segments	(17) Segments The Company has three reportable segments: (i) Franchise; (ii) Corporate-owned stores; and (iii) Equipment. The Company’s operations are organized and managed by type of products and services and segment information is reported accordingly. The Company’s chief operating decision maker (the “CODM”) is its Chief Executive Officer. The CODM reviews financial performance and allocates resources by reportable segment. There have been no operating segments aggregated to arrive at the Company’s reportable segments. The Franchise segment includes operations related to the Company’s franchising business in the United States, Puerto Rico, Canada, the Dominican Republic and Panama. The Corporate-owned stores segment includes operations with respect to all Corporate-owned stores throughout the United States and Canada. The Equipment segment includes the sale of equipment to franchisee-owned stores. The accounting policies of the reportable segments are the same as those described in Note 2. The Company evaluates the performance of its segments and allocates resources to them based on revenue and earnings before interest, taxes, depreciation, and amortization, referred to as Segment EBITDA. Revenues for all operating segments include only transactions with unaffiliated customers and include no intersegment revenues. The tables below summarize the financial information for the Company’s reportable segments for the years ended December 31, 2017, 2016 and 2015. The “Corporate and other” column, as it relates to Segment EBITDA, primarily includes corporate overhead costs, such as payroll and related benefit costs and professional services which are not directly attributable to any individual segment. Year Ended December 31, 2017 2016 2015 Revenue Franchise segment revenue - U.S. $ 147,787 $ 114,717 $ 87,299 Franchise segment revenue - International 2,368 1,771 786 Franchise segment total 150,155 116,488 88,085 Corporate-owned stores segment - U.S. 107,712 100,541 95,459 Corporate-owned stores segment - International 4,402 4,180 2,931 Corporate-owned stores segment total 112,114 104,721 98,390 Equipment segment - U.S. 167,673 157,032 144,062 Equipment segment total 167,673 157,032 144,062 Total revenue $ 429,942 $ 378,241 $ 330,537 Franchise segment revenue includes franchise revenue and commission income. Franchise revenue includes revenue generated from placement services of $11,371, $10,513, and $9,806 for the years ended December 31, 2017, 2016 and 2015, respectively. Year Ended December 31, 2017 2016 2015 Segment EBITDA Franchise $ 126,459 $ 97,256 $ 66,030 Corporate-owned stores 46,855 40,847 36,070 Equipment 38,539 36,439 31,936 Corporate and other 284,372 (26,007 ) (30,051 ) Total Segment EBITDA $ 496,225 $ 148,535 $ 103,985 The following table reconciles total Segment EBITDA to income before taxes: Year Ended December 31, 2017 2016 2015 Total Segment EBITDA $ 496,225 $ 148,535 $ 103,985 Less: Depreciation and amortization 31,761 31,502 32,158 Other expense 316,928 1,371 (275 ) Income from operations 147,536 115,662 72,102 Interest expense, net (35,283 ) (27,125 ) (24,549 ) Other income (expense) 316,928 1,371 (275 ) Income before income taxes $ 429,181 $ 89,908 $ 47,278 The following table summarizes the Company’s assets by reportable segment: December 31, 2017 December 31, 2016 Franchise $ 243,348 $ 202,580 Corporate-owned stores 167,367 153,761 Equipment 206,632 208,809 Unallocated 475,118 436,292 Total consolidated assets $ 1,092,465 $ 1,001,442 The table above includes $2,558 and $2,795 of long-lived assets located in the Company’s international corporate-owned stores as of December 31, 2017 and 2016 The following table summarizes the Company’s goodwill by reportable segment: December 31, 2017 December 31, 2016 Franchise $ 16,938 $ 16,938 Corporate-owned stores 67,377 67,377 Equipment 92,666 92,666 Total consolidated goodwill $ 176,981 $ 176,981

Corporate-owned and franchisee-

Corporate-owned and franchisee-owned stores	12 Months Ended
	Dec. 31, 2017
Other Industries [Abstract]
Corporate-owned and franchisee-owned stores	(18) Corporate-owned and franchisee-owned stores The following table shows changes in our corporate-owned and franchisee-owned stores for the years ended December 31, 2017, 2016 and 2015: Year Ended December 31, 2017 2016 2015 Franchisee-owned stores: Stores operated at beginning of period 1,255 1,066 863 New stores opened 206 195 206 Stores debranded, sold or consolidated (1) (5 ) (6 ) (3 ) Stores operated at end of period 1,456 1,255 1,066 Corporate-owned stores: Stores operated at beginning of period 58 58 55 New stores opened 4 — 3 Stores acquired from franchisees — — — Stores operated at end of period 62 58 58 Total stores: Stores operated at beginning of period 1,313 1,124 918 New stores opened 210 195 209 Stores debranded, sold or consolidated (1) (5 ) (6 ) (3 ) Stores operated at end of period 1,518 1,313 1,124 (1) The term “debrand” refers to a franchisee-owned store whose right to use the Planet Fitness brand and marks has been terminated in accordance with the franchise agreement. We retain the right to prevent debranded stores from continuing to operate as fitness centers. The term “consolidated” refers to the combination of a franchisee’s store with another store located in close proximity with our prior approval. This often coincides with an enlargement, re-equipment and/or refurbishment of the remaining store.

Quarterly financial data (unaud

Quarterly financial data (unaudited)	12 Months Ended
	Dec. 31, 2017
Quarterly Financial Information Disclosure [Abstract]
Quarterly financial data (unaudited)	(19) Quarterly financial data (unaudited) For the quarter ended March 31, 2017 June 30, 2017 September 30, 2017 December 31, 2017 Total revenue $ 91,102 $ 107,316 $ 97,496 $ 134,028 Income from operations 33,055 38,250 33,954 42,277 Net income 17,866 18,004 18,902 829 Net income (loss) attributable to Planet Fitness, Inc. 8,842 12,412 15,345 (3,453 ) Earnings (loss) per share: Class A - Basic $ 0.14 $ 0.16 $ 0.18 $ (0.04 ) Class A - Diluted $ 0.14 $ 0.16 $ 0.18 $ (0.04 ) For the quarter ended March 31, 2016 June 30, 2016 September 30, 2016 December 31, 2016 Total revenue $ 83,343 $ 91,472 $ 87,007 $ 116,419 Income from operations 25,610 27,831 26,153 36,068 Net income 16,345 18,091 14,863 21,948 Net income attributable to Planet Fitness, Inc. 3,368 4,132 3,425 10,575 Earnings per share: Class A - Basic $ 0.09 $ 0.11 $ 0.08 $ 0.19 Class A - Diluted $ 0.09 $ 0.11 $ 0.08 $ 0.18

Subsequent events

Subsequent events	12 Months Ended
	Dec. 31, 2017
Subsequent Events [Abstract]
Subsequent events	(20) Subsequent events On January 1, 2018, the Company completed an asset purchase acquisition of a franchise group representing six franchise stores operating in Suffolk County, New York for approximately $28,600. On February 22, 2018, the Company’s board of directors approved an increase of $80,000 to our current $20,000 share repurchase program, bringing the total authorized amount available for repurchase to $100,000. The timing of the purchases and the amount of stock repurchased is subject to the Company’s discretion and will depend on market and business conditions, the Company’s general working capital needs, stock price, applicable legal requirements and other factors. The Company’s ability to repurchase shares at any particular time is also subject to continued compliance with the terms of our credit agreement. Purchases may be effected through one or more open market transactions, privately negotiated transactions, transactions structured through investment banking institutions, or a combination of the foregoing. The Company is not obligated under the program to acquire any particular amount of stock and can suspend or terminate the program at any time.

Valuation and Qualifying Accoun

Valuation and Qualifying Accounts	12 Months Ended
	Dec. 31, 2017
Valuation And Qualifying Accounts [Abstract]
Valuation and Qualifying Accounts	• Schedule II – Valuation and Qualifying Accounts (in thousands) Balance at Beginning of Period Provision for (recovery of) doubtful accounts, net Write-offs and other Balance at End of Period Allowance for doubtful accounts: December 31, 2017 $ 687 $ (19 ) $ (636 ) $ 32 December 31, 2016 629 58 - 687 December 31, 2015 399 650 (420 ) 629

