ProPetro Holding (PUMP) 10-K 1 Mar 19 2018 FY Annual report Financial data

DOCUMENT AND ENTITY INFORMATION

DOCUMENT AND ENTITY INFORMATION - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2018	Feb. 18, 2019	Jun. 30, 2018
Document and Entity Information [Abstract]
Entity Registrant Name	ProPetro Holding Corp.
Entity Central Index Key	1,680,247
Document Type	10-K
Amendment Flag	false
Entity Current Reporting Status	Yes
Entity Filer Category	Large Accelerated Filer
Current Fiscal Year End Date	--12-31
Document Fiscal Year Focus	2,018
Entity Well-known Seasoned Issuer	Yes
Document Period End Date	Dec. 31, 2018
Document Fiscal Period Focus	FY
Entity Common Stock, Shares Outstanding		100,257,626
Entity Voluntary Filers	No
Entity Small Business	false
Entity Emerging Growth Company	false
Entity Shell Company	false
Entity Public Float			$ 838.7

CONSOLIDATED BALANCE SHEETS

CONSOLIDATED BALANCE SHEETS - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
CURRENT ASSETS:
Cash and cash equivalents	$ 132,700	$ 23,949
Accounts receivable - net of allowance for doubtful accounts of $100 and $443, respectively	202,956	199,656
Inventories	6,353	6,184
Prepaid expenses	6,610	5,123
Other current assets	638	748
Total current assets	349,257	235,660
PROPERTY AND EQUIPMENT - Net of accumulated depreciation	912,846	470,910
OTHER NONCURRENT ASSETS:
Goodwill	9,425	9,425
Intangible assets - net of amortization	13	301
Deferred revenue rebate - net of amortization	0	615
Other noncurrent assets	2,981	2,121
Total other noncurrent assets	12,419	12,462
TOTAL ASSETS	1,274,522	719,032
CURRENT LIABILITIES:
Accounts payable	214,460	211,149
Accrued liabilities	138,089	16,607
Current portion of long-term debt	0	15,764
Accrued interest payable	211	76
Total current liabilities	352,760	243,596
DEFERRED INCOME TAXES	54,283	4,881
LONG-TERM DEBT	70,000	57,178
OTHER LONG-TERM LIABILITIES	124	125
Total liabilities	477,167	305,780
COMMITMENTS AND CONTINGENCIES (Note 17)
SHAREHOLDERS’ EQUITY:
Preferred stock, $0.001 par value, 30,000,000 shares authorized, none issued, respectively	0	0
Common stock, $0.001 par value, 200,000,000 shares authorized,100,190,126 and 83,039,854 shares issued, respectively	100	83
Additional paid-in capital	817,690	607,466
Accumulated deficit	(20,435)	(194,297)
Total shareholders’ equity	797,355	413,252
TOTAL LIABILITIES AND SHAREHOLDERS’ EQUITY	$ 1,274,522	$ 719,032

CONSOLIDATED BALANCE SHEETS (Pa

CONSOLIDATED BALANCE SHEETS (Parenthetical) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Statement of Financial Position [Abstract]
Allowance for doubtful accounts	$ 100	$ 443
Preferred stock, par value (in dollars per share)	$ 0.001	$ 0.001
Preferred stock, authorized (in shares)	30,000,000	30,000,000
Preferred stock, issued (in shares)	0	0
Preferred stock, outstanding (in shares)	0	0
Common stock, par value (in dollars per share)	$ 0.001	$ 0.001
Common stock, authorized (in shares)	200,000,000	200,000,000
Common stock, issued (in shares)	100,190,126	83,039,854
Common stock, outstanding (in shares)	100,190,126	83,039,854

CONSOLIDATED STATEMENTS OF OPER

CONSOLIDATED STATEMENTS OF OPERATIONS - USD ($) shares in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
REVENUE - Service revenue	$ 1,704,562,000	$ 981,865,000	$ 436,920,000
COSTS AND EXPENSES:
Cost of services (exclusive of depreciation and amortization)	1,270,577,000	813,823,000	404,140,000
General and administrative (inclusive of stock‑based compensation)	53,958,000	49,215,000	26,613,000
Depreciation and amortization	88,138,000	55,628,000	43,542,000
Property and equipment impairment expense	0	0	6,305,000
Goodwill impairment expense	0	0	1,177,000
Loss on disposal of assets	59,220,000	39,086,000	22,529,000
Total costs and expenses	1,471,893,000	957,752,000	504,306,000
OPERATING INCOME (LOSS)	232,669,000	24,113,000	(67,386,000)
OTHER INCOME (EXPENSE):
Interest expense	(6,889,000)	(7,347,000)	(20,387,000)
Gain on extinguishment of debt	0	0	6,975,000
Other expense	(663,000)	(1,025,000)	(321,000)
Total other income (expense)	(7,552,000)	(8,372,000)	(13,733,000)
INCOME (LOSS) BEFORE INCOME TAXES	225,117,000	15,741,000	(81,119,000)
INCOME TAX (EXPENSE)/BENEFIT	(51,255,000)	(3,128,000)	27,972,000
NET INCOME (LOSS)	$ 173,862,000	$ 12,613,000	$ (53,147,000)
NET INCOME (LOSS) PER COMMON SHARE:
Basic (in dollars per share)	$ 2.08	$ 0.17	$ (1.19)
Diluted (in dollars per share)	$ 2	$ 0.16	$ (1.19)
WEIGHTED AVERAGE COMMON SHARES OUTSTANDING:
Basic (in shares)	83,460	76,371	44,787
Diluted (in shares)	87,046	79,583	44,787
Oil and Gas Service
REVENUE - Service revenue	$ 1,704,562,000	$ 981,865,000	$ 436,920,000

CONSOLIDATED STATEMENTS OF SHAR

CONSOLIDATED STATEMENTS OF SHAREHOLDERS' EQUITY - USD ($) $ in Thousands	Total	Common Stock	Preferred Stock	Preferred Stock	Preferred Additional Paid‑In Capital	Common Stock	Additional Paid‑In Capital	Accumulated Deficit
BALANCE at Dec. 31, 2015	$ 69,571			$ 0	$ 0	$ 35	$ 223,299	$ (153,763)
Balance (in shares) at Dec. 31, 2015				0		34,621,000
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stock‑based compensation cost	1,649						1,649
Stock issued, net of costs		$ 40,425	$ 162,511	$ 17	162,494	$ 18	40,407
Stock issued, net of costs (in shares)				17,000,000		18,007,000
Net income (loss)	(53,147)							(53,147)
BALANCE at Dec. 31, 2016	221,009			$ 17	162,494	$ 53	265,355	(206,910)
Balance (in shares) at Dec. 31, 2016				17,000,000		52,628,000
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stock‑based compensation cost	9,489						9,489
Stock issued, net of costs	170,141					$ 13	170,128
Stock issued, net of costs (in shares)						13,250,000
Conversion of preferred stock to common stock at Initial Public Offering	0			$ (17)	(162,494)	$ 17	162,494
Conversion of preferred stock to common stock at Initial Public Offering (in shares)				(17,000,000)		17,000,000
Issuance of equity award—net	0
Issuance of equity award—net (in shares)						162,000
Net income (loss)	12,613							12,613
BALANCE at Dec. 31, 2017	413,252			$ 0	0	$ 83	607,466	(194,297)
Balance (in shares) at Dec. 31, 2017				0		83,040,000
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stock‑based compensation cost	5,482						5,482
Stock issued, net of costs	204,512					$ 16	204,496
Stock issued, net of costs (in shares)						16,600,000
Exercise of stock options—net	$ 247					$ 1	246
Exercise of stock options—net (in shares)	49,912					550,000
Net income (loss)	$ 173,862							173,862
BALANCE at Dec. 31, 2018	$ 797,355			$ 0	$ 0	$ 100	$ 817,690	$ (20,435)
Balance (in shares) at Dec. 31, 2018				0		100,190,000

CONSOLIDATED STATEMENTS OF CASH

CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($)	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
CASH FLOWS FROM OPERATING ACTIVITIES:
Net income (loss)	$ 173,862,000	$ 12,613,000	$ (53,147,000)
Adjustments to reconcile net income (loss) to net cash provided by operating activities:
Depreciation and amortization	88,138,000	55,628,000	43,542,000
Gain on extinguishment of debt	0	0	(6,975,000)
Property and equipment impairment expense	0	0	6,305,000
Goodwill impairment expense	0	0	1,177,000
Deferred income tax expense (benefit)	49,704,000	3,430,000	(27,972,000)
Amortization of deferred revenue rebate	615,000	1,846,000	1,846,000
Amortization of deferred debt issuance costs	403,000	3,403,000	2,091,000
Stock-based compensation	5,482,000	9,489,000	1,649,000
Loss on disposal of assets	59,220,000	39,086,000	22,529,000
Gain loss on interest rate swap	0	(251,000)	(205,000)
Changes in operating assets and liabilities:
Accounts receivable	(3,300,000)	(84,477,000)	(24,888,000)
Other current assets	207,000	3,304,000	(563,000)
Inventories	(168,000)	(1,472,000)	3,859,000
Prepaid expenses	(1,418,000)	(468,000)	(62,000)
Accounts payable	9,720,000	64,228,000	37,049,000
Accrued liabilities	9,853,000	2,930,000	4,392,000
Accrued interest	761,000	(32,000)	32,000
Net cash provided by operating activities	393,079,000	109,257,000	10,659,000
CASH FLOWS FROM INVESTING ACTIVITIES:
Capital expenditures	(284,197,000)	(285,891,000)	(42,832,000)
Proceeds from sale of assets	3,593,000	4,422,000	1,144,000
Net cash used in investing activities	(280,604,000)	(281,469,000)	(41,688,000)
CASH FLOWS FROM FINANCING ACTIVITIES:
Proceeds from borrowings	77,378,000	60,045,000	0
Repayments of borrowings	(80,946,000)	(166,546,000)	(41,295,000)
Proceeds from insurance financing	5,824,000	4,125,000	4,126,000
Repayments of insurance financing	(4,495,000)	(3,807,000)	(4,527,000)
Extinguishment of debt	0	0	(30,000,000)
Payment of debt extinguishment costs	0	0	(525,000)
Payment of debt issuance costs	(1,732,000)	(1,653,000)	(140,000)
Proceeds from exercise of equity awards	247,000	0	0
Proceeds from additional common equity capitalization	0	0	40,425,000
Proceeds from preferred equity capitalization	0	0	170,000,000
Payment of preferred equity capitalization costs	0	0	(7,489,000)
Proceeds from IPO	0	185,500,000	0
Payment of deferred IPO costs	0	(15,099,000)	(260,000)
Net cash (used in) provided by financing activities	(3,724,000)	62,565,000	130,315,000
NET INCREASE (DECREASE) IN CASH AND CASH EQUIVALENTS	108,751,000	(109,647,000)	99,286,000
CASH AND CASH EQUIVALENTS — Beginning of year	23,949,000	133,596,000	34,310,000
CASH AND CASH EQUIVALENTS — End of year	$ 132,700,000	$ 23,949,000	$ 133,596,000

ORGANIZATION AND HISTORY

ORGANIZATION AND HISTORY	12 Months Ended
	Dec. 31, 2018
Organization, Consolidation and Presentation of Financial Statements [Abstract]
ORGANIZATION AND HISTORY	ORGANIZATION AND HISTORY ProPetro Holding Corp. (“Holding”), a Texas corporation was formed on April 14, 2007, to serve as a holding company for its wholly owned subsidiary ProPetro Services, Inc. (“Services”), a Texas corporation. Services provides hydraulic fracturing (inclusive of acidizing), cementing, coil tubing, drilling and flowback services to oil and gas producers, located primarily in Texas, Oklahoma, New Mexico, Utah, Colorado, and Wyoming. Holding was converted and incorporated to a Delaware Corporation on March 8, 2017. Holding and Services are collectively referred to as the “Company” in the accompanying consolidated financial statements. On December 22, 2016, the Company restated and amended the Company’s Shareholders Agreement and certificate of formation in the state of Texas, approving a reverse stock split, such that each holder of common stock of the Company shall receive one share of common stock for every 170.4667 shares of previous common stock held. In conjunction, the Company amended the amount of authorized shares to 230,000,000 , of which 200,000,000 are common and 30,000,000 are preferred. On March 22, 2017, we consummated our initial public offering (“IPO”) in which 25,000,000 shares of our common stock, par value $0.001 per share, were sold at a public offering price of $14.00 per share, with 13,250,000 shares issued and sold by the Company and 11,750,000 shares sold by existing stockholders. We received net proceeds of approximately $170.1 million after deducting $10.9 million of underwriting discounts and commissions, and $4.5 million of other offering expenses. At closing, we used the proceeds (i) to repay $71.8 million in outstanding borrowings under the term loan, (ii) $86.8 million to fund the purchase of additional hydraulic fracturing units and other equipment, and (iii) the remaining for general corporate purposes. In connection with the IPO, the Company executed a stock split, such that each holder of common stock of the Company received 1.45 shares of common stock for every one share of previous common stock, and all 16,999,990 shares of our outstanding Series A preferred stock converted to common stock on a 1 :1 basis. Accordingly, any information related to or dependent upon the share or option counts in the 2018 , 2017 and 2016 consolidated financial statements and Note 13 Net Income (loss) Per Share , Note 14 Stock‑Based Compensation , Note 18 Equity Capitalization and Note 19 Quarterly Financial Data (Unaudited) have been updated to reflect the effect of the reverse stock split in December 2016 and the stock split in March 2017, as applicable. On December 31, 2018, we consummated the purchase of pressure pumping and related assets of Pioneer and Pioneer Pumping Services. The pressure pumping assets acquired were used to provide integrated well completion services in the Permian Basin to Pioneer’s completion and production operations. The acquisition cost of the assets was comprised of $110.0 million of cash and 16.6 million shares of our common stock. The incremental direct cost of $3.4 million incurred to consummate the transaction was capitalized as part of the acquisition cost. In connection with the acquisition, we became a long-term service provider to Pioneer, providing pressure pumping and related services for a term of up to 10 years. The pressure pumping assets acquired include eight hydraulic fracturing fleets with 510,000 HHP, four coiled tubing units and the associated equipment maintenance facility. We evaluated and determined that the acquisition did not meet the definition of a Business under GAAP because substantially all of the assets acquired are concentrated in a group of similar assets. Accordingly, we have accounted for the acquisition as an asset purchase.

SIGNIFICANT ACCOUNTING POLICIES

SIGNIFICANT ACCOUNTING POLICIES	12 Months Ended
	Dec. 31, 2018
Accounting Policies [Abstract]
SIGNIFICANT ACCOUNTING POLICIES	summary of the significant accounting policies consistently applied in the preparation of the accompanying consolidated financial statements are as follows: Principles of Consolidation — The accompanying consolidated financial statements include the accounts of Holding and its wholly owned subsidiary, Services. All intercompany accounts and transactions have been eliminated in consolidation. Basis of Presentation — The accompanying consolidated financial statements and related notes have been prepared pursuant to the rules and regulations of the Securities Exchange Commission (“SEC”) and in conformity with accounting principles generally accepted in the United States of America (“GAAP”). Use of Estimates — Management is required to make estimates and assumptions that affect the reported amounts of assets and liabilities and the disclosure of contingent assets and liabilities at the date of the consolidated financial statements and revenues and expenses during the reporting period. Such estimates include, but are not limited to, allowance for doubtful accounts, depreciation of property and equipment, estimates of fair value of property and equipment, estimates related to fair value of reporting units for purposes of assessing goodwill, estimates related to deferred tax assets and liabilities, including any related valuation allowances, and estimates of fair value of stock‑based compensation. Actual results could differ from those estimates. Revenue Recognition — The Company’s services are sold based upon contracts with customers. The Company recognizes revenue when it satisfies a performance obligation by transferring control over a product or service to a customer. The following is a description of the principal activities, separated by reportable segment and all other, from which the Company generates its revenue. Pressure Pumping — Pressure pumping consists of downhole pumping services, which includes hydraulic fracturing (inclusive of acidizing services) and cementing. Hydraulic fracturing is a well-stimulation technique intended to optimize hydrocarbon flow paths during the completion phase of shale wellbores. The process involves the injection of water, sand and chemicals under high pressure into shale formations. Hydraulic fracturing contracts with our customer have one performance obligation, which is the contracted total stages, satisfied over time. We recognize revenue over time using a progress output method, unit-of-work performed method, which is based on the agreed fixed transaction price and actual stages completed. We believe that recognizing revenue based on actual stages completed faithfully depicts how our hydraulic fracturing services are transferred to our customers over time. Acidizing, which is part of our hydraulic fracturing operating segment, involves a well-stimulation technique where acid is injected under pressure into formations to form or expand fissures. Acidizing provides downhole solutions, and contracts with customers have one performance obligation, which is satisfied at a point-in-time upon completion of the contracted service when control is transferred to the customer. Jobs for these services are typically short term in nature, with most jobs completed in less than a day. We recognize acidizing revenue at a point-in-time, upon completion of the performance obligation. Our cementing services use pressure pumping equipment to deliver a slurry of liquid cement that is pumped down a well between the casing and the borehole. Cementing involves well bonding solutions, and contracts with customers have one performance obligation, which is satisfied at a point-in-time upon completion of the contracted service when control is transferred to the customer. Jobs for these services are typically short term in nature, with most jobs completed in less than a day. We recognize cementing revenue at a point-in-time, upon completion of the performance obligation. The transaction price for each performance obligation for all our pressure pumping services are fixed per our contract with customer. All Other — All other services consist of our surface drilling, drilling, coil tubing and flowback, which are downhole well stimulation and completion/remedial services. The performance obligation for each of the services has a fixed transaction price which is satisfied at a point-in-time upon completion of the service when control is transferred to the customer. Accordingly, we recognize revenue at a point-in-time, upon completion of the service and transfer of control to the customer. Accounts Receivable — Accounts receivables are stated at the amount billed and billable to customers. Payment is typically due in full upon completion of the job for all of our services to customers. At December 31, 2018 and 2017 accrued revenue (unbilled receivable) included as part of our accounts receivable was $18.0 million and $24.8 million , respectively. At December 31, 2018 , the transaction price allocated to the remaining performance obligation for our partially completed hydraulic fracturing operations was $43.9 million , which is expected to be completed and recognized in one month following the current period balance sheet date, in our pressure pumping reportable segment. At December 31, 2017 the transaction price allocated to the remaining performance obligation for our then partially completed hydraulic fracturing operations was $26.4 million , which was recorded as part of our pressure pumping segment revenue for the year ended December 31, 2018 . At December 31, 2018 , 2017 and 2016 , the allowance for doubtful accounts was $0.1 million , $0.4 million and $0.6 million , respectively. During the year, additional allowance for doubtful accounts was $0.1 million and the allowance no longer required was 0.4 million . Inventories — Inventories, which consists only of raw materials, are stated at lower of average cost and net realizable value. Property and Equipment — The Company’s property and equipment are recorded at cost, less accumulated depreciation. Depreciation — Depreciation of property and equipment is provided on the straight‑line method over the following estimated useful lives: Land Indefinite Buildings and property improvements 5 - 30 years Vehicles 1 ‑ 5 years Equipment 1 ‑ 20 years Leasehold improvements 5 ‑ 20 years Upon sale or retirement of property and equipment, the cost and related accumulated depreciation are removed from the balance sheet and the net amount, less proceeds from disposal, is recognized as a gain or loss in the statement of operations. The Company recorded a loss on disposal of assets of $59.2 million , $39.1 million and $22.5 million for the years ended December 31, 2018 , 2017 and 2016 , respectively. Impairment of Long‑Lived Assets — In accordance with Financial Accounting Standards Board (FASB) Accounting Standards Codification (ASC) 360, Accounting for the Impairment or Disposal of Long‑Lived Assets , the Company reviews its long‑lived assets to be held and used whenever events or circumstances indicate that the carrying value of those assets may not be recoverable. An impairment loss is indicated if the sum of the expected future undiscounted cash flows attributable to the asset group is less than the carrying amount of such asset group. In this circumstance, the Company recognizes an impairment loss for the amount by which the carrying amount of the asset group exceeds the fair value of the asset group. No impairment was recorded in the years ended December 31, 2018 and 2017 . The impairment recorded in 2016 was $6.3 million for property and equipment relating to the drilling asset group. The Company accounts for long‑lived assets to be disposed of at the lower of their carrying amount or fair value, less cost to sell once management has committed to a plan to dispose of the assets. Goodwill — Goodwill is the excess of the consideration transferred over the fair value of the tangible and identifiable intangible assets and liabilities recognized. Goodwill is not amortized. We perform an annual impairment test of goodwill as of December 31, or more frequently if circumstances indicate that impairment may exist. The determination of impairment is made by comparing the carrying amount of a reporting unit with its fair value, which is generally calculated using a combination of market and income approaches. If the fair value of the reporting unit exceeds the carrying value, no further testing is performed. If the fair value of the reporting unit is less than the carrying value, we consider goodwill to be impaired, and the amount of impairment loss is estimated and recorded in the statement of operations. In 2014, we acquired Blackrock Drilling, Inc. (“Blackrock”) for $1.8 million . The assets acquired from Blackrock were recorded as $0.6 million of equipment with the excess of the purchase price over the fair value of the assets recorded as goodwill of $1.2 million . The acquisition complemented our existing drilling operations. The transaction has been accounted for using the acquisition method of accounting and, accordingly, assets and liabilities assumed were recorded at their fair values as of the acquisition date. Based on our goodwill impairment test as of December 31, 2016, the Company concluded that there was an impairment of goodwill of $1.2 million related to the Blackrock acquisition. Accordingly, a $1.2 million impairment expense was recorded during the year ended December 31, 2016, to fully write-down the goodwill related to Blackrock. Prior to the impairment write‑down, the goodwill related to the Blackrock acquisition of $1.2 million was recorded in our all other reportable segment. In 2011, we acquired Technology Stimulation Services, LLC (“TSS”) for $24.4 million . The assets acquired from TSS were recorded as $15.0 million of equipment with the excess of the purchase price over fair value of the assets recorded as goodwill of $9.4 million . The acquisition complemented our existing pressure pumping business. The transaction has been accounted for using the acquisition method of accounting and, accordingly, assets and liabilities assumed were recorded at their fair values as of the acquisition date. Based on our goodwill impairment tests as of December 31, 2018 , 2017 and 2016 , we concluded that the goodwill related to TSS acquisition was not impaired. The goodwill related to the TSS acquisition of $9.4 million is recorded in our pressure pumping reportable segment. Intangible Assets — Intangible assets with finite useful lives are amortized on a basis that reflects the pattern in which the economic benefits of the intangible assets are realized, which is generally on a straight‑line basis over the asset’s estimated useful life. Income Taxes — Income taxes are accounted for under the asset and liability method, which requires the recognition of deferred tax assets and liabilities for the expected future tax consequences of events that have been included in the consolidated financial statements. Under this method, deferred tax assets and liabilities are determined on the basis of differences between the consolidated financial statements and tax bases of assets and liabilities using enacted tax rates in effect for the year in which the differences are expected to reverse. The effect of a change in tax rates on deferred tax assets and liabilities is recognized in income in the period that includes the enactment date. We recognize deferred tax assets to the extent that we believe these assets are more likely than not to be realized. In making such a determination, we consider all positive and negative evidences, including future reversals of existing taxable temporary differences, projected future taxable income, and the results of recent operations. If we determine that we would be able to realize our deferred tax assets in the future in excess of their net recorded amount, we would make an adjustment to the deferred tax asset valuation allowance, which would reduce the provision for income taxes. Advertising Expense — All advertising costs are expensed as incurred. For the years ended December 31, 2018 , 2017 and 2016 , advertising expense was $1.3 million , $0.8 million and $0.4 million , respectively. Deferred Loan Costs — The Company capitalized certain costs in connection with obtaining its borrowings, including lender, legal, and accounting fees. These costs are being amortized over the term of the related loan using the straight‑line method. Deferred loan costs amortization is included in interest expense. Unamortized deferred loan costs associated with loans paid off or refinanced with different lenders are expensed in the period in which such an event occurs. Deferred loan costs are classified as a reduction of long‑term debt or in certain instance as an asset in the consolidated balance sheet. Amortization of deferred loan costs is recorded as interest expense in the statement of operations, and during the years ended December 31, 2018 , 2017 and 2016 , the amount of expense recorded was $0.4 million , $3.4 million and $2.1 million , respectively. Stock-Based Compensation — The Company recognizes the cost of stock‑based awards on a straight‑line basis over the requisite service period of the award, which is usually the vesting period under the fair value method. Total compensation cost is measured on the grant date using fair value estimates. Insurance Financing — The Company annually renews its commercial insurance policies and records a prepaid insurance asset and amortizes it monthly over the coverage period. The Company may choose to finance a portion of the premiums and will make repayments monthly over ten months in equal installments. Concentration of Credit Risk — The Company’s assets that are potentially subject to concentrations of credit risk are cash and cash equivalents and trade accounts receivable. Cash balances are maintained in financial institutions, which at times exceed federally insured limits. The Company monitors the financial condition of the financial institutions in which accounts are maintained and has not experienced any losses in such accounts. The receivables of the Company are spread over a number of customers, a majority of which are credible operators and suppliers to the oil and natural gas industries. The Company performs ongoing credit evaluations as to the financial condition of its customers with respect to trade receivables. Recently Issued Accounting Standards Adopted in 2018 In May 2014, the Financial Accounting Standards Board ("FASB") issued Accounting Standards Update ("ASU") No. 2014-09, Revenue from Contracts with Customers (Topic 606) . ASU No. 2014-09 requires entities to recognize revenue to depict transfer of promised goods or services to customers in an amount that reflects the consideration to which the entity expects to be entitled in exchange for those goods or services. ASU No. 2014-09 requires entities to disclose both qualitative and quantitative information that enables users of the consolidated financial statements to understand the nature, amount, timing, and uncertainty of revenue and cash flows arising from contracts with customers, including disclosure of significant judgments affecting the recognition of revenue. ASU No. 2014-09 was effective for annual periods beginning after December 15, 2017, using either the full retrospective or modified retrospective method. We adopted ASU No. 2014-09 effective January 1, 2018, using the modified retrospective method. The adoption of this guidance had no impact on our prior period results of operations. This is because prior to the effective date of the new revenue guidance, substantially all of our performance obligations per our contracts with customers, except for hydraulic fracturing, were completed at a point-in-time, and revenue recognized when control was transferred to the customers, which is consistent with ASU No. 2014-09. Our hydraulic fracturing segment performance obligation is satisfied over time. Prior to the effective date of the new revenue standards, our hydraulic fracturing segment revenue was recognized based on actual stages completed, i.e. using the output method, which faithfully depicts how our services are transferred over time to our customers and is consistent with the requirements of the new guidance, ASU No. 2014-09. Accordingly, no adjustments to our consolidated financial statements were required, other than the additional disclosures included as part of Note 2 in our consolidated financial statements. Recently Issued Accounting Standards Not Yet Adopted in 2018 In February 2016, the FASB issued ASU No. 2016-02, Leases . This ASU introduces a lessee model that brings most leases on the balance sheet. This new standard increases transparency and comparability by recognizing a lessee’s rights and obligations resulting from leases by recording them on the balance sheet as Right of Use ("ROU") Assets and Lease Liabilities. Leases will be classified as either finance or operating, which will impact the pattern of expense recognition on the income statement. This ASU also requires additional qualitative and quantitative disclosures to better enable users of financial statements to assess the amount, timing, and uncertainty of cash flows arising from leases. This ASU is effective for annual reporting periods beginning after December 15, 2018. Early adoption is permitted. W e adopted this new lease standard effective January 1, 2019 and intend to elect the modified retrospective transition method. As such, the comparative financial information will not be restated and will continue to be reported under the lease standard in effect during those periods. We also intend to elect other practical expedients provided by the new standard, including the package of practical expedients, the short-term lease recognition practical expedient in which leases with a term of 12 months or less will not be recognized on the balance sheet, and the practical expedient to not separate lease and non-lease components for the majority of our leases. We believe that the adoption of this standard will result in an amount no greater than $10.0 million of additional assets and liabilities on our consolidated balance sheet representing the recognition of operating lease right-of-use assets and operating lease liabilities. In January 2017, the FASB issued ASU No. 2017-04, Simplifying the Test for Goodwill Impairment , which removes the requirement to compare the implied fair value of goodwill with its carrying amount as part of step two of the goodwill impairment test. As a result, under this ASU, an entity would recognize an impairment charge for the amount by which the carrying amount exceeds the reporting unit's fair value. Although, the loss recognized should not exceed the total amount of goodwill allocated to that reporting unit. This ASU is effective for impairment tests in fiscal years beginning after December 15, 2019, on a prospective basis. Early adoption is permitted for interim or annual goodwill impairment tests performed on testing dates after January 1, 2017. We believe that the adoption of this guidance will not materially affect our consolidated financial statements.