Summary of significant accoun29

Summary of significant accounting policies (Policies)	12 Months Ended
	Dec. 31, 2017
Accounting Policies [Abstract]
Basis of presentation and consolidation	(a) Basis of presentation and consolidation The accompanying consolidated financial statements have been prepared in accordance with accounting principles generally accepted in the United States of America (“U.S. GAAP”) and pursuant to the rules and regulations of the Securities and Exchange Commission (the “SEC”). All significant intercompany balances and transactions have been eliminated in consolidation. As discussed in Note 1, as a result of the recapitalization transactions, Planet Fitness, Inc. consolidates Pla-Fit Holdings and Pla-Fit Holdings is considered to be the predecessor to Planet Fitness, Inc. for accounting and reporting purposes. The Company also consolidates entities in which it has a controlling financial interest, the usual condition of which is ownership of a majority voting interest. The Company also considers for consolidation certain interests where the controlling financial interest may be achieved through arrangements that do not involve voting interests. Such an entity, known as a variable interest entity (“VIE”), is required to be consolidated by its primary beneficiary. The primary beneficiary of a VIE is considered to possess the power to direct the activities of the VIE that most significantly impact its economic performance and has the obligation to absorb losses or the rights to receive benefits from the VIE that are significant to it. The principal entities in which the Company possesses a variable interest include franchise entities and certain other entities. The Company is not deemed to be the primary beneficiary for Planet Fitness franchise entities. Therefore, these entities are not consolidated. The results of the Company have been consolidated with Matthew Michael Realty LLC (“MMR”) and PF Melville LLC (“PF Melville”) based on the determination that the Company is the primary beneficiary with respect to these VIEs. These entities are real estate holding companies that derive a majority of their financial support from the Company through lease agreements for corporate stores. See Note 3 for further information related to the Company’s VIEs.
Use of estimates	(b) Use of estimates The preparation of financial statements in conformity with U.S. GAAP requires management to make estimates and assumptions that affect the amounts reported in the consolidated financial statements and accompanying notes. Although these estimates are based on management’s knowledge of current events and actions it may undertake in the future, they may ultimately differ from actual results. Significant areas where estimates and judgments are relied upon by management in the preparation of the consolidated financial statements include revenue recognition, valuation of equity-based compensation awards, the evaluation of the recoverability of goodwill and long-lived assets, including intangible assets, income taxes, including deferred tax assets and liabilities and reserves for unrecognized tax benefits, and the liability for the Company’s tax benefit arrangements.
Concentrations	(c) Concentrations Cash and cash equivalents are financial instruments, which potentially subject the Company to a concentration of credit risk. The Company invests its excess cash in several major financial institutions, which are insured by the Federal Deposit Insurance Corporation (FDIC) up to $250,000. The Company maintains balances in excess of these limits, but does not believe that such deposits with its banks are subject to any unusual risk. The credit risk associated with trade receivables is mitigated due to the large number of customers, generally our franchisees, and their broad dispersion over many different geographic areas. We do not have any concentrations with respect to our revenues. The Company purchases equipment, both for corporate-owned stores and for sales to franchisee-owned stores from various equipment vendors. For the year ended December 31, 2017 purchases from one equipment vendor comprised 91% of total equipment purchases. For the year ended December 31, 2016 purchases from two equipment vendors comprised 83% and 13%, respectively, of total equipment purchases and for the year ended December 31, 2015 purchases from two equipment vendors comprised 79% and 18%, respectively, of total equipment purchases. The Company, including Planet Fitness NAF, LLC (“NAF”) uses one primary vendor for advertising services. For the year ended December 31, 2017, purchases from this vendor comprised 63% of total equipment purchases. For the year ended December 31, 2016 purchases from two vendors comprised 25% and 16%, respectively, of total advertising purchases and for the year ended December 31, 2015 purchases from one vendor comprised 49% of total advertising purchases (see Note 4 for further discussion of NAF).
Cash and cash equivalents	(d) Cash and cash equivalents The Company considers all highly liquid investments purchased with an original maturity of 90 days or less to be cash equivalents. Cash held within the NAF is recorded as a restricted asset (see Note 4).
Revenue recognition	(e) Revenue recognition Franchise revenue The following revenues are generated as a result of transactions with or related to the Company’s franchisees. Area development fees Franchisees contractually enter into area development agreements (ADAs) to secure the exclusive right to open franchise stores within a defined geographical area. ADAs establish the timing and number of stores to be developed within the defined geographical area. Pursuant to an ADA, a franchisee is generally required to pay an initial nonrefundable development fee for a minimum number of stores to be developed, as outlined in the respective ADA. ADA fees collected in advance are deferred until the Company provides substantially all required obligations pursuant to the ADA. As the efforts and total cost relating to initial services are affected significantly by the number of stores opened in an area, the respective ADA is treated as a divisible contract. As each new site is accepted under an ADA, a franchisee signs a franchise operating agreement for the respective franchise location. As each store opened under an ADA typically has performance obligations associated with it, the Company recognizes ADA revenue as each individual franchise location is developed in proportion to the total number of stores to be developed under the ADA. These obligations are typically completed once the store is opened or the franchisee executes the individual property lease. As of December 31, 2017 and 2016, the deferred revenue for ADAs was $10,121 and $10,026, respectively. ADAs generally have an initial term equal to the number of years over which the franchisee is required to open franchise stores, which is typically 5 to 10 years. There is no right of refund for an executed ADA. Upon default, as defined in the agreement, the Company may reacquire the rights pursuant to an ADA, and all remaining deferred revenue is recognized at that time. Franchise fees and performance fees The Company generally charges an initial upfront nonrefundable franchise fee. Nonrefundable franchise fees are typically deferred until the franchisee executes a lease and receives initial training for the location, which is the point at which the Company has determined it has provided all of its material obligations required to recognize revenue. As of December 31, 2017 and 2016, the Company has recorded deferred franchise fees of $510 and $260, respectively, relating to stores to be opened in future years. These amounts are included in deferred revenue as of December 31, 2017 and 2016. The individual franchise agreements typically have a 10-year initial term, but provide the franchisee with an opportunity to enter into successive renewals subject to certain conditions. Transfer fees The Company’s current franchise agreement provides that upon the transfer of a Planet Fitness store to a different franchisee, the Company is entitled to a transfer fee in the amount of the greater of $25, or $10 per store being transferred, if more than one, in addition to reimbursement of out-of-pocket expenses, including external legal and administrative costs incurred in connection with the transfer. Transfer-related fees and expenses are due, payable, and recognized at the time the transfer is effectuated. Royalties Royalties, which represent recurring fees paid by franchisees based on the franchisee-owned stores’ monthly and annual membership billings, are recognized on a monthly basis over the term of the franchise agreement. As specified under certain franchise agreements, the Company recognizes additional royalty fees as the franchisee-owned stores attain contractual monthly membership billing threshold amounts. Beginning in 2010, for all new franchise agreements entered into pursuant to a newly executed ADA or outside an ADA, the Company began charging a fixed royalty percentage based upon gross membership billings. Other fees Online member join fees are paid to the Company by franchisees for processing new membership transactions when a new member signs up for a membership to a franchisee-owned store through the Company’s website. Billing transaction fees are paid to the Company for the processing of franchisee membership dues and annual fees through the Company’s third-party hosted point-of-sale system. Placement The Company is generally responsible for assembly and placement of equipment it sells to U.S. based franchisee-owned stores. Placement revenue is recognized upon completion and acceptance of the services at the franchise location. Commission income The Company recognizes commission income from its franchisees’ use of certain preferred vendor arrangements. Commissions are recognized when amounts have been earned and collectability from the vendor is reasonably assured. Corporate-owned stores revenue The following revenues are generated from stores owned and operated by the Company. Membership dues revenue Customers are offered multiple membership choices varying in length. Membership dues are earned and recognized over the membership term on a straight-line basis. Enrollment fee revenue Enrollment fees are charged to new members at the commencement of their membership. The Company recognizes enrollment fees ratably over the estimated duration of the membership life, which is generally two years. Annual membership fee revenue Annual membership fees are annual fees charged to members in addition to and in order to maintain low monthly membership dues. The Company recognizes annual membership fees ratably over the 12-month membership period. Retail sales The Company sells Planet Fitness branded apparel, food, beverages, and other accessories. The revenue for these items is recognized at the point of sale. Equipment revenue The Company sells and delivers equipment purchased from third-party equipment manufacturers to U.S. based franchisee-owned stores. Equipment revenue is recognized upon the equipment being delivered to and assembled at each store and accepted by the franchisee. Franchisees are charged for all freight costs incurred for the delivery of equipment. Freight revenue is recorded within equipment revenue and freight costs are recorded within cost of revenue. The Company recognizes revenue on a gross basis in these transactions as management has determined the Company to be the principal in these transactions. Management determined the Company to be the principal because the Company is the primary obligor in these transactions, the Company has latitude in establishing prices for the equipment sales to franchisees, the Company has supplier selection discretion and is involved in determination of product specifications, and the Company bears all credit risk associated with obligations to the equipment manufacturers. Equipment deposits are recognized as a liability on the accompanying consolidated balance sheets until delivery, assembly (if required), and acceptance by the franchisee. As of December 31, 2017 and 2016, equipment deposits were $6,498 and $2,170, respectively. Sales tax All revenue amounts are recorded net of applicable sales tax.
Deferred revenue	(f) Deferred revenue Deferred revenue represents cash received from franchisees for ADAs and franchise fees for which revenue recognition criteria has not yet been met and cash received from members for enrollment fees, membership dues and annual fees for the portion not yet earned based on the membership period.
Cost of revenue	(g) Cost of revenue Cost of revenue consists of direct costs associated with equipment sales (including freight costs), the cost of retail merchandise sold in corporate-owned stores, and prior to 2016 also included direct costs related to the maintenance and support of the Company’s proprietary system-wide point-of-sale system. Costs related to the point-of-sale system were $0, $0, and $1,236 for the years ended December 31, 2017, 2016 and 2015 respectively. Costs related to retail merchandise sales were immaterial in all periods presented. Rebates from equipment vendors where the Company has recognized the related equipment revenue and costs are recorded as a reduction to the cost of revenue.
Store operations	(h) Store operations Store operations consists of the direct costs related to operating corporate-owned stores, including our store management and staff, rent expense, utilities, supplies, maintenance, and local advertising.
Selling, general and administrative	(i) Selling, general and administrative Selling, general and administrative expenses consist of costs associated with administrative and franchisee support functions related to our existing business as well as growth and development activities. These costs primarily consist of payroll, IT related, marketing, legal and accounting expenses. These expenses include costs related to placement services of $4,601, $3,974, and $3,452, for the years ended December 31, 2017, 2016 and 2015, respectively.
Accounts and notes receivable	(j) Accounts receivable Accounts receivable is primarily comprised of amounts owed to the Company resulting from equipment, placement, and commission revenue. The Company evaluates its accounts receivable on an ongoing basis and may establish an allowance for doubtful accounts based on collections and current credit conditions. Accounts are written off as uncollectible when it is determined that further collection efforts will be unsuccessful. Historically, the Company has not had a significant amount of write-offs.
Leases and asset retirement obligations	(k) Leases and asset retirement obligations The Company recognizes rent expense related to leased office and operating space on a straight-line basis over the term of the lease. The difference between rent expense and rent paid, if any, as a result of escalation provisions and lease incentives, such as tenant improvements provided by lessors, and is recorded as deferred rent in the Company’s consolidated balance sheets. In accordance with ASC Topic 410, Asset Retirement and Environmental Obligations
Property and equipment	(l) Property and equipment Property and equipment is recorded at cost and depreciated using the straight-line method over its related estimated useful life. Leasehold improvements are amortized over the shorter of the lease term or the estimated useful life of the related asset, whichever is shorter. Upon sale or retirement, the asset cost and related accumulated depreciation are removed from the respective accounts, and any related gain or loss is reflected in the consolidated statements of operations. Ordinary maintenance and repair costs are expensed as incurred. The estimated useful lives of the Company’s fixed assets by class of asset are as follows: Years Buildings and building improvements 20–40 Computers and equipment 3-5 Furniture and fixtures 5 Leasehold improvements Useful life or term of lease whichever is shorter Fitness equipment 5–7 Vehicles 5
Advertising expenses	(m) Advertising expenses The Company expenses advertising costs as incurred. Advertising expenses, net of amounts reimbursed by franchisees, are included within store operations and selling, general and administrative expenses and totaled $9,906, $8,270, and $9,349 for the years ended December 31, 2017, 2016 and 2015, respectively. See Note 4 for discussion of the national advertising fund.
Goodwill, long-lived assets, and other intangible assets	(n) Goodwill, long-lived assets, and other intangible assets Goodwill and other intangible assets that arise from acquisitions are recorded in accordance with ASC Topic 350, Intangibles—Goodwill and Other Goodwill and indefinite-lived intangible assets are not amortized, but are reviewed annually for impairment or more frequently if impairment indicators arise. Separable intangible assets that are not deemed to have an indefinite life are amortized over their estimated useful lives on either a straight-line or accelerated basis as deemed appropriate, and are reviewed for impairment when events or circumstances suggest that the assets may not be recoverable. The Company performs its annual test for impairment of goodwill and indefinite lived intangible assets on December 31 of each year. For goodwill, the first step of the impairment test is to determine whether the carrying amount of a reporting unit exceeds the fair value of the reporting unit. If the carrying amount of the reporting unit exceeds the reporting unit’s fair value, the Company would be required to perform a second step of the impairment test as this is an indication that the reporting unit’s goodwill may be impaired. The second step compares the implied fair value of the reporting unit’s goodwill with the carrying amount of that goodwill. Any impairment loss would be recognized in an amount equal to the excess of the carrying value of the goodwill over the implied fair value of the goodwill. The Company is also permitted to make a qualitative assessment of whether it is more likely than not that a reporting unit’s fair value is less than its carrying amount before applying the two-step goodwill impairment test. If the Company concludes it is not more likely than not that the fair value of a reporting unit is less than its carrying amount, it need not perform the two-step impairment test. For indefinite lived intangible assets, the impairment assessment consists of comparing the carrying value of the asset to its estimated fair value. To the extent that the carrying value exceeds the fair value of the asset, an impairment is recorded to reduce the carrying value to its fair value. The Company is also permitted to make a qualitative assessment of whether it is more likely than not an indefinite lived intangible asset’s fair value is less than its carrying value prior to applying the quantitative assessment. If based on the Company’s qualitative assessment it is not more likely than not that the carrying value of the asset is less than its fair value, then a quantitative assessment is not required. The Company determined that no impairment charges were required during any periods presented. The Company applies the provisions of ASC Topic 360, Property, Plant and Equipment
Income taxes	(o) Income taxes The Company accounts for income taxes using the asset and liability method. Deferred income taxes are recognized for the expected future tax consequences attributable to temporary differences between the carrying amount of the existing tax assets and liabilities and their respective tax basis. Deferred tax assets and liabilities are measured using enacted tax rates expected to be applied in the years in which temporary differences are expected to be recovered or settled. The principal items giving rise to temporary differences are the use of accelerated depreciation and certain basis differences resulting from acquisitions and the recapitalization transactions. Valuation allowances are established when necessary to reduce deferred tax assets to the amount expected to be realized. As a result of the recapitalization transactions, Planet Fitness, Inc. became the sole managing member of Pla-Fit Holdings, which is treated as a partnership for U.S. federal and most applicable state and local income tax purposes. As a partnership, Pla-Fit Holdings is not subject to U.S. federal and certain state and local income taxes. Any taxable income or loss generated by Pla-Fit Holdings is passed through to and included in the taxable income or loss of its members, including Planet Fitness, Inc. following the recapitalization transactions, on a pro rata basis. Planet Fitness, Inc. is subject to U.S. federal income taxes, in addition to state and local income taxes with respect to our allocable share of any taxable income of Pla-Fit Holdings following the recapitalization transactions. The Company is also subject to taxes in foreign jurisdictions. The Company recognizes the effect of income tax positions only if those positions are more likely than not to be sustained. Recognized income tax positions are measured at the largest amount that is greater than 50% likely of being realized. Changes in recognition or measurement are reflected in the period in which the change in judgment occurs (see Note 14).
Tax benefit arrangements	(p) Tax benefit arrangements The Company’s acquisition of Holdings Units in connection with the IPO and future and certain past exchanges of Holdings Units for shares of the Company’s Class A common stock (or cash at the option of the Company) are expected to produce and have produced favorable tax attributes. In connection with the IPO, the Company entered into two tax receivable agreements. Under the first of those agreements, the Company generally is required to pay to certain existing and previous equity owners of Pla-Fit Holdings, LLC who are unaffiliated with TSG (the “TRA Holders”) 85% of the applicable tax savings, if any, in U.S. federal and state income tax that the Company is deemed to realize as a result of certain tax attributes of their Holdings Units sold to the Company (or exchanged in a taxable sale) and that are created as a result of (i) the sales of their Holdings Units for shares of Class A common stock and (ii) tax benefits attributable to payments made under the tax receivable agreement (including imputed interest). Under the second tax receivable agreement, the Company generally is required to pay to the Direct TSG Investors 85% of the amount of tax savings, if any, that the Company is deemed to realize as a result of the tax attributes of the Holdings Units held in respect of the Direct TSG Investors’ interest in the Company, which resulted from the Direct TSG Investors’ purchase of interests in Pla-Fit Holdings in 2012, and certain other tax benefits. Under both agreements, the Company generally retains the benefit of the remaining 15% of the applicable tax savings. Also, pursuant to the exchange agreement, to the extent an exchange results in Pla-Fit Holdings, LLC incurring a current tax liability relating to the New Hampshire business profits tax, the TRA Holders have agreed that they will contribute to Pla-Fit Holdings, LLC an amount sufficient to pay such tax liability (up to 3.5% of the value received upon exchange). If and when the Company subsequently realizes a related tax benefit, Pla-Fit Holdings, LLC will distribute the amount of any such tax benefit to the relevant Continuing LLC Owner in respect of its contribution. Due to changes in New Hampshire tax law, the Company no longer expects to incur any such liability under the New Hampshire business profits tax. Based on current projections, the Company anticipates having sufficient taxable income to utilize these tax attributes and receive corresponding tax deductions in future periods. Accordingly, as of December 31, 2017 the Company has recorded a liability of $431,360, which includes the impact of remeasurement related to the 2017 Tax Act, payable
Fair value	(q) Fair value ASC 820, Fair Value Measurements and Disclosures Level 1—Inputs to the valuation methodology are quoted prices (unadjusted) for identical assets or liabilities in active markets. Level 2—Inputs to the valuation methodology include quoted prices for similar assets and liabilities in active markets, and inputs that are observable for the asset or liability, either directly or indirectly, for substantially the full term of the financial instrument. Level 3—Inputs to the valuation methodology are unobservable and significant to the fair value measurement. The table below presents information about the Company’s assets and liabilities that are measured at fair value on a recurring basis as of December 31, 2017 and December 31, 2016: Quoted prices Significant Significant Total fair value at in active markets other observable unobservable December 31, 2017 markets (Level 1) inputs (Level 2) inputs (Level 3) Interest rate caps $ 340 $ — $ 340 $ — Quoted prices Significant Significant Total fair value at in active markets other observable unobservable December 31, 2016 markets (Level 1) inputs (Level 2) inputs (Level 3) Interest rate caps $ 306 $ — $ 306 $ —
Financial instruments	(r) Financial instruments The carrying values of cash and cash equivalents, accounts receivable and accounts payable approximate fair value because of the short-term nature of these instruments. The carrying value of debt also approximates fair value as it is variable rate debt.
Derivative instruments and hedging activities	(s) Derivative instruments and hedging activities The Company recognizes all derivative instruments as either assets or liabilities in the balance sheet at their respective fair values. For derivatives designated in hedging relationships, changes in the fair value are either offset through earnings against the change in fair value of the hedged item attributable to the risk being hedged or recognized in accumulated other comprehensive income, to the extent the derivative is effective at offsetting the changes in cash flows being hedged until the hedged item affects earnings. The Company only enters into derivative contracts that it intends to designate as a hedge of a forecasted transaction or the variability of cash flows to be received or paid related to a recognized asset or liability (cash flow hedge). For all hedging relationships, the Company formally documents the hedging relationship and its risk-management objective and strategy for undertaking the hedge, the hedging instrument, the hedged transaction, the nature of the risk being hedged, how the hedging instrument’s effectiveness in offsetting the hedged risk will be assessed prospectively and retrospectively, and a description of the method used to measure ineffectiveness. The Company also formally assesses, both at the inception of the hedging relationship and on an ongoing basis, whether the derivatives that are used in hedging relationships are highly effective in offsetting changes in cash flows of hedged transactions. For derivative instruments that are designated and qualify as part of a cash flow hedging relationship, the effective portion of the gain or loss on the derivative is reported as a component of other comprehensive income and reclassified into earnings in the same period or periods during which the hedged transaction affects earnings. Gains and losses on the derivative representing either hedge ineffectiveness or hedge components excluded from the assessment of effectiveness are recognized in current earnings. See Note 8 for further information.
Equity-based compensation	(t) Equity-based compensation The Company has an equity-based compensation plan under which it receives services from employees and directors as consideration for equity instruments of the Company. The compensation expense is determined based on the fair value of the award as of the grant date. Compensation expense is recognized over the vesting period, which is the period over which all of the specified vesting conditions are satisfied. For awards with graded vesting, the fair value of each tranche is recognized over its respective vesting period. The Company accounts for forfeitures as they occur by reversing compensation cost when the award is forfeited. See Note 12 for further information.
Guarantees	(u) Guarantees The Company, as a guarantor, is required to recognize, at inception of the guaranty, a liability for the fair value of the obligation undertaken in issuing the guarantee. See Notes 3 and 15 for further discussion of such obligations guaranteed.
Contingencies	(v) Contingencies The Company records estimated future losses related to contingencies when such amounts are probable and estimable. The Company includes estimated legal fees related to such contingencies as part of the accrual for estimated future losses.
Reclassifications	(w) Reclassifications Certain amounts have been reclassified to conform to current year presentation.
Recent accounting pronouncements	(x) Recent accounting pronouncements The FASB issued ASU No. 2014-09, Revenue from Contracts with Customers, The FASB issued ASU No. 2016-02, Leases The FASB issued ASU No. 2016-09, Stock Compensation The FASB issued ASU No. 2016-15, Classification of Certain Cash Receipts and Cash Payments The FASB issued ASU No. 2017-04, Simplifying the Test for Goodwill Impairment The FASB issued ASU No. 2017-12, Targeted Improvements to Accounting for Hedging Activities