SUPPLEMENTAL CASH FLOWS INFORMA

SUPPLEMENTAL CASH FLOWS INFORMATION	12 Months Ended
	Dec. 31, 2018
Supplemental Cash Flow Elements [Abstract]
SUPPLEMENTAL CASH FLOWS INFORMATION	SUPPLEMENTAL CASH FLOWS INFORMATION December 31, ($ in thousands) 2018 2017 2016 Supplemental cash flows disclosures Interest paid $ 5,068 $ 3,966 $ 18,249 Income taxes paid $ — $ — $ 3 Supplemental disclosure of non‑cash investing and financing activities Capital expenditures included in accounts payable and accrued liabilities $ 137,647 $ 33,850 $ 3,176 Conversion of preferred stock to common stock at Initial Public Offering $ — $ 162,511 $ — Non-cash purchases of property and equipment $ 204,512 $ — $ —

FAIR VALUE MEASUREMENTS

FAIR VALUE MEASUREMENTS	12 Months Ended
	Dec. 31, 2018
Fair Value Disclosures [Abstract]
FAIR VALUE MEASUREMENTS	FAIR VALUE MEASUREMENTS Fair value is defined as the price that would be received to sell an asset or paid to transfer a liability (i.e., the “exit price”) in an orderly transaction between market participants at the measurement date. In determining fair value, the Company uses various valuation approaches and establishes a hierarchy for inputs used in measuring fair value that maximizes the use of relevant observable inputs and minimizes the use of unobservable inputs by requiring that the most observable inputs be used, when available. Observable inputs are inputs that market participants would use in pricing the asset or liability developed based on market data obtained from sources independent of the Company. Unobservable inputs are inputs that reflect the Company’s assumptions about the assumptions other market participants would use in pricing the asset or liability developed based on the best information available in the circumstances. The hierarchy is broken down into three levels based on the observability of inputs as follows: Level 1 — Valuations based on quoted prices in active markets for identical assets or liabilities that the Company has the ability to access. Valuation adjustments and block discounts are not applied to Level 1 instruments. Since valuations are based on quoted prices that are readily and regularly available in an active market, valuation of these instruments does not entail a significant degree of judgment. Level 2 — Valuations based on one or more quoted prices in markets that are not active or for which all significant inputs are observable, either directly or indirectly. Level 3 — Valuations based on inputs that are unobservable and significant to the overall fair value measurement. A financial instrument’s categorization within the valuation hierarchy is based upon the lowest level of input that is significant to the fair value measurement. The Company’s assessment of the significance of a particular input to the fair value measurement in its entirety requires judgment and considers factors specific to the asset or liability. Assets and Liabilities Measured at Fair Value on a Recurring Basis Our financial instruments include cash and cash equivalents, accounts receivable and accounts payable, accrued liabilities and long-term debt. The estimated fair value of our financial instruments — cash and cash equivalent, accounts receivable and accounts payable and accrued liabilities at December 31, 2018 and 2017 approximates their carrying value as reflected in our consolidated balance sheets because of their short‑term nature. In 2018, we did not have a derivate financial instrument. Prior to 2018, we used a derivative financial instrument, an interest rate swap, to manage interest rate risk. Our policies do not permit the use of derivative financial instruments for speculative purposes. We did not designate the interest rate swap as a hedge for accounting purposes. We record all derivatives as of the end of our reporting period in our consolidated balance sheet at fair value, which is based on quoted market prices, which represents a level 1 in the fair value measurement hierarchy. Based on quoted market prices as of December 31, 2017 and 2016 , for contracts with similar terms and maturity date, as provided by the counterparty, we recorded a gain of $0.3 million and $0.2 million , respectively, in our consolidated statement of operations. The fair value of the interest rate swap liability at December 31, 2017 and 2016 was $0 and $0.3 million , respectively. Assets Measured at Fair Value on a Nonrecurring Basis No assets were measured at fair value on a nonrecurring basis at December 31, 2018 and 2017 , respectively. No impairment was recorded for our property and equipment during the year ended December 31, 2018 and 2017 . In 2016, the depressed cash flows and continued decline in utilization of our drilling assets were indicative of potential impairment, resulting in the Company comparing the carrying value of the drilling assets with its estimated fair value. We determined that the carrying value of the drilling assets was greater than its estimated fair value and accordingly, an impairment expense was recorded. In 2016, the non‑cash asset impairment charges for drilling was $6.3 million , which had a net carrying value of $15.0 million prior to the impairment write‑down. See Note 7, “Impairment of Long‑Lived Assets.” We generally apply fair value techniques to our reporting units on a nonrecurring basis associated with valuing potential impairment loss related to goodwill. Our estimate of the reporting unit fair value is based on a combination of income and market approaches, Level 1 and 3, respectively, in the fair value hierarchy. The income approach involves the use of a discounted cash flow method, with the cash flow projections discounted at an appropriate discount rate. The market approach involves the use of comparable public companies market multiples in estimating the fair value. Significant assumptions include projected revenue growth, capital expenditures, utilization, gross margins, discount rates, terminal growth rates, and weight allocation between income and market approaches. If the reporting unit's carrying amount exceeds its fair value, we consider goodwill impaired, and the impairment loss is recorded in the period. There were no additions to, or disposal of, goodwill during the year ended December 31, 2018 , 2017 and 2016 . Based on our annual goodwill impairment test, no impairment of goodwill was recorded for the year ended December 31, 2018 and 2017 . At December 31, 2016, we estimated the fair value of our surface air drilling reporting unit to be $3.8 million and its carrying value was $4.2 million . As a result of the potential impairment with the carrying value exceeding the estimated fair value, we then further determined the implied fair value of the surface drilling goodwill to be $0 . Accordingly, we recorded an impairment expense of $1.2 million . The impairment expense was attributable to the challenging oil and gas market and slow recovery of crude oil prices, all of which adversely impacted on our expected future cash flows for the surface air drilling reporting unit.

INTANGIBLE ASSETS

INTANGIBLE ASSETS	12 Months Ended
	Dec. 31, 2018
Goodwill and Intangible Assets Disclosure [Abstract]
INTANGIBLE ASSETS	INTANGIBLE ASSETS Intangible assets are composed of internally developed software. Intangible assets are amortized on a straight‑line basis with a useful life of five years. Amortization expense included in net income (loss) for the years ended December 31, 2018 , 2017 and 2016 was $0.3 million , $0.3 million and $0.3 million , respectively. At December 31, 2018 and 2017 , respectively, the company’s intangible assets subject to amortization are as follows: ($ in thousands) 2018 2017 Internally developed software $ 1,440 $ 1,440 Less accumulated amortization 1,427 1,139 Intangible assets — net $ 13 $ 301 Estimated remaining amortization expense for each of the subsequent fiscal years is expected to be as follows: ($ in thousands) Year Estimated 2019 $ 13 2020 — Total $ 13 The average amortization period remaining is approximately 0.05 years .

PROPERTY AND EQUIPMENT

PROPERTY AND EQUIPMENT	12 Months Ended
	Dec. 31, 2018
Property, Plant and Equipment [Abstract]
PROPERTY AND EQUIPMENT	PROPERTY AND EQUIPMENT Property and equipment consisted of the following at December 31, 2018 and 2017 , respectively: ($ in thousands) 2018 2017 Land $ 7,669 $ — Building 23,840 — Equipment and vehicles 1,105,380 646,800 Leasehold improvements 5,559 4,987 Subtotal 1,142,448 651,787 Less accumulated depreciation 229,602 180,877 Property and equipment — net $ 912,846 $ 470,910

IMPAIRMENT OF LONG_LIVED ASSETS

IMPAIRMENT OF LONG‑LIVED ASSETS	12 Months Ended
	Dec. 31, 2018
Impairment of Long-lived Assets [Abstract]
IMPAIRMENT OF LONG‑LIVED ASSETS	IMPAIRMENT OF LONG‑LIVED ASSETS Whenever events or circumstances indicate that the carrying value of long‑lived assets may not be recoverable, the Company reviews the carrying value of long‑lived assets, such as property and equipment and other assets to determine if they are recoverable. If any long‑lived assets are determined to be unrecoverable, an impairment expense is recorded in the period. Asset recoverability is estimated using undiscounted future net cash flows at the lowest identifiable level, excluding interest expense and one‑time other income and expense adjustments. During the year, the Company determined the lowest level of identifiable cash flows to be at the asset group level, which consists of hydraulic fracturing (inclusive of acidizing), cementing, coil tubing, flowback and drilling. During the year ended December 31, 2018 and 2017 , no impairment expense was recorded for any of our asset groups. During the year ended December 31, 2016, the gradual shift from vertical to horizontal drilling rigs in the Permian Basin led to the deterioration in utilization of our drilling rigs, and we expected undiscounted future cash flows to be lower than the carrying value of the drilling assets. Given that the carrying value of the drilling assets may not be recoverable, the Company estimated the fair value of the asset group and compared it to its carrying value. Potential impairment exists if the estimated undiscounted future net cash flows for a given asset group is less than the carrying amount of the asset group. The impairment expense is determined by comparing the estimated fair value with the carrying value of the related asset, and any excess amount by which the carrying value exceeds the fair value is recorded as an impairment expense in the period. At December 31, 2016 , the estimated fair value of the drilling asset group of $8.7 million was determined using the market approach, which represents a level 2 in the fair value measurement hierarchy. Our fair value estimates required us to use significant other observable inputs including assumptions related to replacement cost, among others. Accordingly, an impairment expense of $6.3 million was recorded in 2016 as the carrying value of the drilling asset group of $15.0 million was greater than its then estimated fair value. All other assets group carrying values were determined to be recoverable in 2016.

DEFERRED REVENUE REBATE

DEFERRED REVENUE REBATE	12 Months Ended
	Dec. 31, 2018
Deferred Revenue Disclosure [Abstract]
DEFERRED REVENUE REBATE	DEFERRED REVENUE REBATE In November 2011, the Company acquired certain oilfield fracturing equipment from a customer and agreed to provide future fracturing services to the customer for a period of 78 months in exchange for a 12% $25.0 million note payable to the customer. The Company recorded the fracturing equipment at its estimated fair value of approximately $13.0 million and assigned the remaining value of approximately $12.0 million to a deferred revenue rebate account to be amortized over the customer’s 78 ‑month service period. In March 2013, the Company repaid the note payable to the customer. For each of the years ended December 31, 2018 , 2017 and 2016 the Company recorded $0.6 million , $1.8 million and $1.8 million , respectively, of amortization rebate as a reduction of revenue.

LONG_TERM DEBT

LONG‑TERM DEBT	12 Months Ended
	Dec. 31, 2018
Debt Disclosure [Abstract]
LONG‑TERM DEBT	LONG‑TERM DEBT 2013 Term Loan and Revolving Credit Facility On September 30, 2013, we entered into a term loan in the amount of $220 million ("Term Loan") with a $40 million revolving credit line ("Revolving Credit Facility" ) . Borrowings under the Term Loan and Revolving Credit Facility accrued interest at LIBOR plus 6.25% , subject to a 1% LIBOR floor, and were secured by a first priority lien and security interest in all assets of the Company. The Term Loan and Revolving Credit Facility were scheduled to mature on September 30, 2019 and September 30, 2018, respectively, with quarterly and monthly payments of principal and interest, respectively. Under the Term Loan and Revolving Credit Facility we were required to comply, subject to certain exceptions and materiality qualifiers, with certain customary affirmative and negative covenants, including, but not limited to, covenants pertaining to reporting, insurance, collateral maintenance, change of control, transactions with affiliates, distributions, and limitations on additional indebtedness. In addition, the Term Loan and Revolving Credit Facility included a maximum leverage ratio of 3.5 x EBITDA (earnings before interest, taxes, depreciation, and amortization) to total debt, which became effective March 31, 2014. In 2015, given the then near-term economic uncertainty and volatility of commodity prices, we determined that we were likely to be out of compliance with the leverage ratio covenant under the Term Loan and Revolving Credit Facility at the March 31, 2016 test date. Accordingly, the Company and its then equity sponsor, Energy Capital Partners ("ECP"), commenced negotiations with the lenders to amend the covenants and leverage ratio in the Term Loan and Revolving Credit Facility. The resulting amendment and waiver agreement was executed on June 8, 2016. Under the terms of the amendment, ECP infused $40.0 million of additional equity into the Company, $10.0 million of which was reserved for working capital, with up to $30.0 million available to repurchase debt. A minority shareholder also infused $0.4 million alongside ECP to prevent dilution. The amendment and waiver also suspended the leverage ratio test until June 30, 2017, and provided us with 30 days to deliver any past-due financial statements. Gain on Extinguishment of Debt In connection with the amendment to the Term Loan and Revolving Credit Facility, we initiated an auction process with the lenders to repurchase a portion of debt for a price of $0.80 , a 20% discount to par value. The auction settled on June 16, 2016 as the Company repurchased a total amount of $37.5 million of debt for $30.0 million plus $0.5 million in debt extinguishment auction costs, leading to a gain on extinguishment of debt of $7.0 million . On January 13, 2017, we repaid $75.0 million of the outstanding balance under the Term Loan and repaid the remaining balance of $13.5 million under the Revolving Credit Facility using a portion of the proceeds from our private placement offering. On March 22, 2017, we retired the $71.8 million remaining balance of the Term Loan, along with accrued interest, using a portion of the proceeds from our IPO. Each of the Term Loan and Revolving Credit Facility were terminated in accordance with their terms upon the repayment of outstanding borrowings. Equipment Financing On November 24, 2015, we entered into a 36 months financing arrangement for three hydraulic fracturing units in the amount of $25.0 million , and a portion of the proceeds were used to pay off the previous manufacturer notes, with the remainder being used for additional liquidity. As of December 31, 2018, we have fully repaid all outstanding balance and met all obligations under this financing arrangement. On June 30, 2017, we entered into a financing arrangement for the purchase of light vehicles. As of December 31, 2018 , we have fully repaid all outstanding balance and met all obligations under this financing arrangement. ABL Credit Facility On March 22, 2017, we entered into a new revolving credit facility with a $150.0 million borrowing capacity ("ABL Credit Facility"). Borrowings under the ABL Credit Facility accrue interest based on a three-tier pricing grid tied to availability, and we may elect for loans to be based on either LIBOR or base rate, plus the applicable margin, which ranges from 1.75% to 2.25% for LIBOR loans and 0.75% to 1.25% for base rate loans, with no LIBOR floor. Borrowings under the ABL Credit Facility are secured by a first priority lien and security interest in substantially all assets of the Company. The ABL Credit Facility has a term of 5 years and a borrowing base of 85% of eligible accounts receivable less customary reserves. Under this facility we are required to comply, subject to certain exceptions and materiality qualifiers, with certain customary affirmative and negative covenants, including, but not limited to, covenants pertaining to our ability to incur liens, indebtedness, changes in the nature of our business, mergers and other fundamental changes, disposal of assets, investments and restricted payments, amendments to our organizational documents or accounting policies, prepayments of certain debt, dividends, transactions with affiliates, and certain other activities. In addition, the ABL Credit Facility includes a Springing Fixed Charge Coverage Ratio of 1.0 x when excess availability is less than the greater of (i) 10% of the lesser of the facility size and the Borrowing Base and (ii) $12.0 million . The ABL has a commitment fee of 0.38% , which reduces to 0.25% if utilization is greater than 50% of the borrowing base. On February 22, 2018, we entered into a first amendment with our lenders to increase the capacity of the ABL Credit Facility. The amendment increased total capacity under the facility from $150.0 million to $200.0 million . The first amendment to the ABL Credit Facility modified the Springing Fixed Charge Coverage Ratio to apply when excess availability is less than the greater of (i) 10% of the lesser of the facility size and the Borrowing Base and (ii) $15 million . On December 19, 2018, we entered into a second amendment with our lenders to further increase the capacity of the ABL Credit Facility. The second amendment increased total capacity under the facility from $200.0 million to $300.0 million and extended the maturity date of the ABL Credit Facility from March 22, 2022 until December 19, 2023. The second amendment to the ABL Credit Facility modified the Springing Fixed Charge Coverage Ratio to apply when excess availability is less than the greater of (i) 10% of the lesser of the facility size and the Borrowing Base and (ii) $22.5 million . The fair values of the ABL Credit Facility and equipment financing approximate their carrying values. Total debt consisted of the following notes at December 31, 2018 and 2017 , respectively: ($ in thousands) 2018 2017 ABL Credit Facility $ 70,000 $ 55,000 Equipment financing — 17,942 Total debt 70,000 72,942 Less current portion of long-term debt — 15,764 Total long-term debt $ 70,000 $ 57,178 The loan origination costs relating to the ABL Credit Facility are classified as an asset in the balance sheet. Annual Maturities — Scheduled annual maturities of total debt are as follows at December 31, 2018 : ($ in thousands) 2019 $ — 2020 — 2021 — 2022 — 2023 and thereafter 70,000 Total $ 70,000

ACCRUED LIABILITIES

ACCRUED LIABILITIES	12 Months Ended
	Dec. 31, 2018
Other Liabilities Disclosure [Abstract]
ACCRUED LIABILITIES	ACCRUED LIABILITIES Accrued liabilities consisted of the following at December 31, 2018 and 2017 , respectively: ($ in thousands) 2018 2017 Accrued capital expenditure $ 109,832 $ — Accrued insurance 3,905 2,762 Accrued payroll and related expenses 15,854 10,110 Accrued taxes and others 8,498 3,735 Total $ 138,089 $ 16,607

EMPLOYEE BENEFIT PLAN

EMPLOYEE BENEFIT PLAN	12 Months Ended
	Dec. 31, 2018
Retirement Benefits [Abstract]
EMPLOYEE BENEFIT PLAN	EMPLOYEE BENEFIT PLAN The Company has a 401(k) plan whereby all employees with six months of service may contribute up to $15,000 to the plan annually. The employees vest in the Company contributions to the 401(k) plan 25% per year, beginning in the employee’s second year of service, with full vesting occurring after five years of service. The employees are fully vested in their contributions when made. The Company matches employee contributions 20 cents on the dollar up to 10% of gross salary. During the years ended December 31, 2018 , 2017 and 2016 , the recorded expense under the plan was $0.3 million , $0.2 million and $0.2 million , respectively. Effectively January 1, 2019, we modified our 401(k) plan whereby all employees with sixty days of service may contribute up to $19,000 to the plan annually. The employees vest in the Company contributions to the 401(k) plan 25% per year, beginning in the employee’s first year of service, with full vesting occurring after four years of service. The employees are fully vested in their contributions when made. The Company matches 100% of the employee contributions up to 6% of gross salary.