Summary of significant accoun30

Summary of significant accounting policies (Tables)	12 Months Ended
	Dec. 31, 2017
Accounting Policies [Abstract]
Schedule of Estimated Useful Lives of Fixed Assets	The estimated useful lives of the Company’s fixed assets by class of asset are as follows: Years Buildings and building improvements 20–40 Computers and equipment 3-5 Furniture and fixtures 5 Leasehold improvements Useful life or term of lease whichever is shorter Fitness equipment 5–7 Vehicles 5
Summary of Company's Assets and Liabilities Measured at Fair Value on Recurring Basis	The table below presents information about the Company’s assets and liabilities that are measured at fair value on a recurring basis as of December 31, 2017 and December 31, 2016: Quoted prices Significant Significant Total fair value at in active markets other observable unobservable December 31, 2017 markets (Level 1) inputs (Level 2) inputs (Level 3) Interest rate caps $ 340 $ — $ 340 $ — Quoted prices Significant Significant Total fair value at in active markets other observable unobservable December 31, 2016 markets (Level 1) inputs (Level 2) inputs (Level 3) Interest rate caps $ 306 $ — $ 306 $ —

Variable interest entities (Tab

Variable interest entities (Tables)	12 Months Ended
	Dec. 31, 2017
Organization Consolidation And Presentation Of Financial Statements [Abstract]
Carrying Value of Variable Interest Entities of Consolidated Financial Statements	The carrying values of VIEs included in the consolidated financial statements as of December 31, 2017 and December 31, 2016 are as follows: December 31, 2017 December 31, 2016 Assets Liabilities Assets Liabilities PF Melville $ 4,420 $ — $ 4,071 $ — MMR $ 3,360 — $ 3,156 — Total $ 7,780 $ — $ 7,227 $ —

Property and equipment (Tables)

Property and equipment (Tables)	12 Months Ended
	Dec. 31, 2017
Property Plant And Equipment [Abstract]
Schedule of Property and Equipment	Property and equipment as of December 31, 2017 and 2016 consists of the following: December 31, 2017 December 31, 2016 Land $ 910 $ 910 Equipment 32,403 27,283 Leasehold improvements 60,181 41,249 Buildings and improvements 5,107 5,107 Furniture & fixtures 9,790 3,708 Other 7,923 5,673 Construction in progress 3,241 8,295 119,555 92,225 Accumulated Depreciation (36,228 ) (30,987 ) Total $ 83,327 $ 61,238

Goodwill and intangible assets

Goodwill and intangible assets (Tables)	12 Months Ended
	Dec. 31, 2017
Goodwill And Intangible Assets Disclosure [Abstract]
Summary of Goodwill and Intangible Assets	A summary of goodwill and intangible assets at December 31, 2017 and 2016 is as follows: Weighted average Gross amortization carrying Accumulated Net carrying December 31, 2017 period (years) amount amortization Amount Customer relationships 11.1 $ 171,782 (86,501 ) $ 85,281 Noncompete agreements 5.0 14,500 (14,500 ) — Favorable leases 7.5 2,935 (1,972 ) 963 Order backlog 0.4 3,400 (3,400 ) — Reacquired franchise rights 5.8 8,950 (5,837 ) 3,113 201,567 (112,210 ) 89,357 Indefinite-lived intangible: Trade and brand names N/A 146,300 — 146,300 Total intangible assets $ 347,867 $ (112,210 ) $ 235,657 Goodwill $ 176,981 $ — $ 176,981 Weighted average Gross amortization carrying Accumulated Net carrying December 31, 2016 period (years) amount amortization Amount Customer relationships 11.1 $ 171,782 (72,655 ) $ 99,127 Noncompete agreements 5.0 14,500 (12,027 ) 2,473 Favorable leases 7.5 2,935 (1,643 ) 1,292 Order backlog 0.4 3,400 (3,400 ) — Reacquired franchise rights 5.8 8,950 (4,280 ) 4,670 201,567 (94,005 ) 107,562 Indefinite-lived intangible: Trade and brand names N/A 146,300 — 146,300 Total intangible assets $ 347,867 $ (94,005 ) $ 253,862 Goodwill $ 176,981 $ — $ 176,981
Summary of Amortization expenses	The anticipated annual amortization expense to be recognized in future years as of December 31, 2017 is as follows: Amount 2018 $ 14,583 2019 14,215 2020 12,517 2021 12,422 2022 12,419 Thereafter 23,201 Total $ 89,357

Long-term debt (Tables)

Long-term debt (Tables)	12 Months Ended
	Dec. 31, 2017
Debt Disclosure [Abstract]
Schedule of Long-term Debt	Long-term debt as of December 31, 2017 and 2016 consists of the following: December 31, 2017 December 31, 2016 Term loan B requires quarterly installments plus interest through the term of the loan, maturing March 31, 2021. Outstanding borrowings bear interest at LIBOR or base rate (as defined) plus a margin at the election of the borrower (4.59% at December 31, 2017 and 4.33% at December 31, 2016) $ 709,470 $ 716,654 Revolving credit line, requires interest only payments through the term of the loan, maturing March 31, 2019. Outstanding borrowings bear interest at LIBOR or base rate (as defined) plus a margin at the election of the borrower (6.25% at December 31, 2017 and 6.0% at December 31, 2016) — — Total debt, excluding deferred financing costs 709,470 716,654 Deferred financing costs, net of accumulated amortization (5,709 ) (7,466 ) Total debt 703,761 709,188 Current portion of long-term debt and line of credit 7,185 7,185 Long-term debt, net of current portion $ 696,576 $ 702,003
Schedule of Future Annual Payments of Long-term Debt	Future annual principal payments of long-term debt as of December 31, 2017 are as follows: Amount 2018 $ 7,185 2019 7,185 2020 7,185 2021 687,915 2022 - Thereafter - Total $ 709,470

Deferred revenue (Tables)

Deferred revenue (Tables)	12 Months Ended
	Dec. 31, 2017
Deferred Revenue Disclosure [Abstract]
Schedule of Deferred Revenue	The summary set forth below represents the balances in deferred revenue as of December 31, 2017 and 2016: December 31, 2017 December 31, 2016 Prepaid membership fees $ 5,198 $ 5,034 Enrollment fees 1,014 1,240 Equipment discount 2,567 2,796 Annual membership fees 8,113 6,775 Area development and franchise fees 10,631 10,286 Total deferred revenue 27,523 26,131 Long-term portion of deferred revenue 8,440 8,351 Current portion of deferred revenue $ 19,083 $ 17,780

Related party transactions (Tab

Related party transactions (Tables)	12 Months Ended
	Dec. 31, 2017
Related Party Transactions [Abstract]
Schedule of Related Party Transactions	Activity with franchisees considered to be related parties is summarized below. For the Year Ended December 31, 2017 2016 2015 Franchise revenue $ 2,130 $ 1,760 $ 1,232 Equipment revenue 3,464 1,338 1,686 Total revenue from related parties $ 5,594 $ 3,098 $ 2,918

Equity-based Compensation (Tabl

Equity-based Compensation (Tables)	12 Months Ended
	Dec. 31, 2017
Summary of Unvested Holdings Unit Activity	A summary of unvested Holdings Unit activity is presented below: Holdings Units Weighted average grant date fair value Weighted average remaining contractual term (years) Aggregate intrinsic value Unvested outstanding at January 1, 2017 1,025,016 $ 1.52 Units granted — — Units forfeited (150,181 ) $ 1.52 Units vested (604,614 ) $ 1.52 Unvested outstanding at December 31, 2017 270,221 $ 1.52 0.7 $ 9,358
Summary of Stock Option Activity	A summary of stock option activity for the year ended December 31, 2017: Stock Options Weighted exercise price Weighted average remaining contractual term (years) Aggregate intrinsic value Outstanding at January 1, 2017 404,470 $ 17.49 Granted 617,904 $ 20.97 Exercised (27,191 ) $ 17.63 Forfeited (76,977 ) $ 20.32 Outstanding at December 31, 2017 918,206 $ 19.59 8.7 $ 13,811 Vested or expected to vest at December 31, 2017 918,206 $ 19.59 8.7 $ 13,811 Exercisable at December 31, 2017 90,046 $ 17.23 8.2 $ 1,567
Restricted Stock Units [Member]
Summary of Restricted Stock Units Activity (Detail)	Stock Options Weighted fair value Weighted average remaining contractual term (years) Aggregate intrinsic value Unvested outstanding at January 1, 2017 7,887 $ 19.02 Granted 13,498 $ 24.25 Vested (5,167 ) $ 19.35 Unvested outstanding at December 31, 2017 16,218 $ 23.26 0.6 $ 462
2015 Omnibus Incentive Plan [Member]
Fair Value of Stock Option Awards Determined on Grant Date	The fair value of stock option awards granted were determined on the grant date using the Black-Scholes valuation model based on the following assumptions: Year ended December 31, 2017 2016 Expected term (years) (1) 6.25 6.25 Expected volatility (2) 28.6% - 32.9% 33.2% - 34.4% Risk-free interest rate (3) 1.86% - 2.10% 1.31% - 1.76% Dividend yield (4) — — (1) Expected term represents the estimated period of time until an award is exercised and was determined using the simplified method. (2) Expected volatility is based on the historical volatility of a selected peer group over a period equivalent to the expected term. (3) The risk-free rate is an interpolation of yields on U.S. Treasury securities with maturities equivalent to the expected term. (4) Based on an assumed a dividend yield of zero at the time of grant.

Earnings per share (Tables)

Earnings per share (Tables)	12 Months Ended
	Dec. 31, 2017
Class A Common Stock [Member]
Earnings Per Share Basic [Line Items]
Reconciliation of Numerators and Denominators Used to Compute Basic and Diluted Earnings per Share	The following table sets forth reconciliations of the numerators and denominators used to compute basic and diluted earnings per share of Class A common stock: Basic net income per share: Year ended December 31, 2017 Year ended December 31, 2016 August 6, 2015 through December 31, 2015 Numerator Net income $ 55,601 $ 71,247 $ 23,454 Less: net income attributable to non-controlling interests 22,455 49,747 19,348 Net income attributable to Planet Fitness, Inc. - basic & diluted $ 33,146 $ 21,500 $ 4,106 Denominator Weighted-average shares of Class A common stock outstanding - basic 78,910,390 43,300,288 36,243,557 Effect of dilutive securities: Stock options 56,198 1,489 — Restricted stock units 4,962 2,908 — Weighted-average shares of Class A common stock outstanding - diluted 78,971,550 43,304,685 36,243,557 Earnings per share of Class A common stock - basic $ 0.42 $ 0.50 $ 0.11 Earnings per share of Class A common stock - diluted $ 0.42 $ 0.50 $ 0.11

Income taxes (Tables)

Income taxes (Tables)	12 Months Ended
	Dec. 31, 2017
Income Tax Disclosure [Abstract]
Schedule of Income Before Provision for Income Taxes	Income before the provision for income taxes as shown in the accompanying consolidated statements of operations is as follows: Year Ended December 31, 2017 2016 2015 Domestic $ 426,873 $ 88,016 $ 48,716 Foreign 2,308 1,892 (1,438 ) Total income before the provision for income taxes 429,181 89,908 47,278
Schedule of Provision (Benefit) for Income Taxes	The provision (benefit) for income taxes consists of the following: Year Ended December 31, 2017 2016 2015 Current: Federal $ (2,600 ) $ 1,206 $ 686 State 2,941 1,428 2,188 Foreign 817 421 139 Total current tax expense 1,158 3,055 3,013 Deferred: Federal 365,470 11,633 5,636 State 6,857 3,755 935 Foreign 95 218 (436 ) Total deferred tax expense 372,422 15,606 6,135 Provision for income taxes $ 373,580 $ 18,661 $ 9,148
Schedule of Reconciliation of U.S. Statutory Income Tax Rate to Company's Effective Tax Rate	A reconciliation of the U.S. statutory income tax rate to the Company’s effective tax rate is as follows: Year Ended December 31, 2017 2016 2015 U.S. statutory tax rate 35.0 % 35.0 % 35.0 % State and local taxes, net of federal benefit 1.0 % 4.9 % 6.2 % State rate change impact on deferred taxes 0.8 % (1.4 )% 6.9 % Federal rate change impact on deferred taxes 77.8 % — % — % Tax benefit arrangement liability adjustment (25.8 )% — % (2.1 )% Foreign tax rate differential — % (0.3 )% 0.3 % Withholding taxes and other 0.1 % — % 0.2 % Reserve for uncertain tax position 0.1 % 3.1 % — % Income attributable to non-controlling interests (1.9 )% (20.5 )% (27.1 )% Effective tax rate 87.1 % 20.8 % 19.4 %
Schedule of Deferred Tax Assets and Liabilities	Details of the Company’s deferred tax assets and liabilities are summarized as follows: Year Ended December 31, 2017 2016 Deferred tax assets: Accrued expense and reserves $ 1,422 $ 865 Deferred revenue 1,900 2,029 Goodwill and intangible assets 404,547 406,447 Net operating loss 603 22 Other 3,619 4,218 Deferred tax assets $ 412,091 $ 413,581 Deferred tax liabilities: Prepaid expenses (773 ) (781 ) Property and equipment (5,165 ) (3,631 ) Total deferred tax liabilities $ (5,938 ) $ (4,412 ) Total deferred tax assets and liabilities $ 406,153 $ 409,169 Reported as: Deferred income taxes - non-current assets $ 407,782 $ 410,407 Deferred income taxes - non-current liabilities (1,629 ) (1,238 ) Total deferred tax assets and liabilities $ 406,153 $ 409,169
Summary Of Changes In Unrecognized Tax Positions	A summary of the changes in the Company’s unrecognized tax positions is as follows: Year Ended December 31, 2017 2016 Balance at beginning of year $ 2,608 $ 300 Increases related to prior year tax positions — 2,308 Balance at end of year $ 2,608 $ 2,608
Schedule of Future Payments Under Tax Benefit Arrangements	Projected future payments under the tax benefit arrangements are as follows: Amount 2018 $ 31,062 2019 23,298 2020 23,596 2021 24,010 2022 24,482 Thereafter 304,912 Total $ 431,360

Commitments and contingencies (

Commitments and contingencies (Tables)	12 Months Ended
	Dec. 31, 2017
Commitments And Contingencies Disclosure [Abstract]
Schedule of Future Commitments Under Noncancelable Operating Leases	Approximate annual future commitments under noncancelable operating leases as of December 31, 2017 are as follows Amount 2018 $ 14,563 2019 13,439 2020 12,495 2021 10,747 2022 9,993 Thereafter 48,712 Total $ 109,949

Segments (Tables)

Segments (Tables)	12 Months Ended
	Dec. 31, 2017
Segment Reporting [Abstract]
Summary of Financial Information for the Company's Reportable Segments	The tables below summarize the financial information for the Company’s reportable segments for the years ended December 31, 2017, 2016 and 2015. The “Corporate and other” column, as it relates to Segment EBITDA, primarily includes corporate overhead costs, such as payroll and related benefit costs and professional services which are not directly attributable to any individual segment. Year Ended December 31, 2017 2016 2015 Revenue Franchise segment revenue - U.S. $ 147,787 $ 114,717 $ 87,299 Franchise segment revenue - International 2,368 1,771 786 Franchise segment total 150,155 116,488 88,085 Corporate-owned stores segment - U.S. 107,712 100,541 95,459 Corporate-owned stores segment - International 4,402 4,180 2,931 Corporate-owned stores segment total 112,114 104,721 98,390 Equipment segment - U.S. 167,673 157,032 144,062 Equipment segment total 167,673 157,032 144,062 Total revenue $ 429,942 $ 378,241 $ 330,537 Year Ended December 31, 2017 2016 2015 Segment EBITDA Franchise $ 126,459 $ 97,256 $ 66,030 Corporate-owned stores 46,855 40,847 36,070 Equipment 38,539 36,439 31,936 Corporate and other 284,372 (26,007 ) (30,051 ) Total Segment EBITDA $ 496,225 $ 148,535 $ 103,985
Reconciliation of Total Segment EBITDA to Income Before Taxes	The following table reconciles total Segment EBITDA to income before taxes: Year Ended December 31, 2017 2016 2015 Total Segment EBITDA $ 496,225 $ 148,535 $ 103,985 Less: Depreciation and amortization 31,761 31,502 32,158 Other expense 316,928 1,371 (275 ) Income from operations 147,536 115,662 72,102 Interest expense, net (35,283 ) (27,125 ) (24,549 ) Other income (expense) 316,928 1,371 (275 ) Income before income taxes $ 429,181 $ 89,908 $ 47,278
Summary of Company's Assets by Reportable Segment	The following table summarizes the Company’s assets by reportable segment: December 31, 2017 December 31, 2016 Franchise $ 243,348 $ 202,580 Corporate-owned stores 167,367 153,761 Equipment 206,632 208,809 Unallocated 475,118 436,292 Total consolidated assets $ 1,092,465 $ 1,001,442
Summary of Company's Goodwill by Reportable Segment	The following table summarizes the Company’s goodwill by reportable segment: December 31, 2017 December 31, 2016 Franchise $ 16,938 $ 16,938 Corporate-owned stores 67,377 67,377 Equipment 92,666 92,666 Total consolidated goodwill $ 176,981 $ 176,981

Corporate-owned and franchise42

Corporate-owned and franchisee-owned stores (Tables)	12 Months Ended
	Dec. 31, 2017
Other Industries [Abstract]
Schedule of Changes in Corporate-owned and Franchisee-owned Stores	The following table shows changes in our corporate-owned and franchisee-owned stores for the years ended December 31, 2017, 2016 and 2015: Year Ended December 31, 2017 2016 2015 Franchisee-owned stores: Stores operated at beginning of period 1,255 1,066 863 New stores opened 206 195 206 Stores debranded, sold or consolidated (1) (5 ) (6 ) (3 ) Stores operated at end of period 1,456 1,255 1,066 Corporate-owned stores: Stores operated at beginning of period 58 58 55 New stores opened 4 — 3 Stores acquired from franchisees — — — Stores operated at end of period 62 58 58 Total stores: Stores operated at beginning of period 1,313 1,124 918 New stores opened 210 195 209 Stores debranded, sold or consolidated (1) (5 ) (6 ) (3 ) Stores operated at end of period 1,518 1,313 1,124 (1) The term “debrand” refers to a franchisee-owned store whose right to use the Planet Fitness brand and marks has been terminated in accordance with the franchise agreement. We retain the right to prevent debranded stores from continuing to operate as fitness centers. The term “consolidated” refers to the combination of a franchisee’s store with another store located in close proximity with our prior approval. This often coincides with an enlargement, re-equipment and/or refurbishment of the remaining store.

Quarterly financial data (una43

Quarterly financial data (unaudited) (Tables)	12 Months Ended
	Dec. 31, 2017
Quarterly Financial Information Disclosure [Abstract]
Schedule of Quarterly Financial Data	For the quarter ended March 31, 2017 June 30, 2017 September 30, 2017 December 31, 2017 Total revenue $ 91,102 $ 107,316 $ 97,496 $ 134,028 Income from operations 33,055 38,250 33,954 42,277 Net income 17,866 18,004 18,902 829 Net income (loss) attributable to Planet Fitness, Inc. 8,842 12,412 15,345 (3,453 ) Earnings (loss) per share: Class A - Basic $ 0.14 $ 0.16 $ 0.18 $ (0.04 ) Class A - Diluted $ 0.14 $ 0.16 $ 0.18 $ (0.04 ) For the quarter ended March 31, 2016 June 30, 2016 September 30, 2016 December 31, 2016 Total revenue $ 83,343 $ 91,472 $ 87,007 $ 116,419 Income from operations 25,610 27,831 26,153 36,068 Net income 16,345 18,091 14,863 21,948 Net income attributable to Planet Fitness, Inc. 3,368 4,132 3,425 10,575 Earnings per share: Class A - Basic $ 0.09 $ 0.11 $ 0.08 $ 0.19 Class A - Diluted $ 0.09 $ 0.11 $ 0.08 $ 0.18

Business Organization - Additio

Business Organization - Additional Information (Detail) $ / shares in Units, $ in Thousands	May 10, 2017$ / sharesshares	Mar. 14, 2017$ / sharesshares	Nov. 22, 2016$ / sharesshares	Sep. 28, 2016$ / sharesshares	Jun. 28, 2016$ / sharesshares	Aug. 11, 2015USD ($)$ / sharesshares	Aug. 05, 2015shares	May 31, 2017$ / sharesshares	Mar. 31, 2017$ / sharesshares	Nov. 30, 2016$ / sharesshares	Sep. 30, 2016$ / sharesshares	Jun. 30, 2016$ / sharesshares	Dec. 31, 2017MemberStoreStateshares	Dec. 31, 2016Storeshares	Dec. 31, 2015USD ($)Storeshares	Nov. 27, 2016	Sep. 27, 2016	Jun. 27, 2016	Dec. 31, 2014Store
Organization Consolidation And Presentation Of Financial Statements Disclosure [Line Items]
Number of members | Member													10,600,000
Number of owned and franchised locations | Store													1,518	1,313	1,124				918
Number of states in which entity operates | State													50
Date of formation													Mar. 16, 2015
Proceeds from issuance of Class A common stock sold in initial public offering, net of underwriting discounts and commissions | $															$ 156,946
Continuing LLC Owners [Member]
Organization Consolidation And Presentation Of Financial Statements Disclosure [Line Items]
Percentage of economic interest													11.40%
Stock issued during period, shares, conversion of units													4,762,943	1,271,146
Secondary Offering [Member] | Continuing LLC Owners [Member]
Organization Consolidation And Presentation Of Financial Statements Disclosure [Line Items]
Percentage of economic interest			38.20%								49.40%	54.90%				48.50%	54.90%	62.90%
Class A Common Stock [Member]
Organization Consolidation And Presentation Of Financial Statements Disclosure [Line Items]
Number of stock issued during period	16,085,510	15,000,000	15,000,000	8,000,000	11,500,000								4,762,943	1,271,146	10,491,000
Share price | $ / shares	$ 20.28	$ 20.44	$ 23.22	$ 19.62	$ 16.50
Stock issued during period, shares, conversion of units													25,842,000	24,705,000
Class A Common Stock [Member] | Continuing LLC Owners [Member]
Organization Consolidation And Presentation Of Financial Statements Disclosure [Line Items]
Number of stock issued during period	10,869,819	10,209,242	10,136,285	5,406,019	7,891,160								4,762,943	1,271,146
Number of shares exchanged													25,842,004	24,704,610
Class A Common Stock [Member] | Direct TSG Investors [Member]
Organization Consolidation And Presentation Of Financial Statements Disclosure [Line Items]
Number of stock issued during period	5,215,691	4,790,758	4,863,715	2,593,981	3,608,840	5,033,945
Class A Common Stock [Member] | Secondary Offering [Member]
Organization Consolidation And Presentation Of Financial Statements Disclosure [Line Items]
Number of stock issued during period								16,085,510	15,000,000	15,000,000	8,000,000	11,500,000
Share price | $ / shares								$ 20.28	$ 20.44	$ 23.22	$ 19.62	$ 16.50
Class A Common Stock [Member] | Secondary Offering [Member] | Continuing LLC Owners [Member]
Organization Consolidation And Presentation Of Financial Statements Disclosure [Line Items]
Number of stock issued during period										10,136,285	5,406,019	7,891,160
Class A Common Stock [Member] | Secondary Offering [Member] | Direct TSG Investors [Member]
Organization Consolidation And Presentation Of Financial Statements Disclosure [Line Items]
Number of stock issued during period								5,215,691	4,790,758	4,863,715	2,593,981	3,608,840
Class A Common Stock [Member] | Secondary Offering [Member] | Holdings Units [Member]
Organization Consolidation And Presentation Of Financial Statements Disclosure [Line Items]
Number of stock issued during period								10,869,819	10,209,242
Class B Common Stock [Member]
Organization Consolidation And Presentation Of Financial Statements Disclosure [Line Items]
Number of shares exchanged													4,762,943	1,271,146
Class B Common Stock [Member] | Continuing LLC Owners [Member]
Organization Consolidation And Presentation Of Financial Statements Disclosure [Line Items]
Number of stock issued during period							72,602,810
Number of shares exchanged	10,869,819	10,209,242	10,136,285	5,406,019	7,891,160								4,762,943	1,271,146
Class B Common Stock [Member] | Secondary Offering [Member] | Continuing LLC Owners [Member]
Organization Consolidation And Presentation Of Financial Statements Disclosure [Line Items]
Number of shares exchanged										10,136,285	5,406,019	7,891,160
Class B Common Stock [Member] | Secondary Offering [Member] | Holdings Units [Member]
Organization Consolidation And Presentation Of Financial Statements Disclosure [Line Items]
Number of shares exchanged								10,869,819	10,209,242
Pla-Fit Holdings, LLC [Member]
Organization Consolidation And Presentation Of Financial Statements Disclosure [Line Items]
Percentage of ownership							100.00%						100.00%
Percentage of economic interest													88.60%
Pla-Fit Holdings, LLC [Member]
Organization Consolidation And Presentation Of Financial Statements Disclosure [Line Items]
Number of units held by owners	10,869,819	10,209,242	10,136,285	5,406,019	7,891,160								4,762,943	1,271,146
Pla-Fit Holdings, LLC [Member] | Secondary Offering [Member]
Organization Consolidation And Presentation Of Financial Statements Disclosure [Line Items]
Percentage of ownership			100.00%								100.00%	100.00%				100.00%	100.00%	100.00%
Number of units held by owners								10,869,819	10,209,242	10,136,285	5,406,019	7,891,160
Percentage of economic interest			61.80%								50.60%	45.10%				51.50%	45.10%	37.10%
Pla-Fit Holdings, LLC [Member] | Class A Common Stock [Member] | IPO [Member]
Organization Consolidation And Presentation Of Financial Statements Disclosure [Line Items]
Number of stock issued during period						15,525,000
Share price | $ / shares						$ 16
Pla-Fit Holdings, LLC [Member] | Class A Common Stock [Member] | IPO [Member] | Continuing LLC Owners [Member]
Organization Consolidation And Presentation Of Financial Statements Disclosure [Line Items]
Number of stock issued during period						10,491,055
Proceeds from issuance of Class A common stock sold in initial public offering, net of underwriting discounts and commissions | $						$ 156,946
Pla-Fit Holdings, LLC [Member] | Class B Common Stock [Member] | Continuing LLC Owners [Member]
Organization Consolidation And Presentation Of Financial Statements Disclosure [Line Items]
Number of stock issued during period							72,602,810
Pla-Fit Holdings, LLC [Member] | Planet Intermediate, LLC [Member]
Organization Consolidation And Presentation Of Financial Statements Disclosure [Line Items]
Percentage of ownership							100.00%
Planet Intermediate, LLC [Member] | Planet Fitness Holdings, LLC [Member]
Organization Consolidation And Presentation Of Financial Statements Disclosure [Line Items]
Percentage of ownership							100.00%