REPORTABLE SEGMENT INFORMATION

REPORTABLE SEGMENT INFORMATION	12 Months Ended
	Dec. 31, 2018
Segment Reporting [Abstract]
REPORTABLE SEGMENT INFORMATION	REPORTABLE SEGMENT INFORMATION The Company has five operating segments for which discreet financial information is readily available: hydraulic fracturing (inclusive of acidizing), cementing, coil tubing, flowback, and drilling. These operating segments represent how the Chief Operating Decision Maker evaluates performance and allocates resources. On August 31, 2018, we divested our surface air drilling operations, included in our "all other" category, in order to continue to focus and position ourselves as a Permian Basin-focused pressure pumping business because we believe the pressure pumping market in the Permian Basin offers more supportive long-term growth fundamentals. The divestiture of our surface air drilling operations did not qualify for presentation and disclosure as discontinued operations, and accordingly, we have recorded the resulting loss on disposal of our surface air drilling of $0.3 million as part of our loss on disposal of asset in our consolidated statement of operations. The divestiture of our surface air drilling operations resulted in a reduction in the number of our current operating segments to five . The change in the number of our operating segments did not impact our reportable segment information reported for the years ended December 31, 2018 , 2017 and 2016 . In accordance with Accounting Standards Codification 280— Segment Reporting , the Company has one reportable segment (pressure pumping) comprised of the hydraulic fracturing and cementing operating segments. All other operating segments and corporate administrative expenses are included in the ‘‘all other’’ category in the table below. Inter-segment revenues are not material and are not shown separately in the table below. The Company manages and assesses the performance of the reportable segment by its adjusted EBITDA (earnings before other income (expense), interest, taxes, depreciation & amortization, stock-based compensation expense, impairment expense, (gain)/loss on disposal of assets and other unusual or nonrecurring expenses or income). A reconciliation from segment level financial information to the consolidated statement of operations is provided in the table below. ($ in thousands) Pressure All Other Total Year ended and as of December 31, 2018 Service revenue $ 1,658,403 $ 46,159 $ 1,704,562 Adjusted EBITDA $ 398,396 $ (9,873 ) $ 388,523 Depreciation and amortization $ 83,404 $ 4,734 $ 88,138 Capital expenditures $ 577,171 $ 15,431 $ 592,602 Goodwill $ 9,425 $ — $ 9,425 Total assets $ 1,230,830 $ 43,692 $ 1,274,522 Pressure All Other Total Year ended and as of December 31, 2017 Service revenue $ 945,040 $ 36,825 $ 981,865 Adjusted EBITDA $ 145,122 $ (7,679 ) $ 137,443 Depreciation and amortization $ 51,155 $ 4,473 $ 55,628 Capital expenditures $ 300,406 $ 4,893 $ 305,299 Goodwill $ 9,425 $ — $ 9,425 Total assets $ 688,279 $ 30,753 $ 719,032 Pressure All Other Total Year ended and as of December 31, 2016 Service revenue $ 409,014 $ 27,906 $ 436,920 Adjusted EBITDA $ 15,656 $ (7,840 ) $ 7,816 Depreciation and amortization $ 37,282 $ 6,260 $ 43,542 Property and equipment impairment expense $ — $ 6,305 $ 6,305 Goodwill impairment expense $ — $ 1,177 $ 1,177 Capital expenditures $ 45,473 $ 535 $ 46,008 Goodwill $ 9,425 $ — $ 9,425 Total assets $ 501,906 $ 39,516 $ 541,422 Reconciliation of net income (loss) to adjusted EBITDA: ($ in thousands) Pressure All Other Total Year ended December 31, 2018 Net income (loss) $ 253,196 $ (79,334 ) $ 173,862 Depreciation and amortization 83,404 4,734 88,138 Interest expense — 6,889 6,889 Income tax expense — 51,255 51,255 Loss (gain) on disposal of assets 59,962 (742 ) 59,220 Stock‑based compensation — 5,482 5,482 Other expense — 663 663 Other general and administrative expense (1) 2 203 205 Deferred IPO Bonus 1,832 977 2,809 Adjusted EBITDA $ 398,396 $ (9,873 ) $ 388,523 Year ended December 31, 2017 Pressure All Other Total Net income (loss) $ 50,417 $ (37,804 ) $ 12,613 Depreciation and amortization 51,155 4,473 55,628 Interest expense — 7,347 7,347 Income tax expense — 3,128 3,128 Loss on disposal of assets 38,059 1,027 39,086 Stock‑based compensation — 9,489 9,489 Other expense — 1,025 1,025 Other general and administrative expense (1) — 722 722 Deferred IPO Bonus 5,491 2,914 8,405 Adjusted EBITDA $ 145,122 $ (7,679 ) $ 137,443 Pressure All Other Total Year ended December 31, 2016 Net loss $ (45,316 ) $ (7,831 ) $ (53,147 ) Depreciation and amortization 37,282 6,260 43,542 Interest expense — 20,387 20,387 Income tax benefit — (27,972 ) (27,972 ) Loss on disposal of assets 23,690 (1,161 ) 22,529 Property and equipment impairment expense — 6,305 6,305 Goodwill impairment expense — 1,177 1,177 Gain on extinguishment of debt — (6,975 ) (6,975 ) Stock‑based compensation — 1,649 1,649 Other expense — 321 321 Adjusted EBITDA $ 15,656 $ (7,840 ) $ 7,816 (1) Other general and administrative expense relates to legal settlement expense. Major Customers For the years ended December 31, 2018 , 2017 and 2016 , the Company had revenue from the following significant customers that accounted for the following percentages of the Company’s total revenue: 2018 2017 2016 Customer A 24.1 % 15.0 % 18.0 % Customer B 16.5 % 13.8 % 12.5 % Customer C 12.2 % 12.7 % 8.7 % Customer D 8.9 % 12.6 % 7.0 % Customer E 7.1 % 11.8 % — % For the year ended December 31, 2018 , pressure pumping made up 97.4% of Customer A, 98.3% of Customer B, 100.0% of Customer C, 100.0% of Customer D and 100.0% of customer E. For the year ended December 31, 2017 , pressure pumping made up 99.9% of Customer A, 99.2% of Customer B, 99.9% of Customer C, 99.8% of Customer D and 95.5% of customer E. For the year ended December 31, 2016 , pressure pumping made up 96.0% of Customer A, 99.0% of Customer B, 100.0% of Customer C and 99.0% of Customer D.

NET INCOME (LOSS) PER SHARE

NET INCOME (LOSS) PER SHARE	12 Months Ended
	Dec. 31, 2018
Earnings Per Share [Abstract]
NET INCOME (LOSS) PER SHARE	NET INCOME (LOSS) PER SHARE Basic net income (loss) per common share is computed by dividing the net income (loss) relevant to the common stockholders by the weighted-average number of shares outstanding during the year. Diluted net income (loss) per common share uses the same net income (loss) divided by the sum of the weighted-average number of shares of common stock outstanding during the period, plus dilutive effects of options, performance and restricted stocks units outstanding during the period calculated using the treasury method and the potential dilutive effects of preferred stocks (if any) calculated using the if-converted method. The table below shows the calculations for years ended December 31, 2018 , 2017 and 2016 . (In thousands, except for per share data) 2018 2017 2016 Numerator (both basic and diluted) Net income (loss) relevant to common stockholders $ 173,862 $ 12,613 $ (53,147 ) Denominator Denominator for basic income (loss) per share 83,460 76,371 44,787 Dilutive effect of stock options 3,129 2,903 — Dilutive effect of performance stock units 277 59 — Dilutive effect of non-vested restricted stock units 180 250 — Denominator for diluted income (loss) per share 87,046 79,583 44,787 Basic net income (loss) per common share $ 2.08 $ 0.17 $ (1.19 ) Diluted net income (loss) per common share $ 2.00 $ 0.16 $ (1.19 ) As shown in the table below, the following non-vested restricted stock units, preferred stock, performance stock units, and stock options have not been included in the calculation of diluted income (loss) per share for years ended December 31, 2018 , 2017 and 2016 as they would be anti-dilutive to the calculation above. (Count in thousands) 2018 2017 2016 Stock options — — 4,646 Preferred stock — — 17,000 Performance stock units — — — Non-vested restricted stock units — — 372 — — 22,018

STOCK_BASED COMPENSATION

STOCK‑BASED COMPENSATION	12 Months Ended
	Dec. 31, 2018
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
STOCK‑BASED COMPENSATION	STOCK‑BASED COMPENSATION Effective March 4, 2013, we adopted the ProPetro Stock Option Plan pursuant to which our Board of Directors may grant stock options or other stock-based awards to key employees, consultants, and directors. The Plan, as amended, is authorized to grant up to 4,645,884 shares of common stock to be issued upon exercise of the options. The Company’s share price used to estimate the fair value of the option at the grant date was based on a combination of income and market approaches, which are highly complex and sensitive. The income approach involves the use of a discounted cash flow method, with cash flow projections discounted at an appropriate discount rate. The market approach involves the use of comparable public companies market multiples in estimating the fair value of the Company’s stock. The expected term used to calculate the fair value of all options considers the vesting date and the grant’s expiration date. The expected volatility was estimated by considering comparable public companies, and the risk free rate is based on the U.S treasury yield curve as of the grant date. The dividend assumption is based on historical experience. After becoming a public company, the market price was used to determine the market value of our common stock. Prior to 2015, the Company had granted a total of 3,499,228 options with an exercise price of $3.96 per option, and all options expire 10 years from the date of grant. On June 14, 2013, we granted 2,799,408 stock option awards to certain key employees and directors that shall vest and become exercisable based upon the achievement of a service requirement. The options vest in 25% increments for each year of continuous service and an option becomes fully vested upon the optionee’s completion of the fourth year of service. The contractual term for the options awarded is 10 years. The fair value of each option award granted is estimated on the date of grant using the Black-Scholes option-pricing model. The fair value of the options was estimated at the date of grant using the following assumptions: Expected volatility 45 % Expected dividends $ — Expected term (in years) 6.25 Risk free rate 1.35 % On December 1, 2013, we granted 699,820 stock option awards to certain key employees which were scheduled to vest in four substantially equal annual installments, subject to service and performance requirements and acceleration upon a change in control. As of December 31, 2016 and 2015 the performance requirements were not considered to be probable of achievement for any of the outstanding option awards and 114,456 options were forfeited during the year ended December 31, 2016. Effective March 16, 2017, we terminated the options in connection with our IPO and approved a cash bonus totaling $5.1 million to the holders of the options. The contractual term for the options awarded is 10 years. The fair value of each option award granted is estimated on the date of grant using the Black-Scholes option-pricing model. The fair value of the options was estimated at the date of grant using the following assumptions: Expected volatility 45 % Expected dividends $ — Expected term (in years) 6.25 Risk free rate 1.83 % On July 19, 2016, we granted 1,274,549 stock option awards to certain key employees and directors which are scheduled to vest in five substantially equal semi-annual installments commencing in December 2016, subject to a continuing services requirement. The contractual term for the options awarded is 10 years. We fully accelerated vesting of the options in connection with our IPO. The fair value of each option award granted is estimated on the date of grant using the Black- Scholes option-pricing model. The fair value of the options was estimated at the date of grant using the following assumptions: Expected volatility 55 % Expected dividends $ — Expected term (in years) 5.8 Risk free rate 1.22 % In March 2017, our shareholders approved the ProPetro 2017 Incentive Award Plan ("IAP") pursuant to which our Board of Directors may grant stock options, restricted stock units ("RSUs"), performance stock units ("PSUs"), or other stock-based awards to key employees, consultants, directors and employees. The IAP authorizes up to 5,800,000 shares of common stock to be issued under awards granted pursuant to the plan. On March 16, 2017, we granted 793,738 stock option awards to certain key employees and directors pursuant to the IAP which are scheduled to vest in four substantially equal annual installments, subject to a continuing service requirement. The contractual term for the options awarded is 10 years. The fair value of each stock option award granted is estimated on the date of grant using the Black- Scholes option-pricing model. The fair value of the options was estimated at the date of grant using the following assumptions: Expected volatility 18 % Expected dividends $ — Expected term (in years) 6.25 Risk free rate 2.23 % A summary of the stock option activity during the year ended December 31, 2018 is presented below. Number Weighted Outstanding at January 1, 2018 4,636,353 $ 5.20 Granted — — Exercised (49,912 ) $ 4.95 Forfeited (29,255 ) $ 14.00 Expired — $ — Canceled — $ — Outstanding at December 31, 2018 4,557,186 $ 5.14 Exercisable at December 31, 2018 3,994,990 $ 3.90 The weighted average grant-date fair value of stock options granted during the years ended December 31, 2018 , 2017 and 2016 was $0 , $3.35 and $1.77 , respectively. As of December 31, 2018 , the aggregate intrinsic value for our outstanding stock options was $34.0 million , and the aggregate intrinsic value for our exercisable stock options was $34.0 million . The aggregate intrinsic value for the exercised stock options during the year was $0.7 million . The remaining contractual term for the outstanding and exercisable stock options as of December 31, 2018 , were 5.9 years and 5.6 years, respectively. For the years ended December 31, 2018 , 2017 and 2016 , the Company recognized $0.6 million , $2.9 million and $1.6 million , respectively, in compensation expense related to all stock options. Restricted Stock Units (Non-Vested Stock) and Performance Stock Units On September 30, 2013, our Board of Directors authorized and granted 372,335 restricted stock units (RSUs) to a key executive. Each RSU represents the right to receive one share of common stock of the Company at par value $0.001 per share. Under the terms of the award, the shares of common stock subject to the RSUs were to be paid to the grantee upon change in control, regardless of whether the grantee was affiliated with the Company on the settlement date. The fair value of the RSUs is measured as the price of the Company’s shares on the grant date, which was estimated to be $3.89 . The share price used to estimate the fair value of the RSU at the grant date was based on a combination of income and market approaches, which are highly complex and sensitive. The income approach involves the use of a discounted cash flow method, with the cash flow projections discounted at an appropriate discount rate. The market approach involves the use of comparable public companies market multiples in estimating the fair value of the Company’s stock. Effective March 22, 2017, the Board of Directors canceled these RSUs and issued 372,335 new RSUs to the grantee. These issued RSUs are effectively identical to the RSUs granted in 2013, provided, however, that the RSUs was payable in full on March 22, 2018. The fair value of the RSUs issued on March 22, 2017, was based on the Company's closing stock market price at the grant date. In connection with the IPO, we fully recognized the stock compensation expense related to the re-issued RSUs. In 2018, our Board of Directors granted 319,250 RSUs to employees, directors and executives pursuant to the Incentive Award Plan ("IAP"). Each RSU represents the right to receive one share of common stock. The fair value of the RSUs is based on the closing share price of our common stock on the date of grant. For the years ended December 31, 2018 , 2017 and 2016 the recorded stock compensation expense for all RSUs was $2.9 million , $6.2 million and $0 , respectively. As of December 31, 2018 , the total unrecognized compensation expense for all RSUs was approximately $5.7 million , and is expected to be recognized over a weighted-average period of approximately 1.6 years . The following table summarizes the restricted stock units activity during the year December 31, 2018 : Number of Weighted Outstanding at January 1, 2018 688,744 $ 13.66 Granted 319,250 $ 18.49 Vested (500,360 ) $ 13.87 Exercised — $ — Forfeited (34,129 ) $ 15.99 Expired — $ — Canceled — $ — Outstanding at December 31, 2018 473,505 $ 16.52 Effective June 5, 2017, our Board of Directors authorized and granted performance stock unit awards to certain key employees under the IAP. The actual number of shares that may be issued under the performance stock unit awards ranges from zero up to a maximum of twice the target number of performance stock unit awards (“PSUs”) granted to the participant, based on our total shareholder return relative to a designated peer group from the date of our IPO through December 31, 2019. Effective April 18, 2018, our Board of Directors authorized and granted PSUs to certain key employees under the IAP. The actual number of shares that may be issued under the PSUs ranges from zero up to a maximum of twice the target number of performance stock unit awards granted to the participant, based on our total shareholder return relative to a designated peer group from January 1, 2018 through December 31, 2020. Compensation expense is recorded ratably over the corresponding requisite service period. The fair value of performance stock unit awards is determined using a Monte Carlo probability model. Grant recipients do not have any shareholder rights until performance relative to the peer group has been determined following the completion of the performance period and shares have been issued. For the years ended December 31, 2018 , 2017 and 2016 the recorded stock compensation expense for the performance stock units was $2.0 million , $0.4 million and $0 , respectively. The following table summarizes the performance stock units activity during the year ended December 31, 2018 : Period Target Shares Target Target Shares Vested Target Target Shares Weighted 2017 169,635 — — — 169,635 $ 10.73 2018 — 178,975 — — 178,975 $ 27.51 Total 169,635 178,975 — — 348,610 $ 19.34 The total stock compensation expense for the years ended December 31, 2018 , 2017 and 2016 for all stock awards was $5.5 million , $9.5 million and $1.6 million , respectively. The total unrecognized compensation expense as of December 31, 2018 is approximately $11.5 million , and is expected to be recognized over a weighted-average period of approximately 2.0 years .