Summary of Significant Accoun45

Summary of Significant Accounting Policies - Additional Information (Detail)	12 Months Ended
	Dec. 31, 2017USD ($)VendorAgreement	Dec. 31, 2016USD ($)Vendor	Dec. 31, 2015USD ($)Vendor	Jan. 01, 2018USD ($)
Significant Accounting Policies [Line Items]
Deferred revenue	$ 27,523,000	$ 26,131,000
Membership enrollment fees recognition period	2 years
Membership fees recognition period	12 months
Equipment deposits	$ 6,498,000	2,170,000
Cost of revenue	129,266,000	122,317,000	$ 113,492,000
Selling, general and administrative	60,369,000	50,008,000	55,573,000
Impairment charges	$ 0	0
Income tax positions	Recognized income tax positions are measured at the largest amount that is greater than 50% likely of being realized.
Number of tax receivable agreements | Agreement	2
Applicable tax savings	85.00%
Percentage of remaining tax savings	15.00%
Income tax rate maximum tax liability	3.50%
ASU No. 2014-09 [Member] | Subsequent Event [Member]
Significant Accounting Policies [Line Items]
Deferred incremental revenue upon adoption of guidance				$ 13,500,000
Expected incremental revenues and expenses upon adoption of guidance				$ 45,000,000
TRA Holders [Member]
Significant Accounting Policies [Line Items]
Liability payable under tax benefit obligations	$ 431,360,000
Selling, General and Administrative Expenses [Member]
Significant Accounting Policies [Line Items]
Advertising expenses	9,906,000	8,270,000	9,349,000
Point of Sale System [Member]
Significant Accounting Policies [Line Items]
Cost of revenue	0	0	1,236,000
Placement Services [Member]
Significant Accounting Policies [Line Items]
Selling, general and administrative	4,601,000	3,974,000	$ 3,452,000
Area Development Agreements [Member]
Significant Accounting Policies [Line Items]
Deferred revenue	10,121,000	10,026,000
Franchise Fees [Member]
Significant Accounting Policies [Line Items]
Deferred revenue	$ 510,000	$ 260,000
Individual Franchise Agreements [Member]
Significant Accounting Policies [Line Items]
Franchisee initial term	10 years
Equipment Purchase [Member] | Supplier Concentration Risk [Member]
Significant Accounting Policies [Line Items]
Number of vendors | Vendor	1	2	2
Equipment Purchase [Member] | Supplier Concentration Risk [Member] | Vendor One [Member]
Significant Accounting Policies [Line Items]
Purchases from vendor	91.00%	83.00%	79.00%
Equipment Purchase [Member] | Supplier Concentration Risk [Member] | Vendor Two [Member]
Significant Accounting Policies [Line Items]
Purchases from vendor		13.00%	18.00%
Advertising Purchase [Member] | Supplier Concentration Risk [Member]
Significant Accounting Policies [Line Items]
Number of vendors | Vendor	1	2	1
Advertising Purchase [Member] | Supplier Concentration Risk [Member] | Vendor One [Member]
Significant Accounting Policies [Line Items]
Purchases from vendor	63.00%	25.00%	49.00%
Advertising Purchase [Member] | Supplier Concentration Risk [Member] | Vendor Two [Member]
Significant Accounting Policies [Line Items]
Purchases from vendor		16.00%
Maximum [Member]
Significant Accounting Policies [Line Items]
Insured amount	$ 250,000,000
Maximum [Member] | Area Development Agreements [Member]
Significant Accounting Policies [Line Items]
Franchisee initial term	10 years
Maximum [Member] | Transfer Fees [Member]
Significant Accounting Policies [Line Items]
Deferred revenue	$ 25,000
Minimum [Member] | Area Development Agreements [Member]
Significant Accounting Policies [Line Items]
Franchisee initial term	5 years
Minimum [Member] | Transfer Fees [Member]
Significant Accounting Policies [Line Items]
Deferred revenue	$ 10,000

Summary of Significant Accoun46

Summary of Significant Accounting Policies - Summary of Estimated Useful Lives of Company's Fixed assets (Detail)	12 Months Ended
	Dec. 31, 2017
Building and Building Improvements [Member] | Minimum [Member]
Significant Accounting Policies [Line Items]
Property, plant and equipment, estimated useful lives	20 years
Building and Building Improvements [Member] | Maximum [Member]
Significant Accounting Policies [Line Items]
Property, plant and equipment, estimated useful lives	40 years
Computer and Equipment [Member] | Minimum [Member]
Significant Accounting Policies [Line Items]
Property, plant and equipment, estimated useful lives	3 years
Computer and Equipment [Member] | Maximum [Member]
Significant Accounting Policies [Line Items]
Property, plant and equipment, estimated useful lives	5 years
Furniture and Fixtures [Member]
Significant Accounting Policies [Line Items]
Property, plant and equipment, estimated useful lives	5 years
Leasehold Improvements [Member]
Significant Accounting Policies [Line Items]
Property, plant and equipment, estimated useful lives	Useful life or term of lease whichever is shorter
Fitness Equipment [Member] | Minimum [Member]
Significant Accounting Policies [Line Items]
Property, plant and equipment, estimated useful lives	5 years
Fitness Equipment [Member] | Maximum [Member]
Significant Accounting Policies [Line Items]
Property, plant and equipment, estimated useful lives	7 years
Vehicles [Member]
Significant Accounting Policies [Line Items]
Property, plant and equipment, estimated useful lives	5 years

Summary of Significant Accoun47

Summary of Significant Accounting Policies - Summary of Company's Assets and Liabilities Measured at Fair Value on Recurring Basis (Detail) - Interest Rate Cap [Member] - Fair Value Measurements Recurring - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Interest rate caps	$ 340	$ 306
Significant Other Observable Inputs (Level 2) [Member]
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Interest rate caps	$ 340	$ 306

Variable Interest Entities - Ca

Variable Interest Entities - Carrying Value of Variable Interest Entities of Consolidated Financial Statements (Detail) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Variable Interest Entity [Line Items]
Assets	$ 7,780	$ 7,227
PF Melville [Member]
Variable Interest Entity [Line Items]
Assets	4,420	4,071
MMR [Member]
Variable Interest Entity [Line Items]
Assets	$ 3,360	$ 3,156

Variable Interest Entities - Ad

Variable Interest Entities - Additional Information (Detail) - USD ($)	Dec. 31, 2017	Dec. 31, 2016
Variable Interest Entity Consolidated Carrying Amount Assets And Liabilities [Abstract]
Maximum obligation of guarantees of leases and debt	$ 979,000	$ 1,350,000
Maximum loss exposure Involvement of estimated value	$ 0

National Advertising Fund - Add

National Advertising Fund - Additional Information (Detail) - Planet Fitness NAF, LLC [Member] - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Related Party Transaction [Line Items]
Percentage of franchise membership billing revenue	2.00%
Percentage of monthly membership billing contribution	2.00%
Initial administrative fees charged	$ 2,150	$ 1,700	$ 1,340

Property and Equipment - Schedu

Property and Equipment - Schedule of Property and Equipment (Detail) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Property, Plant and Equipment [Line Items]
Property and equipment, gross	$ 119,555	$ 92,225
Accumulated Depreciation	(36,228)	(30,987)
Total	83,327	61,238
Land [Member]
Property, Plant and Equipment [Line Items]
Property and equipment, gross	910	910
Equipment [Member]
Property, Plant and Equipment [Line Items]
Property and equipment, gross	32,403	27,283
Leasehold Improvements [Member]
Property, Plant and Equipment [Line Items]
Property and equipment, gross	60,181	41,249
Buildings and Improvements [Member]
Property, Plant and Equipment [Line Items]
Property and equipment, gross	5,107	5,107
Furniture and Fixtures [Member]
Property, Plant and Equipment [Line Items]
Property and equipment, gross	9,790	3,708
Other [Member]
Property, Plant and Equipment [Line Items]
Property and equipment, gross	7,923	5,673
Construction in Progress [Member]
Property, Plant and Equipment [Line Items]
Property and equipment, gross	$ 3,241	$ 8,295

Property and Equipment - Additi

Property and Equipment - Additional Information (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Property, Plant and Equipment [Abstract]
Depreciation expense	$ 13,886	$ 12,131	$ 11,088

Goodwill and Intangible Asset53

Goodwill and Intangible Assets - Summary of Goodwill and Intangible Assets (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
Goodwill And Intangible Assets [Line Items]
Gross carrying amount	$ 201,567	$ 201,567
Accumulated amortization	(112,210)	(94,005)
Net carrying Amount	89,357	107,562
Total intangible assets, Gross carrying amount	347,867	347,867
Total intangible assets, Net carrying Amount	235,657	253,862
Goodwill, Gross carrying amount	176,981	176,981
Goodwill, Net carrying Amount	176,981	176,981
Trade and Brand Names [Member]
Goodwill And Intangible Assets [Line Items]
Indefinite-lived intangible, Net carrying Amount	$ 146,300	$ 146,300
Customer Relationships [Member]
Goodwill And Intangible Assets [Line Items]
Weighted average amortization period (years)	11 years 1 month 6 days	11 years 1 month 6 days
Gross carrying amount	$ 171,782	$ 171,782
Accumulated amortization	(86,501)	(72,655)
Net carrying Amount	$ 85,281	$ 99,127
Noncompete Agreements [Member]
Goodwill And Intangible Assets [Line Items]
Weighted average amortization period (years)	5 years	5 years
Gross carrying amount	$ 14,500	$ 14,500
Accumulated amortization	$ (14,500)	(12,027)
Net carrying Amount		$ 2,473
Favorable Leases [Member]
Goodwill And Intangible Assets [Line Items]
Weighted average amortization period (years)	7 years 6 months	7 years 6 months
Gross carrying amount	$ 2,935	$ 2,935
Accumulated amortization	(1,972)	(1,643)
Net carrying Amount	$ 963	$ 1,292
Order Backlog [Member]
Goodwill And Intangible Assets [Line Items]
Weighted average amortization period (years)	4 months 24 days	4 months 24 days
Gross carrying amount	$ 3,400	$ 3,400
Accumulated amortization	$ (3,400)	$ (3,400)
Reacquired Franchise Rights [Member]
Goodwill And Intangible Assets [Line Items]
Weighted average amortization period (years)	5 years 9 months 18 days	5 years 9 months 18 days
Gross carrying amount	$ 8,950	$ 8,950
Accumulated amortization	(5,837)	(4,280)
Net carrying Amount	$ 3,113	$ 4,670