INCOME TAXES

INCOME TAXES	12 Months Ended
	Dec. 31, 2018
Income Tax Disclosure [Abstract]
INCOME TAXES	INCOME TAXES The components of the provision for income taxes for the years ended December 31, 2018 , 2017 and 2016 are as follows: ($ in thousands) 2018 2017 2016 Federal: Current $ — $ (376 ) $ — Deferred 48,738 3,634 (29,082 ) 48,738 3,258 (29,082 ) State: Current 1,551 74 — Deferred 966 (204 ) 1,110 2,517 (130 ) 1,110 Total expense (benefit) $ 51,255 $ 3,128 $ (27,972 ) Reconciliation between the amounts determined by applying the federal statutory rate of 21% for year ended December 31, 2018 and 35% for the years ended December 31, 2017 and 2016 to income tax (expense)/benefit is as follows: ($ in thousands) 2018 2017 2016 Tax at federal statutory rate $ 47,275 $ 5,510 $ (28,392 ) State taxes, net of federal benefit 1,874 176 (216 ) Non-deductible expenses 2,423 1,582 498 Stock-based compensation (426 ) (655 ) — Valuation allowance (1,151 ) 273 879 Effect of change in enacted Tax Act — (3,448 ) — Other 1,260 (310 ) (741 ) Total expense (benefit) $ 51,255 $ 3,128 $ (27,972 ) Deferred tax assets and liabilities are recognized for estimated future tax effects of temporary differences between the tax basis of an asset or liability and its reported amount in the consolidated financial statements. The significant items giving rise to deferred tax assets (liabilities) at December 31, 2018 and 2017 , respectively, are as follows: ($ in thousands) 2018 2017 Deferred Income Tax Assets Accrued liabilities $ 769 $ 1,264 Allowance for doubtful accounts 21 94 Goodwill and other intangible assets 4,010 5,304 Stock‑based compensation 2,632 2,960 Net operating losses 111,580 56,788 Other 63 69 Noncurrent deferred tax assets 119,075 66,479 Total deferred tax assets 119,075 66,479 Valuation allowance — (1,151 ) Total deferred tax assets — net 119,075 65,328 Deferred Income Tax Liabilities Property and equipment (172,164 ) (68,811 ) Prepaid expenses (1,194 ) (965 ) Other — (131 ) Noncurrent deferred tax liabilities (173,358 ) (69,907 ) Net deferred tax liability $ (54,283 ) $ (4,579 ) At December 31, 2018 , the Company had approximately $516.0 million of federal net operating loss carryforwards that will begin to expire in 2032 and state net operating losses of approximately $50.0 million that will begin to expire in 2024 . Utilization of net operating loss carryforwards may be limited due to past or future ownership changes. As of December 31, 2018, the Company was no longer in a cumulative book loss for the current and two prior years. Based on its estimate of future taxable income, the Company determined it is more likely than not that it will utilize its deferred tax assets. Accordingly, the valuation allowance against its state deferred tax assets was reversed. The Company’s U.S. federal income tax returns for the years ended December 31, 2015 through December 31, 2017 remain open to examination by the Internal Revenue Service under the applicable U.S. federal statute of limitations provisions. The various states in which the Company is subject to income tax are generally open to examination for the tax years ended after December 31, 2014. On December 22, 2017, the U.S. government enacted comprehensive tax legislation commonly referred to as the Tax Cuts and Jobs Act (“Tax Act”). The Tax Act makes broad and complex changes to the U.S. tax code including, but not limited to (1) reducing the U.S. federal corporate tax rate from 35% to 21%, (2) eliminating the corporate alternative minimum tax (“AMT’’) and changing how existing AMT credits can be realized, (3) creating a new limitation on deductible interest expense, (4) changes to bonus depreciation, and (5) changing rules related to use and limitations of net operating loss carryforwards for tax years beginning after December 31, 2017. We have completed our analysis of the Tax Act. The only material items that impacted the Company’s consolidated financial statements in 2017 were bonus depreciation and the corporate rate reduction. While the corporate rate reduction was effective January 1, 2018, we accounted for the effect of the rate change during the year ended December 31, 2017, the year of enactment. Consequently, we recorded a $3.4 million decrease to the net deferred tax liability, with a corresponding net adjustment to deferred tax benefit. In June 2006, the FASB issued FASB Interpretation (FIN) No. 48, Accounting for Uncertainty in Income Taxes — an interpretation of FASB Statement No. 109 (subsequently codified as ASC 740‑10, Income Taxes, Under FASB Statement No. 168, The FASB Accounting Standards Codification and the Hierarchy of Generally Accepted Accounting Principles — a replacement of FASB Statement No. 162 ). ASC 740‑10 prescribes a comprehensive model for recognizing, measuring, presenting, and disclosing in the consolidated financial statements tax positions taken or expected to be taken on a tax return, including a decision to file or not to file in a particular jurisdiction. The Company evaluated all tax positions and determined that the aggregate exposure under ASC 740‑10 did not have a material effect on the consolidated financial statements during the year ended December 31, 2018 , 2017 and 2016 . Therefore, no adjustments have been made to the consolidated financial statements related to the implementation of ASC 740‑10. The Company will continue to evaluate its tax positions in accordance with ASC 740‑10 and will recognize any future effect as a charge to income in the applicable period. Income tax penalties and interest assessments recognized under ASC 740‑10 are accrued as a tax expense in the period that the Company’s taxes are in an uncertain tax position. Any accrued tax penalties or interest assessments will remain until the uncertain tax position is resolved with the taxing authorities or until the applicable statute of limitations has expired.

RELATED_PARTY TRANSACTIONS

RELATED‑PARTY TRANSACTIONS	12 Months Ended
	Dec. 31, 2018
Related Party Transactions [Abstract]
RELATED‑PARTY TRANSACTIONS	RELATED‑PARTY TRANSACTIONS The Company leases its corporate offices from a related party pursuant to a five ‑year lease agreement with a five ‑year extension option requiring a base rent of $0.1 million per year. The Company also leases five properties adjacent to the corporate office from related parties with annual base rents of $0.03 million , $0.03 million , $0.1 million , $0.1 million , and $0.2 million . For the years ended December 31, 2018 , 2017 and 2016 , the Company paid approximately $0.4 million , $0.3 million and $0.2 million , respectively, for the use of transportation services from a related party. The Company also rents equipment in Elk City, Oklahoma from a related party. For the years ended December 31, 2018 , 2017 and 2016 , the Company paid $0.2 million , $0.2 million and $0.2 million , respectively. At December 31, 2018 , 2017 and 2016 , the Company had $0.01 million , $0.02 million and $0 in payables, respectively, and approximately $0 , $0 and $0.04 million in receivables, respectively, for related parties for services provided. All agreements pertaining to realty property and equipment were entered into during periods where the Company had limited liquidity and related parties secured them on behalf of the Company. All related party receivables and payables are immaterial and have not been separately shown on the face of the financial statements.

COMMITMENTS AND CONTINGENCIES

COMMITMENTS AND CONTINGENCIES	12 Months Ended
	Dec. 31, 2018
Commitments and Contingencies Disclosure [Abstract]
COMMITMENTS AND CONTINGENCIES	COMMITMENTS AND CONTINGENCIES Operating Lease — The Company has various operating leases for office space and certain property and equipment. For the years ended December 31, 2018 , 2017 and 2016 , the Company recorded operating lease expense of $1.7 million , $1.4 million and $1.4 million , respectively. Required remaining lease payments for each fiscal year are as follows: ($ in thousands) 2019 $ 892 2020 721 2021 721 2022 721 2023 and thereafter 2,258 Total $ 5,313 Contingent Liabilities — The Company may be subject to various legal actions, claims, and liabilities arising in the ordinary course of business. In the opinion of management, the ultimate disposition of these matters will not have a materially adverse effect on the Company’s financial position, results of operations, or liquidity.

EQUITY CAPITALIZATION

EQUITY CAPITALIZATION	12 Months Ended
	Dec. 31, 2018
Equity [Abstract]
EQUITY CAPITALIZATION	EQUITY CAPITALIZATION Credit Amendment Equity Infusion In connection with the Term Loan and Revolving Credit Facility amendment dated June 8, 2016 (see Note 9), ECP and its related affiliates along with other shareholders infused $40.4 million of equity into the Company and we issued 18,007,328 additional shares of common stock. On November 9, 2017, ECP sold 13,800,000 shares of its common stock holdings in a secondary offering at $15.07 per share, and sold all of their remaining holdings in October of 2018. Convertible Preferred Stock On December 27, 2016, we completed a private placement offering of $170.0 million , issuing 16,999,990 shares of Series A nonparticipating convertible preferred stock, par value $0.001 per share. Costs associated with the offering were approximately $7.0 million , resulting in net proceeds to the Company of approximately $163.0 million . As of December 31, 2016, 16,999,990 shares of Series A convertible preferred stock were issued and outstanding, convertible into common stock at the conversion price per the private placement agreement. In connection with our IPO, all 16,999,990 shares of our outstanding Series A Preferred Stock converted to common stock on a 1 :1 basis. Initial Public Offering On March 22, 2017, we consummated our IPO in which 25,000,000 shares of our common stock, par value $0.001 per share, were sold at a public offering price of $14.00 per share, with 13,250,000 shares issued and sold by the Company and $11,750,000 shares sold by existing stockholders. At December 31, 2018 and 2017 , the Company had 100,190,126 and 83,039,854 shares outstanding, respectively.

QUARTERLY FINANCIAL DATA (UNAUD

QUARTERLY FINANCIAL DATA (UNAUDITED)	12 Months Ended
	Dec. 31, 2018
Quarterly Financial Information Disclosure [Abstract]
QUARTERLY FINANCIAL DATA (UNAUDITED)	QUARTERLY FINANCIAL DATA (UNAUDITED) The following table sets forth our unaudited quarterly results for each of the last four quarters for the years ended December 31, 2018 and 2017 . This unaudited quarterly information has been prepared on the same basis as our annual audited financial statements and includes all adjustments, consisting only of normal recurring adjustments that are necessary to present fairly the financial information for the fiscal quarters presented. 2018 (In thousands, except for per share data) First Quarter Second Quarter Third Quarter Fourth Quarter Service revenue $ 385,219 $ 459,888 $ 434,041 $ 425,414 Gross profit $ 87,097 $ 108,000 $ 113,895 $ 124,993 Net income $ 36,708 $ 39,091 $ 46,285 $ 51,778 Net income per common share: Basic $ 0.44 $ 0.47 $ 0.55 $ 0.62 Diluted $ 0.42 $ 0.45 $ 0.53 $ 0.59 Weighted average common shares outstanding: Basic 83,081 83,447 83,544 83,758 Diluted 86,848 86,878 86,878 87,218 2017 (In thousands, except for per share data) First Quarter Second Quarter Third Quarter Fourth Quarter Service revenue $ 171,931 $ 213,492 $ 282,730 $ 313,712 Gross profit $ 22,366 $ 36,715 $ 57,297 $ 51,664 Net income (loss) $ (24,351 ) $ 4,921 $ 21,965 $ 10,078 Net income (loss) per common share: Basic $ (0.43 ) $ 0.06 $ 0.26 $ 0.12 Diluted $ (0.43 ) $ 0.06 $ 0.25 $ 0.12 Weighted average common shares outstanding: Basic 55,996 83,040 83,040 83,040 Diluted 55,996 86,279 86,264 86,818

SIGNIFICANT ACCOUNTING POLICI_2

SIGNIFICANT ACCOUNTING POLICIES (Policies)	12 Months Ended
	Dec. 31, 2018
Accounting Policies [Abstract]
Principles of Consolidation	Principles of Consolidation — The accompanying consolidated financial statements include the accounts of Holding and its wholly owned subsidiary, Services. All intercompany accounts and transactions have been eliminated in consolidation.
Basis of Presentation	Basis of Presentation — The accompanying consolidated financial statements and related notes have been prepared pursuant to the rules and regulations of the Securities Exchange Commission (“SEC”) and in conformity with accounting principles generally accepted in the United States of America (“GAAP”).
Use of Estimates	Use of Estimates — Management is required to make estimates and assumptions that affect the reported amounts of assets and liabilities and the disclosure of contingent assets and liabilities at the date of the consolidated financial statements and revenues and expenses during the reporting period. Such estimates include, but are not limited to, allowance for doubtful accounts, depreciation of property and equipment, estimates of fair value of property and equipment, estimates related to fair value of reporting units for purposes of assessing goodwill, estimates related to deferred tax assets and liabilities, including any related valuation allowances, and estimates of fair value of stock‑based compensation. Actual results could differ from those estimates.
Revenue Recognition	Revenue Recognition — The Company’s services are sold based upon contracts with customers. The Company recognizes revenue when it satisfies a performance obligation by transferring control over a product or service to a customer. The following is a description of the principal activities, separated by reportable segment and all other, from which the Company generates its revenue.
Accounts Receivable	Accounts Receivable — Accounts receivables are stated at the amount billed and billable to customers. Payment is typically due in full upon completion of the job for all of our services to customers.
Inventories	Inventories — Inventories, which consists only of raw materials, are stated at lower of average cost and net realizable value.
Property and Equipment	Property and Equipment — The Company’s property and equipment are recorded at cost, less accumulated depreciation.
Depreciation	Depreciation — Depreciation of property and equipment is provided on the straight‑line method over the following estimated useful lives: Land Indefinite Buildings and property improvements 5 - 30 years Vehicles 1 ‑ 5 years Equipment 1 ‑ 20 years Leasehold improvements 5 ‑ 20 years
Impairment of Long-Lived Assets	Impairment of Long‑Lived Assets — In accordance with Financial Accounting Standards Board (FASB) Accounting Standards Codification (ASC) 360, Accounting for the Impairment or Disposal of Long‑Lived Assets , the Company reviews its long‑lived assets to be held and used whenever events or circumstances indicate that the carrying value of those assets may not be recoverable. An impairment loss is indicated if the sum of the expected future undiscounted cash flows attributable to the asset group is less than the carrying amount of such asset group. In this circumstance, the Company recognizes an impairment loss for the amount by which the carrying amount of the asset group exceeds the fair value of the asset group. The Company accounts for long‑lived assets to be disposed of at the lower of their carrying amount or fair value, less cost to sell once management has committed to a plan to dispose of the assets.
Goodwill	Goodwill — Goodwill is the excess of the consideration transferred over the fair value of the tangible and identifiable intangible assets and liabilities recognized. Goodwill is not amortized. We perform an annual impairment test of goodwill as of December 31, or more frequently if circumstances indicate that impairment may exist. The determination of impairment is made by comparing the carrying amount of a reporting unit with its fair value, which is generally calculated using a combination of market and income approaches. If the fair value of the reporting unit exceeds the carrying value, no further testing is performed. If the fair value of the reporting unit is less than the carrying value, we consider goodwill to be impaired, and the amount of impairment loss is estimated and recorded in the statement of operations.
Intangible Assets	Intangible Assets — Intangible assets with finite useful lives are amortized on a basis that reflects the pattern in which the economic benefits of the intangible assets are realized, which is generally on a straight‑line basis over the asset’s estimated useful life.
Income Taxes	Income Taxes — Income taxes are accounted for under the asset and liability method, which requires the recognition of deferred tax assets and liabilities for the expected future tax consequences of events that have been included in the consolidated financial statements. Under this method, deferred tax assets and liabilities are determined on the basis of differences between the consolidated financial statements and tax bases of assets and liabilities using enacted tax rates in effect for the year in which the differences are expected to reverse. The effect of a change in tax rates on deferred tax assets and liabilities is recognized in income in the period that includes the enactment date. We recognize deferred tax assets to the extent that we believe these assets are more likely than not to be realized. In making such a determination, we consider all positive and negative evidences, including future reversals of existing taxable temporary differences, projected future taxable income, and the results of recent operations. If we determine that we would be able to realize our deferred tax assets in the future in excess of their net recorded amount, we would make an adjustment to the deferred tax asset valuation allowance, which would reduce the provision for income taxes.
Advertising Expense	Advertising Expense — All advertising costs are expensed as incurred.
Deferred Loan Costs	Deferred Loan Costs — The Company capitalized certain costs in connection with obtaining its borrowings, including lender, legal, and accounting fees. These costs are being amortized over the term of the related loan using the straight‑line method. Deferred loan costs amortization is included in interest expense. Unamortized deferred loan costs associated with loans paid off or refinanced with different lenders are expensed in the period in which such an event occurs. Deferred loan costs are classified as a reduction of long‑term debt or in certain instance as an asset in the consolidated balance sheet. Amortization of deferred loan costs is recorded as interest expense in the statement of operations
Stock Based Compensation	Stock-Based Compensation — The Company recognizes the cost of stock‑based awards on a straight‑line basis over the requisite service period of the award, which is usually the vesting period under the fair value method. Total compensation cost is measured on the grant date using fair value estimates.
Insurance Financing	Insurance Financing — The Company annually renews its commercial insurance policies and records a prepaid insurance asset and amortizes it monthly over the coverage period. The Company may choose to finance a portion of the premiums and will make repayments monthly over ten months in equal installments.
Concentration of Credit Risk	Concentration of Credit Risk — The Company’s assets that are potentially subject to concentrations of credit risk are cash and cash equivalents and trade accounts receivable. Cash balances are maintained in financial institutions, which at times exceed federally insured limits. The Company monitors the financial condition of the financial institutions in which accounts are maintained and has not experienced any losses in such accounts. The receivables of the Company are spread over a number of customers, a majority of which are credible operators and suppliers to the oil and natural gas industries. The Company performs ongoing credit evaluations as to the financial condition of its customers with respect to trade receivables.
Recently Issued Accounting Standards	Recently Issued Accounting Standards Adopted in 2018 In May 2014, the Financial Accounting Standards Board ("FASB") issued Accounting Standards Update ("ASU") No. 2014-09, Revenue from Contracts with Customers (Topic 606) . ASU No. 2014-09 requires entities to recognize revenue to depict transfer of promised goods or services to customers in an amount that reflects the consideration to which the entity expects to be entitled in exchange for those goods or services. ASU No. 2014-09 requires entities to disclose both qualitative and quantitative information that enables users of the consolidated financial statements to understand the nature, amount, timing, and uncertainty of revenue and cash flows arising from contracts with customers, including disclosure of significant judgments affecting the recognition of revenue. ASU No. 2014-09 was effective for annual periods beginning after December 15, 2017, using either the full retrospective or modified retrospective method. We adopted ASU No. 2014-09 effective January 1, 2018, using the modified retrospective method. The adoption of this guidance had no impact on our prior period results of operations. This is because prior to the effective date of the new revenue guidance, substantially all of our performance obligations per our contracts with customers, except for hydraulic fracturing, were completed at a point-in-time, and revenue recognized when control was transferred to the customers, which is consistent with ASU No. 2014-09. Our hydraulic fracturing segment performance obligation is satisfied over time. Prior to the effective date of the new revenue standards, our hydraulic fracturing segment revenue was recognized based on actual stages completed, i.e. using the output method, which faithfully depicts how our services are transferred over time to our customers and is consistent with the requirements of the new guidance, ASU No. 2014-09. Accordingly, no adjustments to our consolidated financial statements were required, other than the additional disclosures included as part of Note 2 in our consolidated financial statements. Recently Issued Accounting Standards Not Yet Adopted in 2018 In February 2016, the FASB issued ASU No. 2016-02, Leases . This ASU introduces a lessee model that brings most leases on the balance sheet. This new standard increases transparency and comparability by recognizing a lessee’s rights and obligations resulting from leases by recording them on the balance sheet as Right of Use ("ROU") Assets and Lease Liabilities. Leases will be classified as either finance or operating, which will impact the pattern of expense recognition on the income statement. This ASU also requires additional qualitative and quantitative disclosures to better enable users of financial statements to assess the amount, timing, and uncertainty of cash flows arising from leases. This ASU is effective for annual reporting periods beginning after December 15, 2018. Early adoption is permitted. W e adopted this new lease standard effective January 1, 2019 and intend to elect the modified retrospective transition method. As such, the comparative financial information will not be restated and will continue to be reported under the lease standard in effect during those periods. We also intend to elect other practical expedients provided by the new standard, including the package of practical expedients, the short-term lease recognition practical expedient in which leases with a term of 12 months or less will not be recognized on the balance sheet, and the practical expedient to not separate lease and non-lease components for the majority of our leases. We believe that the adoption of this standard will result in an amount no greater than $10.0 million of additional assets and liabilities on our consolidated balance sheet representing the recognition of operating lease right-of-use assets and operating lease liabilities. In January 2017, the FASB issued ASU No. 2017-04, Simplifying the Test for Goodwill Impairment , which removes the requirement to compare the implied fair value of goodwill with its carrying amount as part of step two of the goodwill impairment test. As a result, under this ASU, an entity would recognize an impairment charge for the amount by which the carrying amount exceeds the reporting unit's fair value. Although, the loss recognized should not exceed the total amount of goodwill allocated to that reporting unit. This ASU is effective for impairment tests in fiscal years beginning after December 15, 2019, on a prospective basis. Early adoption is permitted for interim or annual goodwill impairment tests performed on testing dates after January 1, 2017. We believe that the adoption of this guidance will not materially affect our consolidated financial statements.
Fair Value Measurements	FAIR VALUE MEASUREMENTS Fair value is defined as the price that would be received to sell an asset or paid to transfer a liability (i.e., the “exit price”) in an orderly transaction between market participants at the measurement date. In determining fair value, the Company uses various valuation approaches and establishes a hierarchy for inputs used in measuring fair value that maximizes the use of relevant observable inputs and minimizes the use of unobservable inputs by requiring that the most observable inputs be used, when available. Observable inputs are inputs that market participants would use in pricing the asset or liability developed based on market data obtained from sources independent of the Company. Unobservable inputs are inputs that reflect the Company’s assumptions about the assumptions other market participants would use in pricing the asset or liability developed based on the best information available in the circumstances. The hierarchy is broken down into three levels based on the observability of inputs as follows: Level 1 — Valuations based on quoted prices in active markets for identical assets or liabilities that the Company has the ability to access. Valuation adjustments and block discounts are not applied to Level 1 instruments. Since valuations are based on quoted prices that are readily and regularly available in an active market, valuation of these instruments does not entail a significant degree of judgment. Level 2 — Valuations based on one or more quoted prices in markets that are not active or for which all significant inputs are observable, either directly or indirectly. Level 3 — Valuations based on inputs that are unobservable and significant to the overall fair value measurement. A financial instrument’s categorization within the valuation hierarchy is based upon the lowest level of input that is significant to the fair value measurement. The Company’s assessment of the significance of a particular input to the fair value measurement in its entirety requires judgment and considers factors specific to the asset or liability.

SIGNIFICANT ACCOUNTING POLICI_3

SIGNIFICANT ACCOUNTING POLICIES (Tables)	12 Months Ended
	Dec. 31, 2018
Accounting Policies [Abstract]
Property and equipment	Depreciation of property and equipment is provided on the straight‑line method over the following estimated useful lives: Land Indefinite Buildings and property improvements 5 - 30 years Vehicles 1 ‑ 5 years Equipment 1 ‑ 20 years Leasehold improvements 5 ‑ 20 years Property and equipment consisted of the following at December 31, 2018 and 2017 , respectively: ($ in thousands) 2018 2017 Land $ 7,669 $ — Building 23,840 — Equipment and vehicles 1,105,380 646,800 Leasehold improvements 5,559 4,987 Subtotal 1,142,448 651,787 Less accumulated depreciation 229,602 180,877 Property and equipment — net $ 912,846 $ 470,910

SUPPLEMENTAL CASH FLOWS INFOR_2

SUPPLEMENTAL CASH FLOWS INFORMATION (Tables)	12 Months Ended
	Dec. 31, 2018
Supplemental Cash Flow Elements [Abstract]
Supplemental cash flow disclosures	December 31, ($ in thousands) 2018 2017 2016 Supplemental cash flows disclosures Interest paid $ 5,068 $ 3,966 $ 18,249 Income taxes paid $ — $ — $ 3 Supplemental disclosure of non‑cash investing and financing activities Capital expenditures included in accounts payable and accrued liabilities $ 137,647 $ 33,850 $ 3,176 Conversion of preferred stock to common stock at Initial Public Offering $ — $ 162,511 $ — Non-cash purchases of property and equipment $ 204,512 $ — $ —

FAIR VALUE MEASUREMENTS (Tables

FAIR VALUE MEASUREMENTS (Tables)	12 Months Ended
	Dec. 31, 2018
Fair Value Disclosures [Abstract]
Assets measured at fair value on a nonrecurring basis	No assets were measured at fair value on a nonrecurring basis at December 31, 2018 and 2017 , respectively.

INTANGIBLE ASSETS (Tables)

INTANGIBLE ASSETS (Tables)	12 Months Ended
	Dec. 31, 2018
Goodwill and Intangible Assets Disclosure [Abstract]
Intangible assets subject to amortization	At December 31, 2018 and 2017 , respectively, the company’s intangible assets subject to amortization are as follows: ($ in thousands) 2018 2017 Internally developed software $ 1,440 $ 1,440 Less accumulated amortization 1,427 1,139 Intangible assets — net $ 13 $ 301
Estimated remaining amortization expense	Estimated remaining amortization expense for each of the subsequent fiscal years is expected to be as follows: ($ in thousands) Year Estimated 2019 $ 13 2020 — Total $ 13

PROPERTY AND EQUIPMENT (Tables)

PROPERTY AND EQUIPMENT (Tables)	12 Months Ended
	Dec. 31, 2018
Property, Plant and Equipment [Abstract]
Property and equipment	Depreciation of property and equipment is provided on the straight‑line method over the following estimated useful lives: Land Indefinite Buildings and property improvements 5 - 30 years Vehicles 1 ‑ 5 years Equipment 1 ‑ 20 years Leasehold improvements 5 ‑ 20 years Property and equipment consisted of the following at December 31, 2018 and 2017 , respectively: ($ in thousands) 2018 2017 Land $ 7,669 $ — Building 23,840 — Equipment and vehicles 1,105,380 646,800 Leasehold improvements 5,559 4,987 Subtotal 1,142,448 651,787 Less accumulated depreciation 229,602 180,877 Property and equipment — net $ 912,846 $ 470,910

LONG_TERM DEBT (Tables)

LONG‑TERM DEBT (Tables)	12 Months Ended
	Dec. 31, 2018
Debt Disclosure [Abstract]
Schedule of debt	Total debt consisted of the following notes at December 31, 2018 and 2017 , respectively: ($ in thousands) 2018 2017 ABL Credit Facility $ 70,000 $ 55,000 Equipment financing — 17,942 Total debt 70,000 72,942 Less current portion of long-term debt — 15,764 Total long-term debt $ 70,000 $ 57,178
Annual maturities of debt	Scheduled annual maturities of total debt are as follows at December 31, 2018 : ($ in thousands) 2019 $ — 2020 — 2021 — 2022 — 2023 and thereafter 70,000 Total $ 70,000

ACCRUED LIABILITIES (Tables)

ACCRUED LIABILITIES (Tables)	12 Months Ended
	Dec. 31, 2018
Other Liabilities Disclosure [Abstract]
Accrued liabilities	Accrued liabilities consisted of the following at December 31, 2018 and 2017 , respectively: ($ in thousands) 2018 2017 Accrued capital expenditure $ 109,832 $ — Accrued insurance 3,905 2,762 Accrued payroll and related expenses 15,854 10,110 Accrued taxes and others 8,498 3,735 Total $ 138,089 $ 16,607