Goodwill and Intangible Asset54

Goodwill and Intangible Assets - Additional Information (Detail) - USD ($)	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Goodwill And Intangible Assets [Line Items]
Changes in carrying amount of goodwill	$ 0	$ 0
Impairment charges	0	0
Amortization of intangible assets	18,205,000	19,757,000	$ 21,543,000
Favorable And Unfavorable Leases [Member]
Goodwill And Intangible Assets [Line Items]
Amortization of intangible assets	$ 330,000	$ 386,000	$ 473,000

Goodwill and Intangible Asset55

Goodwill and Intangible Assets - Summary of Amortization expenses (Detail) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Goodwill And Intangible Assets Disclosure [Abstract]
2,018	$ 14,583
2,019	14,215
2,020	12,517
2,021	12,422
2,022	12,419
Thereafter	23,201
Net carrying Amount	$ 89,357	$ 107,562

Long-term Debt - Schedule of Lo

Long-term Debt - Schedule of Long-term Debt (Detail) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Debt Instrument [Line Items]
Total debt, excluding deferred financing costs	$ 709,470	$ 716,654
Deferred financing costs, net of accumulated amortization	(5,709)	(7,466)
Total debt	703,761	709,188
Current portion of long-term debt and line of credit	7,185	7,185
Long-term debt, net of current portion	696,576	702,003
Term Loan B [Member]
Debt Instrument [Line Items]
Total debt, excluding deferred financing costs	$ 709,470	$ 716,654

Long-term Debt - Schedule of 57

Long-term Debt - Schedule of Long-term Debt (Parenthetical) (Detail)	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
Revolving Credit Facility [Member]
Debt Instrument [Line Items]
Debt instrument maturity date	Mar. 31, 2019	Mar. 31, 2019
Total rate - base plus spread	6.25%	6.00%
Term Loan B [Member]
Debt Instrument [Line Items]
Debt instrument maturity date	Mar. 31, 2021	Mar. 31, 2021
Total rate - base plus spread	4.59%	4.33%

Long-term Debt - Additional Inf

Long-term Debt - Additional Information (Detail) - USD ($)	May 26, 2017	Nov. 10, 2016	Mar. 31, 2015	Mar. 31, 2014	Dec. 31, 2017	Dec. 31, 2016
Debt Instrument [Line Items]
Credit facility expiration period				5 years
Credit facility maximum borrowing capacity				$ 430,000,000
Funds used to pay dividend		$ 271,011,000	$ 140,000,000	173,900,000		$ 169,282,000
Third party debt refinancing expense					$ 1,021,000	3,001,000
Loss on extinguishment of debt					79,000	$ 606,000
Term Loan B [Member]
Debt Instrument [Line Items]
Credit facility maximum borrowing capacity		$ 718,450,000	$ 510,000,000	390,000,000
Decrease in interest rate margin for term loan borrowings	(0.50%)	(0.25%)
Credit facility quarterly principal installment payment					$ 1,796,000
Debt instrument maturity date					Mar. 31, 2021	Mar. 31, 2021
Description of decrease in interest rate margin for term loan borrowings					50 basis points, to LIBOR plus 300 basis points
Decrease in interest rate margin, variable rate for term loan borrowings	(3.00%)
Additional reduction in interest rate margin for term loan borrowings	(0.25%)
Term Loan B [Member] | Maximum [Member]
Debt Instrument [Line Items]
Total net leverage ratio	3.50%
Revolving Credit Facility [Member]
Debt Instrument [Line Items]
Credit facility maximum borrowing capacity		$ 75,000,000		$ 40,000,000
Decrease in interest rate margin for term loan borrowings	(0.25%)
Unused portion of credit facility					$ 75,000,000
Debt instrument maturity date					Mar. 31, 2019	Mar. 31, 2019
Amended Credit Facility [Member]
Debt Instrument [Line Items]
Capitalized and deferred financing costs					$ 257,000	$ 2,219,000
Amended Credit Facility [Member] | Other Expense [Member]
Debt Instrument [Line Items]
Third party debt refinancing expense					1,021,000	3,001,000
Amended Credit Facility [Member] | Interest Expense [Member]
Debt Instrument [Line Items]
Loss on extinguishment of debt					$ 79,000	$ 606,000

Long-term Debt - Schedule of Fu

Long-term Debt - Schedule of Future Annual Payments of Long-term Debt (Detail) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Debt Disclosure [Abstract]
2,018	$ 7,185
2,019	7,185
2,020	7,185
2,021	687,915
Total	$ 709,470	$ 716,654

Derivative Instruments and He60

Derivative Instruments and Hedging Activities - Additional Information (Detail)	12 Months Ended
	Dec. 31, 2017USD ($)	Dec. 31, 2016USD ($)	Dec. 31, 2015USD ($)	Mar. 31, 2017Cap
Derivative Instruments And Hedging Activities Disclosures [Line Items]
Unrealized gain (loss) on interest rate caps, net of tax	$ 1,143,000	$ (78,000)	$ (1,388,000)
LIBOR plus 1.5% [Member]
Derivative Instruments And Hedging Activities Disclosures [Line Items]
Derivative, interest rate cap floor	1.50%
LIBOR Plus 2.5% [Member]
Derivative Instruments And Hedging Activities Disclosures [Line Items]
Derivative, interest rate cap floor	2.50%			2.50%
Interest Rate Cap [Member]
Derivative Instruments And Hedging Activities Disclosures [Line Items]
Number of additional caps | Cap				2
Derivative, inception date	Mar. 31, 2017
Derivative, maturity date	Mar. 31, 2019
Interest rate caps	$ 340,000	306,000
Unrealized gain (loss) on interest rate caps, net of tax	1,143,000	(78,000)	(1,388,000)
Unrealized gain (loss) on interest rate caps, tax	280,000	$ (35,000)	$ (29,000)
Interest Rate Cap [Member] | LIBOR plus 1.5% [Member]
Derivative Instruments And Hedging Activities Disclosures [Line Items]
Derivative, notional amount	134,000,000
Interest Rate Cap [Member] | LIBOR Plus 2.5% [Member]
Derivative Instruments And Hedging Activities Disclosures [Line Items]
Derivative, notional amount	$ 221,633,000

Deferred Revenue - Schedule of

Deferred Revenue - Schedule of Deferred Revenue (Detail) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Deferred Revenue Arrangement [Line Items]
Deferred revenue	$ 27,523	$ 26,131
Deferred revenue, long-term portion	8,440	8,351
Deferred revenue, current portion	19,083	17,780
Prepaid Membership Fees [Member]
Deferred Revenue Arrangement [Line Items]
Deferred revenue	5,198	5,034
Enrollment Fees [Member]
Deferred Revenue Arrangement [Line Items]
Deferred revenue	1,014	1,240
Equipment Discount [Member]
Deferred Revenue Arrangement [Line Items]
Deferred revenue	2,567	2,796
Annual Membership Fees [Member]
Deferred Revenue Arrangement [Line Items]
Deferred revenue	8,113	6,775
Area Development and Franchise Fees [Member]
Deferred Revenue Arrangement [Line Items]
Deferred revenue	$ 10,631	$ 10,286

Deferred Revenue - Additional I

Deferred Revenue - Additional Information (Detail) $ in Thousands	12 Months Ended
	Dec. 31, 2017USD ($)Store	Dec. 31, 2016USD ($)
Deferred Revenue Arrangement [Line Items]
Equipment deposits	$ 6,498	$ 2,170
Deferred revenue expected recognition period		12 months
Equipment Discount [Member]
Deferred Revenue Arrangement [Line Items]
Write-off deferred revenue	$ 107	$ 1,754
Number of franchisee owned- stores | Store	8

Related Party Transactions - Ad

Related Party Transactions - Additional Information (Detail) $ in Thousands	12 Months Ended
	Dec. 31, 2017USD ($)Store	Dec. 31, 2016USD ($)	Dec. 31, 2015USD ($)
Related Party Transaction [Line Items]
Due from related parties, current portion	$ 3,020	$ 2,864
Number of corporate-owned stores utlilizing software | Store	15
Number of franchise stores utlilizing software | Store	300
Board of Directors [Member]
Related Party Transaction [Line Items]
Ownership percentage	10.50%
MMC Fox Run, LLC [Member] | Consulting Agreement [Member]
Related Party Transaction [Line Items]
Rent, lease termination costs and termination fee	$ 898	406	$ 412
Direct TSG Investors [Member]
Related Party Transaction [Line Items]
Payment for management fee	0	0	$ 1,899
Liability payable under tax benefit obligations	44,794	419,071
Direct TSG Investors [Member] | Management Agreement Termination [Member]
Related Party Transaction [Line Items]
Rent, lease termination costs and termination fee		1,000
Area Development Agreements [Member]
Related Party Transaction [Line Items]
Deferred ADA revenue from related parties	$ 389	$ 422

Related Party Transactions - Sc

Related Party Transactions - Schedule of Related Party Transactions (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Related Party Transaction [Line Items]
Total revenue from related parties	$ 5,594	$ 3,098	$ 2,918
Franchise [Member]
Related Party Transaction [Line Items]
Total revenue from related parties	2,130	1,760	1,232
Equipment [Member]
Related Party Transaction [Line Items]
Total revenue from related parties	$ 3,464	$ 1,338	$ 1,686

Stockholder's Equity - Addition

Stockholder's Equity - Additional Information (Detail) - USD ($)	May 10, 2017	Mar. 14, 2017	Dec. 05, 2016	Nov. 22, 2016	Sep. 28, 2016	Jun. 28, 2016	Aug. 11, 2015	Aug. 05, 2015	Jun. 22, 2015	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015	Aug. 06, 2015
Class Of Stock [Line Items]
Convertible stock, conversion description										Following the Merger and the Reclassification, the Company and the Continuing LLC Owners entered into an exchange agreement under which the Continuing LLC Owners (or certain permitted transferees thereof) have the right, from time to time and subject to the terms of the exchange agreement, to exchange their Holdings Units, along with a corresponding number of shares of Class B common stock, for shares of Class A common stock (or cash at the option of the Company) on a one-for-one basis, subject to customary conversion rate adjustments for stock splits, stock dividends, reclassifications and similar transactions.
Proceeds from sale of shares										$ 480,000	$ 136,000
Common stock dividends declared											169,282,000
Dividend equivalent paid to members of Pla-Fit Holdings										$ 1,974,000	$ 101,729,000	$ 140,000,000
Pla-Fit Holdings, LLC [Member]
Class Of Stock [Line Items]
Number of units held by owners	10,869,819	10,209,242		10,136,285	5,406,019	7,891,160				4,762,943	1,271,146
Continuing LLC Owners [Member]
Class Of Stock [Line Items]
Exchanges of Class B common stock, shares										4,762,943	1,271,146
Continuing LLC Owners [Member] | IPO and Secondary Offering [Member]
Class Of Stock [Line Items]
Percentage of economic interest										11.40%
Number of units held by owners										11,192,740
Class A Common Stock [Member]
Class Of Stock [Line Items]
Number of stock issued during period	16,085,510	15,000,000		15,000,000	8,000,000	11,500,000				4,762,943	1,271,146	10,491,000
Common stock, shares outstanding							36,597,985			87,188,000	61,314,000	36,598,000	0
Share price	$ 20.28	$ 20.44		$ 23.22	$ 19.62	$ 16.50
Proceeds from sale of shares	$ 0	$ 0		$ 0	$ 0	$ 0
Exchanges of Class B common stock, shares										25,842,000	24,705,000
Common stock dividends declared										$ 0	$ 169,282,000
Common stock dividends paid, per share											$ 2.78
Common stock dividends declared, date										Nov. 10, 2016
Common stock dividends record, date										Nov. 22, 2016
Common stock dividends paid, date										Dec. 5, 2016
Class A Common Stock [Member] | Pla-Fit Holdings, LLC [Member]
Class Of Stock [Line Items]
Reimbursement of IPO expenses												$ 7,697,000
Class A Common Stock [Member] | Pla-Fit Holdings, LLC [Member] | IPO [Member]
Class Of Stock [Line Items]
Number of stock issued during period							15,525,000
Share price							$ 16
Class A Common Stock [Member] | Direct TSG Investors [Member]
Class Of Stock [Line Items]
Number of shares converted									26,106,930
Number of stock issued during period	5,215,691	4,790,758		4,863,715	2,593,981	3,608,840	5,033,945
Class A Common Stock [Member] | Direct TSG Investors [Member] | IPO and Secondary Offering [Member]
Class Of Stock [Line Items]
Number of stock issued during period										0
Percentage of economic interest										0.00%
Percentage of voting power										0.00%
Class A Common Stock [Member] | Continuing LLC Owners [Member]
Class Of Stock [Line Items]
Number of stock issued during period	10,869,819	10,209,242		10,136,285	5,406,019	7,891,160				4,762,943	1,271,146
Number of shares exchanged										25,842,004	24,704,610
Class A Common Stock [Member] | Continuing LLC Owners [Member] | Pla-Fit Holdings, LLC [Member] | IPO [Member]
Class Of Stock [Line Items]
Number of stock issued during period							10,491,055
Aggregate amount of units issued							$ 156,946,000
Class A Common Stock [Member] | Investor | IPO and Secondary Offering [Member]
Class Of Stock [Line Items]
Number of stock issued during period										87,188,160
Percentage of economic interest										88.60%
Percentage of voting power										88.60%
Class B Common Stock [Member]
Class Of Stock [Line Items]
Common stock, shares outstanding										11,193,000	37,185,000	62,112,000	0
Number of shares exchanged										4,762,943	1,271,146
Class B Common Stock [Member] | Continuing LLC Owners [Member]
Class Of Stock [Line Items]
Number of stock issued during period								72,602,810
Common stock dividend and voting rights description										The shares of Class B common stock have no rights to dividends or distributions, whether in cash or stock, but entitle the holder to one vote per share on matters presented to stockholders of the Company.
Number of shares exchanged	10,869,819	10,209,242		10,136,285	5,406,019	7,891,160				4,762,943	1,271,146
Class B Common Stock [Member] | Continuing LLC Owners [Member] | IPO and Secondary Offering [Member]
Class Of Stock [Line Items]
Percentage of voting power										11.40%
Number of units held by owners										11,192,740
Class B Common Stock [Member] | Continuing LLC Owners [Member] | Pla-Fit Holdings, LLC [Member]
Class Of Stock [Line Items]
Number of stock issued during period								72,602,810
Holdings Units [Member]
Class Of Stock [Line Items]
Common stock dividends paid, per share			$ 2.78
Dividend equivalent paid to members of Pla-Fit Holdings			$ 101,729,000
Accrued dividend equivalents for future payments to holders of unvested share awards										$ 3,899,000
Merger Agreement [Member] | Class A Common Stock [Member] | Direct TSG Investors [Member]
Class Of Stock [Line Items]
Number of shares converted									26,106,930