REPORTABLE SEGMENT INFORMATION

REPORTABLE SEGMENT INFORMATION (Tables)	12 Months Ended
	Dec. 31, 2018
Segment Reporting [Abstract]
Reconciliation of segment information	A reconciliation from segment level financial information to the consolidated statement of operations is provided in the table below. ($ in thousands) Pressure All Other Total Year ended and as of December 31, 2018 Service revenue $ 1,658,403 $ 46,159 $ 1,704,562 Adjusted EBITDA $ 398,396 $ (9,873 ) $ 388,523 Depreciation and amortization $ 83,404 $ 4,734 $ 88,138 Capital expenditures $ 577,171 $ 15,431 $ 592,602 Goodwill $ 9,425 $ — $ 9,425 Total assets $ 1,230,830 $ 43,692 $ 1,274,522 Pressure All Other Total Year ended and as of December 31, 2017 Service revenue $ 945,040 $ 36,825 $ 981,865 Adjusted EBITDA $ 145,122 $ (7,679 ) $ 137,443 Depreciation and amortization $ 51,155 $ 4,473 $ 55,628 Capital expenditures $ 300,406 $ 4,893 $ 305,299 Goodwill $ 9,425 $ — $ 9,425 Total assets $ 688,279 $ 30,753 $ 719,032 Pressure All Other Total Year ended and as of December 31, 2016 Service revenue $ 409,014 $ 27,906 $ 436,920 Adjusted EBITDA $ 15,656 $ (7,840 ) $ 7,816 Depreciation and amortization $ 37,282 $ 6,260 $ 43,542 Property and equipment impairment expense $ — $ 6,305 $ 6,305 Goodwill impairment expense $ — $ 1,177 $ 1,177 Capital expenditures $ 45,473 $ 535 $ 46,008 Goodwill $ 9,425 $ — $ 9,425 Total assets $ 501,906 $ 39,516 $ 541,422 Reconciliation of net income (loss) to adjusted EBITDA: ($ in thousands) Pressure All Other Total Year ended December 31, 2018 Net income (loss) $ 253,196 $ (79,334 ) $ 173,862 Depreciation and amortization 83,404 4,734 88,138 Interest expense — 6,889 6,889 Income tax expense — 51,255 51,255 Loss (gain) on disposal of assets 59,962 (742 ) 59,220 Stock‑based compensation — 5,482 5,482 Other expense — 663 663 Other general and administrative expense (1) 2 203 205 Deferred IPO Bonus 1,832 977 2,809 Adjusted EBITDA $ 398,396 $ (9,873 ) $ 388,523 Year ended December 31, 2017 Pressure All Other Total Net income (loss) $ 50,417 $ (37,804 ) $ 12,613 Depreciation and amortization 51,155 4,473 55,628 Interest expense — 7,347 7,347 Income tax expense — 3,128 3,128 Loss on disposal of assets 38,059 1,027 39,086 Stock‑based compensation — 9,489 9,489 Other expense — 1,025 1,025 Other general and administrative expense (1) — 722 722 Deferred IPO Bonus 5,491 2,914 8,405 Adjusted EBITDA $ 145,122 $ (7,679 ) $ 137,443 Pressure All Other Total Year ended December 31, 2016 Net loss $ (45,316 ) $ (7,831 ) $ (53,147 ) Depreciation and amortization 37,282 6,260 43,542 Interest expense — 20,387 20,387 Income tax benefit — (27,972 ) (27,972 ) Loss on disposal of assets 23,690 (1,161 ) 22,529 Property and equipment impairment expense — 6,305 6,305 Goodwill impairment expense — 1,177 1,177 Gain on extinguishment of debt — (6,975 ) (6,975 ) Stock‑based compensation — 1,649 1,649 Other expense — 321 321 Adjusted EBITDA $ 15,656 $ (7,840 ) $ 7,816 (1) Other general and administrative expense relates to legal settlement expense.
Major customers	For the years ended December 31, 2018 , 2017 and 2016 , the Company had revenue from the following significant customers that accounted for the following percentages of the Company’s total revenue: 2018 2017 2016 Customer A 24.1 % 15.0 % 18.0 % Customer B 16.5 % 13.8 % 12.5 % Customer C 12.2 % 12.7 % 8.7 % Customer D 8.9 % 12.6 % 7.0 % Customer E 7.1 % 11.8 % — %

NET INCOME (LOSS) PER SHARE (Ta

NET INCOME (LOSS) PER SHARE (Tables)	12 Months Ended
	Dec. 31, 2018
Earnings Per Share [Abstract]
Calculations of net income (loss) per share	The table below shows the calculations for years ended December 31, 2018 , 2017 and 2016 . (In thousands, except for per share data) 2018 2017 2016 Numerator (both basic and diluted) Net income (loss) relevant to common stockholders $ 173,862 $ 12,613 $ (53,147 ) Denominator Denominator for basic income (loss) per share 83,460 76,371 44,787 Dilutive effect of stock options 3,129 2,903 — Dilutive effect of performance stock units 277 59 — Dilutive effect of non-vested restricted stock units 180 250 — Denominator for diluted income (loss) per share 87,046 79,583 44,787 Basic net income (loss) per common share $ 2.08 $ 0.17 $ (1.19 ) Diluted net income (loss) per common share $ 2.00 $ 0.16 $ (1.19 )
Anti-dilutive shares excluded from diluted earnings (loss) per share calculation	As shown in the table below, the following non-vested restricted stock units, preferred stock, performance stock units, and stock options have not been included in the calculation of diluted income (loss) per share for years ended December 31, 2018 , 2017 and 2016 as they would be anti-dilutive to the calculation above. (Count in thousands) 2018 2017 2016 Stock options — — 4,646 Preferred stock — — 17,000 Performance stock units — — — Non-vested restricted stock units — — 372 — — 22,018

STOCK_BASED COMPENSATION (Table

STOCK‑BASED COMPENSATION (Tables)	12 Months Ended
	Dec. 31, 2018
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Stock options, valuation assumptions	The fair value of each stock option award granted is estimated on the date of grant using the Black- Scholes option-pricing model. The fair value of the options was estimated at the date of grant using the following assumptions: Expected volatility 18 % Expected dividends $ — Expected term (in years) 6.25 Risk free rate 2.23 % The fair value of the options was estimated at the date of grant using the following assumptions: Expected volatility 45 % Expected dividends $ — Expected term (in years) 6.25 Risk free rate 1.83 % The fair value of each option award granted is estimated on the date of grant using the Black- Scholes option-pricing model. The fair value of the options was estimated at the date of grant using the following assumptions: Expected volatility 55 % Expected dividends $ — Expected term (in years) 5.8 Risk free rate 1.22 % The fair value of the options was estimated at the date of grant using the following assumptions: Expected volatility 45 % Expected dividends $ — Expected term (in years) 6.25 Risk free rate 1.35 %
Schedule of stock options, activity	A summary of the stock option activity during the year ended December 31, 2018 is presented below. Number Weighted Outstanding at January 1, 2018 4,636,353 $ 5.20 Granted — — Exercised (49,912 ) $ 4.95 Forfeited (29,255 ) $ 14.00 Expired — $ — Canceled — $ — Outstanding at December 31, 2018 4,557,186 $ 5.14 Exercisable at December 31, 2018 3,994,990 $ 3.90
Schedule of RSUs, activity	The following table summarizes the restricted stock units activity during the year December 31, 2018 : Number of Weighted Outstanding at January 1, 2018 688,744 $ 13.66 Granted 319,250 $ 18.49 Vested (500,360 ) $ 13.87 Exercised — $ — Forfeited (34,129 ) $ 15.99 Expired — $ — Canceled — $ — Outstanding at December 31, 2018 473,505 $ 16.52
Schedule of performance shares, activity	The following table summarizes the performance stock units activity during the year ended December 31, 2018 : Period Target Shares Target Target Shares Vested Target Target Shares Weighted 2017 169,635 — — — 169,635 $ 10.73 2018 — 178,975 — — 178,975 $ 27.51 Total 169,635 178,975 — — 348,610 $ 19.34

INCOME TAXES (Tables)

INCOME TAXES (Tables)	12 Months Ended
	Dec. 31, 2018
Income Tax Disclosure [Abstract]
Schedule of components of income tax expense (benefit)	The components of the provision for income taxes for the years ended December 31, 2018 , 2017 and 2016 are as follows: ($ in thousands) 2018 2017 2016 Federal: Current $ — $ (376 ) $ — Deferred 48,738 3,634 (29,082 ) 48,738 3,258 (29,082 ) State: Current 1,551 74 — Deferred 966 (204 ) 1,110 2,517 (130 ) 1,110 Total expense (benefit) $ 51,255 $ 3,128 $ (27,972 )
Schedule of effective income tax rate reconciliation	Reconciliation between the amounts determined by applying the federal statutory rate of 21% for year ended December 31, 2018 and 35% for the years ended December 31, 2017 and 2016 to income tax (expense)/benefit is as follows: ($ in thousands) 2018 2017 2016 Tax at federal statutory rate $ 47,275 $ 5,510 $ (28,392 ) State taxes, net of federal benefit 1,874 176 (216 ) Non-deductible expenses 2,423 1,582 498 Stock-based compensation (426 ) (655 ) — Valuation allowance (1,151 ) 273 879 Effect of change in enacted Tax Act — (3,448 ) — Other 1,260 (310 ) (741 ) Total expense (benefit) $ 51,255 $ 3,128 $ (27,972 )
Schedule of deferred tax assets and liabilities	The significant items giving rise to deferred tax assets (liabilities) at December 31, 2018 and 2017 , respectively, are as follows: ($ in thousands) 2018 2017 Deferred Income Tax Assets Accrued liabilities $ 769 $ 1,264 Allowance for doubtful accounts 21 94 Goodwill and other intangible assets 4,010 5,304 Stock‑based compensation 2,632 2,960 Net operating losses 111,580 56,788 Other 63 69 Noncurrent deferred tax assets 119,075 66,479 Total deferred tax assets 119,075 66,479 Valuation allowance — (1,151 ) Total deferred tax assets — net 119,075 65,328 Deferred Income Tax Liabilities Property and equipment (172,164 ) (68,811 ) Prepaid expenses (1,194 ) (965 ) Other — (131 ) Noncurrent deferred tax liabilities (173,358 ) (69,907 ) Net deferred tax liability $ (54,283 ) $ (4,579 )

COMMITMENTS AND CONTINGENCIES (

COMMITMENTS AND CONTINGENCIES (Tables)	12 Months Ended
	Dec. 31, 2018
Commitments and Contingencies Disclosure [Abstract]
Schedule of future minimum rental payments for operating leases	Required remaining lease payments for each fiscal year are as follows: ($ in thousands) 2019 $ 892 2020 721 2021 721 2022 721 2023 and thereafter 2,258 Total $ 5,313

QUARTERLY FINANCIAL DATA (UNA_2

QUARTERLY FINANCIAL DATA (UNAUDITED) (Tables)	12 Months Ended
	Dec. 31, 2018
Quarterly Financial Information Disclosure [Abstract]
Quarterly Financial Data	The following table sets forth our unaudited quarterly results for each of the last four quarters for the years ended December 31, 2018 and 2017 . This unaudited quarterly information has been prepared on the same basis as our annual audited financial statements and includes all adjustments, consisting only of normal recurring adjustments that are necessary to present fairly the financial information for the fiscal quarters presented. 2018 (In thousands, except for per share data) First Quarter Second Quarter Third Quarter Fourth Quarter Service revenue $ 385,219 $ 459,888 $ 434,041 $ 425,414 Gross profit $ 87,097 $ 108,000 $ 113,895 $ 124,993 Net income $ 36,708 $ 39,091 $ 46,285 $ 51,778 Net income per common share: Basic $ 0.44 $ 0.47 $ 0.55 $ 0.62 Diluted $ 0.42 $ 0.45 $ 0.53 $ 0.59 Weighted average common shares outstanding: Basic 83,081 83,447 83,544 83,758 Diluted 86,848 86,878 86,878 87,218 2017 (In thousands, except for per share data) First Quarter Second Quarter Third Quarter Fourth Quarter Service revenue $ 171,931 $ 213,492 $ 282,730 $ 313,712 Gross profit $ 22,366 $ 36,715 $ 57,297 $ 51,664 Net income (loss) $ (24,351 ) $ 4,921 $ 21,965 $ 10,078 Net income (loss) per common share: Basic $ (0.43 ) $ 0.06 $ 0.26 $ 0.12 Diluted $ (0.43 ) $ 0.06 $ 0.25 $ 0.12 Weighted average common shares outstanding: Basic 55,996 83,040 83,040 83,040 Diluted 55,996 86,279 86,264 86,818

ORGANIZATION AND HISTORY (Detai

ORGANIZATION AND HISTORY (Details) $ / shares in Units, hydraulic_horse_power in Thousands, $ in Thousands	Dec. 31, 2018USD ($)hydraulic_horse_powerfleetcoiled_tubing_unit$ / sharesshares	Mar. 22, 2017USD ($)$ / sharesshares	Dec. 22, 2016shares	Dec. 31, 2018USD ($)fleet$ / sharesshares	Dec. 31, 2017USD ($)$ / sharesshares	Dec. 31, 2016USD ($)	Nov. 24, 2015fleet	Sep. 30, 2013$ / shares
Class of Stock [Line Items]
Stock split ratio			0.0059
Stock, shares authorized (in shares) | shares			230,000,000
Common stock, authorized (in shares) | shares	200,000,000		200,000,000	200,000,000	200,000,000
Preferred stock, authorized (in shares) | shares	30,000,000		30,000,000	30,000,000	30,000,000
Common stock, par value (in dollars per share) | $ / shares	$ 0.001			$ 0.001	$ 0.001			$ 0.001
Proceeds from IPO | $				$ 0	$ 185,500	$ 0
Repayment of outstanding borrowings | $		$ 71,800		80,946	166,546	41,295
Funds to purchase additional hydraulic fracturing fleets and other equipment | $		$ 86,800		$ 284,197	$ 285,891	$ 42,832
Number of hydraulic fracturing fleets | fleet							3
Pioneer and Pioneer Pumping Services
Class of Stock [Line Items]
Payments for asset acquisition | $	$ 110,000
Stock Issued in asset acquisition | shares	16,600,000
Asset acquisition costs | $	$ 3,400
Service provider, term	10 years
Number of hydraulic fracturing fleets | fleet	8			8
Hydraulic fracturing fleet, hydraulic horse power (HHP) | hydraulic_horse_power	510
Number of coiled tubing units | coiled_tubing_unit	4
IPO
Class of Stock [Line Items]
Shares of common stock sold, including shares sold by third parties (in shares) | shares		25,000,000
Common stock, par value (in dollars per share) | $ / shares		$ 0.001
Stock price (in dollars per share) | $ / shares		$ 14
Proceeds from IPO | $		$ 170,100
Payment of underwriting discounts and commissions | $		10,900
Payments of stock issuance costs, other | $		$ 4,500
IPO | Series A Preferred Stock
Class of Stock [Line Items]
Number of shares of outstanding stock converted (in shares) | shares		16,999,990
IPO | March 2017 Stock Split
Class of Stock [Line Items]
Stock split ratio		1.45
IPO | Series A Preferred Stock Converted To Common Stock | Series A Preferred Stock
Class of Stock [Line Items]
Stock split ratio		1
IPO sold by Company
Class of Stock [Line Items]
Shares of common stock sold, including shares sold by third parties (in shares) | shares		13,250,000
IPO sold by existing stockholders
Class of Stock [Line Items]
Shares of common stock sold, including shares sold by third parties (in shares) | shares		11,750,000