Equity-Based Compensation - Add

Equity-Based Compensation - Additional Information (Detail) - USD ($) $ / shares in Units, $ in Thousands	1 Months Ended	12 Months Ended
	Aug. 31, 2015	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Share based compensation, compensation expense		$ 152	$ 784
Stock options, expected recognition, weighted-average period		7 months 6 days
Weighted-average grant date fair value of stock options granted		$ 7.73
Selling, general and administrative		$ 60,369	50,008	$ 55,573
Total Unrecognized compensation expense related to unvested stock options.				3,666
Restricted Stock Units [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Share based compensation, weighted-average grant date fair value		$ 23.26
Share based compensation, shares vested		5,167
Selling, general and administrative		$ 184	$ 98
Share based compensation, shares granted		13,498
Weighted-average grant date fair value of restricted stock granted		$ 24.25
Unrecognized compensation expense related to unvested RSUs, including an estimate for pre-vesting forfeitures		$ 219
Stock Options [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Stock options, expected recognition, weighted-average period		1 year 10 months 25 days
Selling, general and administrative		$ 2,195		$ 846
Class M Units [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Share based compensation, shares vested				10.737
Class B Common Stock [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Share based compensation, shares issued			4,238,338
Share based compensation, weighted-average grant date fair value			$ 1.52
Holdings Units [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Share based compensation, compensation expense			$ 337
Share based compensation, shares vested			22,527
Class A Common Stock [Member] | Restricted Stock Units [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Share based compensation, shares granted		13,498
2013 Equity Incentive Plan [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Share based compensation, total unrecognized compensation		$ 53
Stock options, expected recognition, weighted-average period		8 months 12 days
2013 Equity Incentive Plan [Member] | Class M Units [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Share based compensation, vest equally over a period		5 years
Contractual term in years of stock option awards		10 years
2013 Equity Incentive Plan [Member] | Class M Units [Member] | Tranche One [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Award vesting rights, percentage		80.00%
2013 Equity Incentive Plan [Member] | Class M Units [Member] | IPO [Member] | Tranche One [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Award vesting rights, percentage		20.00%
2015 Omnibus Incentive Plan [Member] | Maximum [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Share based compensation, vest equally over a period	10 years
Share based compensation, options granted to employees, directors and officers	7,896,800
2015 Omnibus Incentive Plan [Member] | Minimum [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Share based compensation, vest equally over a period	4 years

Equity-Based Compensation - Sum

Equity-Based Compensation - Summary of Unvested Holdings Unit Activity (Detail) - Unvested Holdings Units [Member] $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2017USD ($)$ / sharesshares
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Units Outstanding at beginning of period | shares	1,025,016
Units forfeited | shares	(150,181)
Units vested | shares	(604,614)
Units Outstanding at end of period | shares	270,221
Weighted average grant date fair value, Outstanding at beginning of period | $ / shares	$ 1.52
Weighted average grant date fair value, Units forfeited | $ / shares	1.52
Weighted average grant date fair value, Units vested | $ / shares	1.52
Weighted average grant date fair value, Outstanding at end of period | $ / shares	$ 1.52
Weighted average remaining contractual term (years), Outstanding at end of period	1 year 4 months 24 days
Aggregate intrinsic value, Outstanding at end of period | $	$ 9,358

Equity-Based Compensation - Fai

Equity-Based Compensation - Fair Value of Stock Option Awards Determined on Grant Date Using Black-Scholes Valuation Model (Detail)	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]
Expected term (years)	6 years 3 months	6 years 3 months
Expected volatility, Minimum		33.20%
Expected volatility, Maximum	32.90%	34.40%
Risk-free interest rate, Minimum	1.86%	1.31%
Risk-free interest rate, Maximum	2.10%	1.76%
Expected volatility	28.60%

Equity-Based Compensation - S69

Equity-Based Compensation - Summary of Stock Option Activity (Detail) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]
Stock Options, Outstanding at beginning of period	404,470
Stock Options, Granted	617,904
Stock Options, Exercised	(27,191)
Stock Options, Forfeited	(76,977)
Stock Options, Outstanding at end of period	918,206
Stock Options, Vested or expected to vest	918,206
Stock Option, Exercisable	90,046
Weighted average exercise price, Outstanding at beginning of period	$ 17.49
Weighted average exercise price, Granted	20.97
Weighted average exercise price, Exercised	17.63
Weighted average exercise price, Forfeited	20.32
Weighted average exercise price, Outstanding at end of period	19.59
Weighted average exercise price, Vested or expected to vest	19.59
Weighted average exercise price, Exercisable	$ 17.23
Weighted average remaining contractual term (years), Outstanding at end of period	8 years 8 months 12 days
Weighted average remaining contractual term (years), Vested or expected to vest	8 years 8 months 12 days
Weighted average remaining contractual term (years), Exercisable	8 years 2 months 12 days
Aggregate intrinsic value, Outstanding		$ 13,811
Aggregate intrinsic value, Vested or expected to vest		13,811
Aggregate intrinsic value, Exercisable		$ 1,567

Equity-Based Compensation - S70

Equity-Based Compensation - Summary of Restricted Stock Units Activity (Detail) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2017USD ($)$ / sharesshares
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Weighted average exercise price, Outstanding at beginning of period	$ 17.49
Restricted Stock Units [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Units Outstanding at beginning of period | shares	7,887
Units granted | shares	13,498
Units vested | shares	(5,167)
Units Outstanding at end of period | shares	16,218
Weighted average exercise price, Outstanding at beginning of period	$ 19.02
Weighted average grant date fair value, Units granted	24.25
Weighted average grant date fair value, Units vested	19.35
Weighted average grant date fair value, Outstanding at end of period	$ 23.26
Weighted average remaining contractual term (years), Outstanding at end of period	7 months 6 days
Aggregate intrinsic value, Outstanding at end of period | $	$ 462

Earnings per share - Additional

Earnings per share - Additional Information (Detail) - shares	5 Months Ended	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2017	Dec. 31, 2016	Aug. 11, 2015	Aug. 06, 2015
Stock Options [Member]
Earnings Per Share Diluted [Line Items]
Anti-dilutive securities excluded from the calculation of earnings per share	108,270	489,133	208,452
Restricted Stock Units [Member]
Earnings Per Share Diluted [Line Items]
Anti-dilutive securities excluded from the calculation of earnings per share	8,160	1,829
Class A Common Stock [Member]
Earnings Per Share Diluted [Line Items]
Common stock, shares outstanding	36,598,000	87,188,000	61,314,000	36,597,985	0
Class B Common Stock [Member]
Earnings Per Share Diluted [Line Items]
Common stock, shares outstanding	62,112,000	11,193,000	37,185,000		0
Class B Common Stock [Member] | Continuing LLC Owners Exchange Agreement
Earnings Per Share Diluted [Line Items]
Anti-dilutive securities excluded from the calculation of earnings per share	62,466,183	19,483,737	55,305,992

Earnings per share - Reconcilia

Earnings per share - Reconciliation of Numerators and Denominators Used to Compute Basic and Diluted Earnings per Share (Detail) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended								5 Months Ended	12 Months Ended
	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2015	Dec. 31, 2017		Dec. 31, 2016		Dec. 31, 2015
Numerator
Net income	$ 829	$ 18,902	$ 18,004	$ 17,866	$ 21,948	$ 14,863	$ 18,091	$ 16,345	$ 23,454	$ 55,601		$ 71,247		$ 38,130
Less: net income attributable to non-controlling interests									19,348	22,455		49,747		19,612
Net income attributable to Planet Fitness, Inc.	$ (3,453)	$ 15,345	$ 12,412	$ 8,842	$ 10,575	$ 3,425	$ 4,132	$ 3,368	$ 4,106	$ 33,146		$ 21,500		$ 18,518
Stock Options [Member]
Effect of dilutive securities:
Weighted-average shares outstanding adjustment										56,198		1,489
Restricted Stock Units [Member]
Effect of dilutive securities:
Weighted-average shares outstanding adjustment										4,962		2,908
Class A Common Stock [Member]
Denominator
Weighted-average shares of Class A common stock outstanding - basic									36,243,557	78,910,390	[1]	43,300,288	[1]	36,244,000	[1]
Effect of dilutive securities:
Weighted-average shares of Class A common stock outstanding - diluted									36,243,557	78,971,550	[1]	43,304,685	[1]	36,244,000	[1]
Earnings per share of Class A common stock - basic	$ (0.04)	$ 0.18	$ 0.16	$ 0.14	$ 0.19	$ 0.08	$ 0.11	$ 0.09	$ 0.11	$ 0.42	[1]	$ 0.50	[1]	$ 0.11	[1]
Earnings per share of Class A common stock - diluted	$ (0.04)	$ 0.18	$ 0.16	$ 0.14	$ 0.18	$ 0.08	$ 0.11	$ 0.09	$ 0.11	$ 0.42	[1]	$ 0.50	[1]	$ 0.11	[1]
[1]	For the year ended December 31, 2015, represents earnings per share of Class A common stock and weighted-average shares of Class A common stock outstanding for the period from August 6, 2015 through December 31, 2015, the period following the recapitalization transactions and IPO (see Note 13).

Income Taxes - Schedule of Inco

Income Taxes - Schedule of Income Before Provision for Income Taxes (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Income Tax Disclosure [Abstract]
Domestic	$ 426,873	$ 88,016	$ 48,716
Foreign	2,308	1,892	(1,438)
Total income before the provision for income taxes	$ 429,181	$ 89,908	$ 47,278

Income Taxes - Schedule of Prov

Income Taxes - Schedule of Provision (Benefit) for Income Taxes Expenses (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Current:
Federal	$ (2,600)	$ 1,206	$ 686
State	2,941	1,428	2,188
Foreign	817	421	139
Total current tax expense	1,158	3,055	3,013
Deferred:
Federal	365,470	11,633	5,636
State	6,857	3,755	935
Foreign	95	218	(436)
Total deferred tax expense	372,422	15,606	6,135
Provision for income taxes	$ 373,580	$ 18,661	$ 9,148

Income Taxes - Additional infor

Income Taxes - Additional information (Detail)	3 Months Ended	12 Months Ended
	Dec. 31, 2017USD ($)	Dec. 31, 2018	Dec. 31, 2017USD ($)Agreementshares	Dec. 31, 2016USD ($)shares	Dec. 31, 2015USD ($)
Tax Credit Carryforward [Line Items]
Corporate tax rate			35.00%	35.00%	35.00%
Tax cuts and jobs act of 2017, change in tax rate, Estimated Additional Income Tax Expense	$ 334,619,000		$ 316,813,000
Tax cuts and jobs act of 2017, change in tax rate, remeasurement of deferred tax assets and liabilities	334,022,000
Tax cuts and jobs act of 2017, change in tax rate, mandatory repatriation	597,000
Current income tax rate			39.50%	39.50%	39.40%
State income tax rate reconciliation noncontrolling interest			2.10%	2.00%	2.50%
Undistributed earnings of foreign operations				$ 0
Unrecognized tax benefits, Current period tax positions			$ 152,000
Unrecognized tax benefits related with acquisition			152,000
Unrecognized tax benefits, Income tax penalties and interest expense			152,000	465,000	$ 0
Portion of unrecognized tax benefit, if recognized would reduce income tax expense	2,608,000		2,608,000
Decrease in next twelve months for unrecognized tax benefits	2,608,000		2,608,000
Liability related to uncertain tax positions	$ 2,608,000		$ 2,608,000	2,608,000
Number of tax receivable agreements | Agreement			2
Applicable tax savings	85.00%		85.00%
Percentage of remaining tax savings			15.00%
Income tax rate maximum tax liability			3.50%
Other income (expense) reflecting change in tax benefit obligation			$ (317,353,000)	2,549,000	$ 72,000
Deferred tax asset	$ 412,091,000		412,091,000	413,581,000
Deferred tax liability	5,938,000		5,938,000	4,412,000
Tax benefit obligation	431,360,000		431,360,000	419,071,000
Continuing LLC Owners [Member]
Tax Credit Carryforward [Line Items]
Decrease in deferred tax assets			(24,371,000)	(25,046,000)
Deferred tax asset	394,108,000		394,108,000	332,471,000
Deferred tax liability	341,089,000		$ 341,089,000	$ 285,730,000
Class A Common Stock [Member] | Continuing LLC Owners [Member]
Tax Credit Carryforward [Line Items]
Number of shares exchanged | shares			25,842,004	24,704,610
US [Member]
Tax Credit Carryforward [Line Items]
Net operating loss carryforwards	2,725,000		$ 2,725,000
Operating loss carryforwards, expiration date			2,037
Valuation allowance recorded	$ 0		$ 0
Scenario Forecast [Member]
Tax Credit Carryforward [Line Items]
Corporate tax rate		21.00%

Income Taxes - Schedule of Reco

Income Taxes - Schedule of Reconciliation of U.S. Statutory Income Tax Rate to Company's Effective Tax Rate (Detail)	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Income Tax Disclosure [Abstract]
U.S. statutory tax rate	35.00%	35.00%	35.00%
State and local taxes, net of federal benefit	1.00%	4.90%	6.20%
State rate change impact on deferred taxes	0.80%	(1.40%)	6.90%
Federal rate change impact on deferred taxes	77.80%
Tax benefit arrangement liability adjustment	(25.80%)		(2.10%)
Foreign tax rate differential		(0.30%)	0.30%
Withholding taxes and other	0.10%		0.20%
Reserve for uncertain tax position	0.10%	3.10%
Income attributable to non-controlling interests	(1.90%)	(20.50%)	(27.10%)
Effective tax rate	87.10%	20.80%	19.40%

Income Taxes - Schedule of Defe

Income Taxes - Schedule of Deferred Tax Assets and Liabilities (Detail) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Deferred tax assets:
Accrued expense and reserves	$ 1,422	$ 865
Deferred revenue	1,900	2,029
Goodwill and intangible assets	404,547	406,447
Net operating loss	603	22
Other	3,619	4,218
Deferred tax assets	412,091	413,581
Deferred tax liabilities:
Prepaid expenses	(773)	(781)
Property and equipment	(5,165)	(3,631)
Total deferred tax liabilities	(5,938)	(4,412)
Total deferred tax assets	406,153	409,169
Reported as:
Deferred income taxes - non-current assets	407,782	410,407
Deferred income taxes - non-current liabilities	(1,629)	(1,238)
Total deferred tax assets	$ 406,153	$ 409,169

Income Taxes - Summary Of Chang

Income Taxes - Summary Of Changes In Unrecognized Tax Positions (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
Income Tax Disclosure [Abstract]
Balance at beginning of year	$ 2,608	$ 300
Increases related to prior year tax positions	0	2,308
Balance at end of year	$ 2,608	$ 2,608

Income Taxes - Schedule of Futu

Income Taxes - Schedule of Future Payments Under Tax Benefit Arrangements (Detail) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Income Tax Disclosure [Abstract]
2,018	$ 31,062
2,019	23,298
2,020	23,596
2,021	24,010
2,022	24,482
Thereafter	304,912
Total	$ 431,360	$ 419,071

Commitments and Contingencies -

Commitments and Contingencies - Additional Information (Detail) - USD ($)	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Commitment And Contingencies [Line Items]
Rental expense	$ 20,296,000	$ 19,203,000	$ 18,186,000
Maximum obligation of guarantees of leases and debt	979,000	1,350,000
Accrued potential obligation recorded under guaranty arrangement	0	$ 0
Advertising Purchase Commitment [Member]
Commitment And Contingencies [Line Items]
Purchase commitments	30,400,000
Equipment Purchase Commitment [Member]
Commitment And Contingencies [Line Items]
Purchase commitments	$ 10,823,000

Commitments and Contingencies81

Commitments and Contingencies - Schedule of Future Commitments Under Noncancelable Operating Leases (Detail) $ in Thousands	Dec. 31, 2017USD ($)
Commitments And Contingencies Disclosure [Abstract]
2,018	$ 14,563
2,019	13,439
2,020	12,495
2,021	10,747
2,022	9,993
Thereafter	48,712
Total	$ 109,949

Retirement Plan - Additional In

Retirement Plan - Additional Information (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Compensation And Retirement Disclosure [Abstract]
Percentage of employer matching contribution	100.00%
Maximum percentage of employee contribution	4.00%
Total employer matching contributions expense	$ 623	$ 484	$ 384

Segments - Additional Informati

Segments - Additional Information (Detail)	3 Months Ended								12 Months Ended
	Dec. 31, 2017USD ($)	Sep. 30, 2017USD ($)	Jun. 30, 2017USD ($)	Mar. 31, 2017USD ($)	Dec. 31, 2016USD ($)	Sep. 30, 2016USD ($)	Jun. 30, 2016USD ($)	Mar. 31, 2016USD ($)	Dec. 31, 2017USD ($)Segment	Dec. 31, 2016USD ($)	Dec. 31, 2015USD ($)
Segment Reporting Information [Line Items]
Number of reportable segments | Segment									3
Number of operating segments | Segment									0
Description of factors used to identify entity's reportable segments									No operating segments aggregated to arrive at the Company’s reportable segments
Revenue	$ 134,028,000	$ 97,496,000	$ 107,316,000	$ 91,102,000	$ 116,419,000	$ 87,007,000	$ 91,472,000	$ 83,343,000	$ 429,942,000	$ 378,241,000	$ 330,537,000
Franchise [Member]
Segment Reporting Information [Line Items]
Revenue									150,155,000	116,488,000	88,085,000
Franchise [Member] | International [Member]
Segment Reporting Information [Line Items]
Revenue									2,368,000	1,771,000	786,000
Franchise [Member] | Placement Services [Member]
Segment Reporting Information [Line Items]
Revenue									11,371,000	10,513,000	9,806,000
Corporate-owned Stores [Member]
Segment Reporting Information [Line Items]
Revenue									112,114,000	104,721,000	98,390,000
Corporate-owned Stores [Member] | International [Member]
Segment Reporting Information [Line Items]
Revenue									4,402,000	4,180,000	$ 2,931,000
Long-lived assets	$ 2,558,000				$ 2,795,000				2,558,000	$ 2,795,000
Intersegment Eliminations [Member]
Segment Reporting Information [Line Items]
Revenue									$ 0

Segments - Summary of Financial

Segments - Summary of Financial Information for the Company's Reportable Segments (Detail) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Segment Reporting Information [Line Items]
Revenue	$ 134,028	$ 97,496	$ 107,316	$ 91,102	$ 116,419	$ 87,007	$ 91,472	$ 83,343	$ 429,942	$ 378,241	$ 330,537
Total Segment EBITDA									496,225	148,535	103,985
Corporate And Other Non Segment [Member]
Segment Reporting Information [Line Items]
Total Segment EBITDA									284,372	(26,007)	(30,051)
Franchise [Member]
Segment Reporting Information [Line Items]
Revenue									150,155	116,488	88,085
Franchise [Member] | Operating Segments [Member]
Segment Reporting Information [Line Items]
Total Segment EBITDA									126,459	97,256	66,030
Franchise [Member] | US [Member]
Segment Reporting Information [Line Items]
Revenue									147,787	114,717	87,299
Franchise [Member] | International [Member]
Segment Reporting Information [Line Items]
Revenue									2,368	1,771	786
Corporate-owned Stores [Member]
Segment Reporting Information [Line Items]
Revenue									112,114	104,721	98,390
Corporate-owned Stores [Member] | Operating Segments [Member]
Segment Reporting Information [Line Items]
Total Segment EBITDA									46,855	40,847	36,070
Corporate-owned Stores [Member] | US [Member]
Segment Reporting Information [Line Items]
Revenue									107,712	100,541	95,459
Corporate-owned Stores [Member] | International [Member]
Segment Reporting Information [Line Items]
Revenue									4,402	4,180	2,931
Equipment [Member]
Segment Reporting Information [Line Items]
Revenue									167,673	157,032	144,062
Equipment [Member] | Operating Segments [Member]
Segment Reporting Information [Line Items]
Total Segment EBITDA									38,539	36,439	31,936
Equipment [Member] | US [Member]
Segment Reporting Information [Line Items]
Revenue									$ 167,673	$ 157,032	$ 144,062

Segments - Reconciliation of To

Segments - Reconciliation of Total Segment EBITDA to Income Before Taxes (Detail) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Segment Reporting [Abstract]
Total Segment EBITDA									$ 496,225	$ 148,535	$ 103,985
Depreciation and amortization									31,761	31,502	32,158
Other income (expense)									316,928	1,371	(275)
Income from operations	$ 42,277	$ 33,954	$ 38,250	$ 33,055	$ 36,068	$ 26,153	$ 27,831	$ 25,610	147,536	115,662	72,102
Interest expense, net									(35,283)	(27,125)	(24,549)
Other income (expense), net									316,928	1,371	(275)
Income before income taxes									$ 429,181	$ 89,908	$ 47,278

Segments - Summary of Company's

Segments - Summary of Company's Assets by Reportable Segment (Detail) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Segment Reporting, Asset Reconciling Item [Line Items]
Total consolidated assets	$ 1,092,465	$ 1,001,442
Operating Segments [Member] | Franchise [Member]
Segment Reporting, Asset Reconciling Item [Line Items]
Total consolidated assets	243,348	202,580
Operating Segments [Member] | Corporate-owned Stores [Member]
Segment Reporting, Asset Reconciling Item [Line Items]
Total consolidated assets	167,367	153,761
Operating Segments [Member] | Equipment [Member]
Segment Reporting, Asset Reconciling Item [Line Items]
Total consolidated assets	206,632	208,809
Unallocated [Member]
Segment Reporting, Asset Reconciling Item [Line Items]
Total consolidated assets	$ 475,118	$ 436,292

Segments - Summary of Company87

Segments - Summary of Company's Goodwill by Reportable Segment (Detail) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Segment Reporting Other Significant Reconciling Item [Line Items]
Goodwill, Net carrying Amount	$ 176,981	$ 176,981
Franchise [Member]
Segment Reporting Other Significant Reconciling Item [Line Items]
Goodwill, Net carrying Amount	16,938	16,938
Corporate-owned Stores [Member]
Segment Reporting Other Significant Reconciling Item [Line Items]
Goodwill, Net carrying Amount	67,377	67,377
Equipment [Member]
Segment Reporting Other Significant Reconciling Item [Line Items]
Goodwill, Net carrying Amount	$ 92,666	$ 92,666

Corporate-owned and Franchise88

Corporate-owned and Franchisee-owned Stores - Schedule of Changes in Corporate-owned and Franchisee-owned Stores (Detail) - Store		12 Months Ended
		Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Franchisor Disclosure [Line Items]
Stores operated at beginning of period		1,313	1,124	918
New stores opened		210	195	209
Stores debranded, sold or consolidated	[1]	(5)	(6)	(3)
Stores operated at end of period		1,518	1,313	1,124
Franchisee-Owned Stores [Member]
Franchisor Disclosure [Line Items]
Stores operated at beginning of period		1,255	1,066	863
New stores opened		206	195	206
Stores debranded, sold or consolidated	[1]	(5)	(6)	(3)
Stores operated at end of period		1,456	1,255	1,066
Corporate-Owned Stores [Member]
Franchisor Disclosure [Line Items]
Stores operated at beginning of period		58	58	55
New stores opened		4		3
Stores operated at end of period		62	58	58
[1]	The term “debrand” refers to a franchisee-owned store whose right to use the Planet Fitness brand and marks has been terminated in accordance with the franchise agreement. We retain the right to prevent debranded stores from continuing to operate as fitness centers. The term “consolidated” refers to the combination of a franchisee’s store with another store located in close proximity with our prior approval. This often coincides with an enlargement, re-equipment and/or refurbishment of the remaining store.

Quarterly Financial Data (Una89

Quarterly Financial Data (Unaudited) - Schedule of Quarterly Financial Data (Detail) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended								5 Months Ended	12 Months Ended
	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2015	Dec. 31, 2017		Dec. 31, 2016		Dec. 31, 2015
Quarterly Financial Information [Line Items]
Total revenue	$ 134,028	$ 97,496	$ 107,316	$ 91,102	$ 116,419	$ 87,007	$ 91,472	$ 83,343		$ 429,942		$ 378,241		$ 330,537
Income from operations	42,277	33,954	38,250	33,055	36,068	26,153	27,831	25,610		147,536		115,662		72,102
Net income	829	18,902	18,004	17,866	21,948	14,863	18,091	16,345	$ 23,454	55,601		71,247		38,130
Net income (loss) attributable to Planet Fitness, Inc.	$ (3,453)	$ 15,345	$ 12,412	$ 8,842	$ 10,575	$ 3,425	$ 4,132	$ 3,368	$ 4,106	$ 33,146		$ 21,500		$ 18,518
Class A Common Stock [Member]
Earnings (loss) per share:
Class A - Basic	$ (0.04)	$ 0.18	$ 0.16	$ 0.14	$ 0.19	$ 0.08	$ 0.11	$ 0.09	$ 0.11	$ 0.42	[1]	$ 0.50	[1]	$ 0.11	[1]
Class A - Diluted	$ (0.04)	$ 0.18	$ 0.16	$ 0.14	$ 0.18	$ 0.08	$ 0.11	$ 0.09	$ 0.11	$ 0.42	[1]	$ 0.50	[1]	$ 0.11	[1]
[1]	For the year ended December 31, 2015, represents earnings per share of Class A common stock and weighted-average shares of Class A common stock outstanding for the period from August 6, 2015 through December 31, 2015, the period following the recapitalization transactions and IPO (see Note 13).

Subsequent events - Additional

Subsequent events - Additional Information (Detail)	Jan. 01, 2018USD ($)Store	Feb. 22, 2018USD ($)	Dec. 31, 2017USD ($)
Subsequent Event [Line Items]
Share repurchase program, authorized amount			$ 20,000,000
Subsequent Event [Member]
Subsequent Event [Line Items]
Asset purchase acquisition, value	$ 28,600,000
Number of franchise stores acquired | Store	6
Acquisition date	Jan. 1, 2018
Share repurchase program, additional authorized amount		$ 80,000,000
Share repurchase program, authorized amount		$ 100,000,000

Valuation and Qualifying Acco91

Valuation and Qualifying Accounts (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Valuation And Qualifying Accounts [Abstract]
Balance at Beginning of Period	$ 687	$ 629	$ 399
Provision for (recovery of) doubtful accounts, net	(19)	58	650
Write-offs and other	(636)		(420)
Balance at End of Period	$ 32	$ 687	$ 629