SIGNIFICANT ACCOUNTING POLICI_4

SIGNIFICANT ACCOUNTING POLICIES (Details) - USD ($)	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2014	Dec. 31, 2011	Jan. 01, 2019
Accounting Policies [Abstract]
Allowance for doubtful accounts	$ 100,000	$ 400,000	$ 600,000
Loss on disposal of assets	59,220,000	39,086,000	22,529,000
Property, Plant and Equipment [Line Items]
Accrued revenue	18,000,000	24,800,000
Property and equipment impairment expense	0	0	6,305,000
Goodwill	9,425,000	9,425,000	9,425,000
Goodwill impairment expense	0	0	1,177,000
Premiums Receivable, Allowance for Doubtful Accounts, Additions for Charges to Expense	100,000
Allowance for Doubtful Accounts Receivable, Recoveries	400,000
Advertising expense	1,300,000	800,000	400,000
Amortization of deferred debt issuance costs	403,000	3,403,000	2,091,000
Accounting Standards Update 2016-02
Property, Plant and Equipment [Line Items]
Operating lease, right-of-use asset						$ 10,000,000
Operating lease, liability						$ 10,000,000
Blackrock Drilling, Inc
Property, Plant and Equipment [Line Items]
Consideration transferred				$ 1,800,000
Property, plant, and equipment				600,000
Goodwill				$ 1,200,000
Goodwill impairment expense			1,200,000
Technology Stimulation Services, LLC
Property, Plant and Equipment [Line Items]
Consideration transferred					$ 24,400,000
Property, plant, and equipment					15,000,000
Goodwill					$ 9,400,000
Goodwill impairment expense		0	0
All Other
Accounting Policies [Abstract]
Loss on disposal of assets	(742,000)	1,027,000	(1,161,000)
Property, Plant and Equipment [Line Items]
Property and equipment impairment expense			6,305,000
Goodwill	0	0	0
Goodwill impairment expense			1,177,000
All Other | Blackrock Drilling, Inc
Property, Plant and Equipment [Line Items]
Goodwill impairment expense			1,200,000
Pressure Pumping
Accounting Policies [Abstract]
Loss on disposal of assets	59,962,000	38,059,000	23,690,000
Property, Plant and Equipment [Line Items]
Property and equipment impairment expense			0
Goodwill	9,425,000	$ 9,425,000	9,425,000
Goodwill impairment expense			$ 0
Pressure Pumping | Technology Stimulation Services, LLC
Property, Plant and Equipment [Line Items]
Goodwill	$ 9,400,000
Building | Minimum
Property, Plant and Equipment [Line Items]
Estimated useful lives	P5Y
Building | Maximum
Property, Plant and Equipment [Line Items]
Estimated useful lives	P30Y
Vehicles | Minimum
Property, Plant and Equipment [Line Items]
Estimated useful lives	P1Y
Vehicles | Maximum
Property, Plant and Equipment [Line Items]
Estimated useful lives	P5Y
Equipment | Minimum
Property, Plant and Equipment [Line Items]
Estimated useful lives	P1Y
Equipment | Maximum
Property, Plant and Equipment [Line Items]
Estimated useful lives	P20Y
Leasehold improvements | Minimum
Property, Plant and Equipment [Line Items]
Estimated useful lives	P5Y
Leasehold improvements | Maximum
Property, Plant and Equipment [Line Items]
Estimated useful lives	P20Y

SIGNIFICANT ACCOUNTING POLICI_5

SIGNIFICANT ACCOUNTING POLICIES Remaining Performance Obligation (Details) - USD ($) $ in Millions	Dec. 31, 2018	Dec. 31, 2017
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2018-01-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, remaining performance obligation		$ 26.4
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2019-01-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, remaining performance obligation	$ 43.9

SUPPLEMENTAL CASH FLOWS INFOR_3

SUPPLEMENTAL CASH FLOWS INFORMATION (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Supplemental cash flows disclosures
Interest paid	$ 5,068	$ 3,966	$ 18,249
Income taxes paid	0	0	3
Supplemental disclosure of non‑cash investing and financing activities
Capital expenditures included in accounts payable and accrued liabilities	137,647	33,850	3,176
Conversion of preferred stock to common stock at Initial Public Offering	0	162,511	0
Non-cash purchases of property and equipment	$ 204,512	$ 0	$ 0

FAIR VALUE MEASUREMENTS - Addit

FAIR VALUE MEASUREMENTS - Additional Information (Details) - USD ($)	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Property and equipment impairment expense	$ 0	$ 0	$ 6,305,000
Net carrying value of property and equipment	912,846,000	470,910,000
Additions or disposals of goodwill	0	0	0
Goodwill impairment expense	$ 0	0	1,177,000
Drilling
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Property and equipment impairment expense			6,300,000
Net carrying value of property and equipment				$ 15,000,000
Surface air drilling unit
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Goodwill impairment expense			1,200,000
Fair value of the reporting unit			3,800,000
Carrying value of reporting unit			4,200,000
Implied fair value of goodwill			0
Interest rate swap
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Gain (loss) interest rate swap		300,000	200,000
Interest rate swap | Recurring basis
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value of interest rate swap liability		$ 0	$ 300,000

FAIR VALUE MEASUREMENTS - Asset

FAIR VALUE MEASUREMENTS - Assets Measured at Fair Value on a Nonrecurring Basis (Details) - USD ($)	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total gains (losses)	$ 0	$ 0	$ (6,305,000)
Total gains (losses)	$ 0	$ 0	$ (1,177,000)

INTANGIBLE ASSETS - Additional

INTANGIBLE ASSETS - Additional Information (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Goodwill and Intangible Assets Disclosure [Abstract]
Useful life	5 years
Amortization expense	$ 0.3	$ 0.3	$ 0.3
Remaining amortization period	17 days

INTANGIBLE ASSETS - Intangible

INTANGIBLE ASSETS - Intangible Assets Subject to Amortization (Details) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Goodwill and Intangible Assets Disclosure [Abstract]
Internally developed software	$ 1,440	$ 1,440
Less accumulated amortization	1,427	1,139
Intangible assets — net	$ 13	$ 301

INTANGIBLE ASSETS - Estimated R

INTANGIBLE ASSETS - Estimated Remaining Amortization Expense (Details) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Goodwill and Intangible Assets Disclosure [Abstract]
2,019	$ 13
2,020	0
Intangible assets — net	$ 13	$ 301

PROPERTY AND EQUIPMENT (Details

PROPERTY AND EQUIPMENT (Details) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Property, Plant and Equipment [Line Items]
Subtotal	$ 1,142,448	$ 651,787
Less accumulated depreciation	229,602	180,877
Property and equipment — net	912,846	470,910
Land
Property, Plant and Equipment [Line Items]
Subtotal	7,669	0
Building
Property, Plant and Equipment [Line Items]
Subtotal	23,840	0
Equipment and vehicles
Property, Plant and Equipment [Line Items]
Subtotal	1,105,380	646,800
Leasehold improvements
Property, Plant and Equipment [Line Items]
Subtotal	$ 5,559	$ 4,987

IMPAIRMENT OF LONG_LIVED ASSE_2

IMPAIRMENT OF LONG‑LIVED ASSETS (Details) - USD ($)	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Segment Reporting Information [Line Items]
Property and equipment impairment expense	$ 0	$ 0	$ 6,305,000
Net carrying value of property and equipment	$ 912,846,000	$ 470,910,000
Drilling
Segment Reporting Information [Line Items]
Property and equipment impairment expense			6,300,000
Net carrying value of property and equipment				$ 15,000,000
Drilling | Significant other observable inputs (Level 2)
Segment Reporting Information [Line Items]
Fair value of the reporting unit			$ 8,700,000

DEFERRED REVENUE REBATE (Detail

DEFERRED REVENUE REBATE (Details) - USD ($)	1 Months Ended	12 Months Ended
	Nov. 30, 2011	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Debt Instrument [Line Items]
Fracturing services, period	78 months
Estimated fair value of equipment	$ 13,000,000	$ 592,602,000	$ 305,299,000	$ 46,008,000
Deferred revenue	$ 12,000,000	0	615,000
Amortization as a reduction of revenue		$ 615,000	$ 1,846,000	$ 1,846,000
Equipment financing | Note payable
Debt Instrument [Line Items]
Stated interest rate	12.00%
Debt instrument, face amount	$ 25,000,000

LONG_TERM DEBT - Additional Inf

LONG‑TERM DEBT - Additional Information (Details)	Dec. 19, 2018USD ($)	Feb. 22, 2018USD ($)	Mar. 22, 2017USD ($)	Jan. 13, 2017USD ($)	Jun. 16, 2016USD ($)	Jun. 08, 2016USD ($)	Nov. 24, 2015USD ($)fleet	Sep. 30, 2013USD ($)	Dec. 31, 2018USD ($)	Dec. 31, 2017USD ($)	Dec. 31, 2016USD ($)
Debt Instrument [Line Items]
Proceeds from additional common equity capitalization									$ 0	$ 0	$ 40,425,000
Debt instrument, covenant, additional capital, reserved for working capital						$ 10,000,000
Debt instrument, covenant, additional capital, available for repurchase of debt						$ 30,000,000
Debt instrument, covenant, financial statements, past due, period						30 days
Debt instrument, repurchase price to par					$ 0.80
Debt instrument, repurchase price, discount to par, percentage					20.00%
Extinguishment of debt					$ 37,500,000
Early repayment of senior debt					30,000,000				0	0	30,000,000
Payments of debt extinguishment costs					500,000				0	0	525,000
Gain on extinguishment of debt					$ 7,000,000				0	0	6,975,000
Repayments of borrowings			$ 71,800,000						$ 80,946,000	$ 166,546,000	$ 41,295,000
Debt instrument, term							36 months
Number of hydraulic fracturing fleets | fleet							3
Proceeds from debt							$ 25,000,000
Maximum
Debt Instrument [Line Items]
Debt instrument, covenant, leverage ratio, maximum								3.5
6.25% Term loan | 6.25% Term loan
Debt Instrument [Line Items]
Debt instrument, face amount								$ 220,000,000
Repayments of debt				$ 75,000,000
Revolving Credit Facility | Line of Credit
Debt Instrument [Line Items]
Line of credit facility, maximum borrowing capacity								$ 40,000,000
Debt instrument, interest rate, stated percentage								6.25%
Debt instrument, variable floor rate								1.00%
Repayments of borrowings				$ 13,500,000
ABL Credit Facility | Line of Credit
Debt Instrument [Line Items]
Line of credit facility, maximum borrowing capacity	$ 300,000,000	$ 200,000,000	$ 150,000,000
Line of credit facility, expiration period			5 years
Line of credit facility, borrowing base, accounts receivable percentage			85.00%
Line of credit, springing fixed charge coverage ratio			1
Line of credit facility, coverage ratio establishing threshold, option one, percentage of facility size and borrowing base	10.00%	10.00%	10.00%
Line of credit facility, coverage ratio establishing threshold, option two, amount	$ 22,500,000	$ 15,000,000	$ 12,000,000
Line of credit facility, commitment fee, utilization percentage, threshold			50.00%
ABL Credit Facility | Line of Credit | Minimum
Debt Instrument [Line Items]
Line of credit facility, commitment fee percentage			0.25%
ABL Credit Facility | Line of Credit | Maximum
Debt Instrument [Line Items]
Line of credit facility, commitment fee percentage			0.38%
ABL Credit Facility | Line of Credit | London Interbank Offered Rate (LIBOR) | Minimum
Debt Instrument [Line Items]
Debt instrument, basis spread on variable rate			1.75%
ABL Credit Facility | Line of Credit | London Interbank Offered Rate (LIBOR) | Maximum
Debt Instrument [Line Items]
Debt instrument, basis spread on variable rate			2.25%
ABL Credit Facility | Line of Credit | Base Rate | Minimum
Debt Instrument [Line Items]
Debt instrument, basis spread on variable rate			0.75%
ABL Credit Facility | Line of Credit | Base Rate | Maximum
Debt Instrument [Line Items]
Debt instrument, basis spread on variable rate			1.25%
Investor
Debt Instrument [Line Items]
Proceeds from additional common equity capitalization						$ 400,000
Energy Capital Partners | Majority Shareholder
Debt Instrument [Line Items]
Proceeds from additional common equity capitalization						$ 40,000,000

LONG_TERM DEBT - Schedule of De

LONG‑TERM DEBT - Schedule of Debt (Details) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Debt Instrument [Line Items]
Total debt	$ 70,000	$ 72,942
Less current portion of long-term debt	0	15,764
Total long-term debt, net of deferred loan costs	70,000	57,178
Line of Credit | ABL Credit Facility
Debt Instrument [Line Items]
Total debt	70,000	55,000
Equipment financing | Equipment financing
Debt Instrument [Line Items]
Total debt	$ 0	$ 17,942

LONG_TERM DEBT - Maturities of

LONG‑TERM DEBT - Maturities of Long-term Debt (Details) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Debt Disclosure [Abstract]
2,019	$ 0
2,020	0
2,021	0
2,022	0
2023 and thereafter	70,000
Total	$ 70,000	$ 72,942

ACCRUED LIABILITIES (Details)

ACCRUED LIABILITIES (Details) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Other Liabilities Disclosure [Abstract]
Accrued capital expenditure	$ 109,832	$ 0
Accrued insurance	3,905	2,762
Accrued payroll and related expenses	15,854	10,110
Accrued taxes and others	8,498	3,735
Total	$ 138,089	$ 16,607

EMPLOYEE BENEFIT PLAN (Details)

EMPLOYEE BENEFIT PLAN (Details) - USD ($) $ in Thousands	Jan. 01, 2019	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Retirement Benefits [Abstract]
Employee minimum service period	60 days	6 months
Employee maximum annual contribution	$ 19	$ 15
Annual vesting percentage of company contributions	25.00%	25.00%
Vesting term	4 years	5 years
Employer match percentage of employee contribution	100.00%	20.00%
Maximum annual match, percentage of gross salary	6.00%	10.00%
Plan expense		$ 300	$ 200	$ 200

REPORTABLE SEGMENT INFORMATIO_2

REPORTABLE SEGMENT INFORMATION - Additional Information (Details) $ in Millions	Aug. 31, 2018USD ($)	Dec. 31, 2018segment
Segment Reporting [Abstract]
Number of operating segments		5
Disposal Group, Not Discontinued Operation, Gain (Loss) on Disposal | $	$ (0.3)
Number of Reportable Segments		1

REPORTABLE SEGMENT INFORMATIO_3

REPORTABLE SEGMENT INFORMATION - Reconciliation of Segment Information (Details) - USD ($)	1 Months Ended	12 Months Ended
	Nov. 30, 2011	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Segment Reporting Information [Line Items]
Service revenue		$ 1,704,562,000	$ 981,865,000	$ 436,920,000
Adjusted EBITDA		388,523,000	137,443,000	7,816,000
Depreciation and amortization		88,138,000	55,628,000	43,542,000
Property and equipment impairment expense		0	0	6,305,000
Goodwill impairment expense		0	0	1,177,000
Capital expenditures	$ 13,000,000	592,602,000	305,299,000	46,008,000
Goodwill		9,425,000	9,425,000	9,425,000
Total assets		1,274,522,000	719,032,000	541,422,000
Pressure Pumping
Segment Reporting Information [Line Items]
Service revenue		1,658,403,000	945,040,000	409,014,000
Adjusted EBITDA		398,396,000	145,122,000	15,656,000
Depreciation and amortization		83,404,000	51,155,000	37,282,000
Property and equipment impairment expense				0
Goodwill impairment expense				0
Capital expenditures		577,171,000	300,406,000	45,473,000
Goodwill		9,425,000	9,425,000	9,425,000
Total assets		1,230,830,000	688,279,000	501,906,000
All Other
Segment Reporting Information [Line Items]
Service revenue		46,159,000	36,825,000	27,906,000
Adjusted EBITDA		(9,873,000)	(7,679,000)	(7,840,000)
Depreciation and amortization		4,734,000	4,473,000	6,260,000
Property and equipment impairment expense				6,305,000
Goodwill impairment expense				1,177,000
Capital expenditures		15,431,000	4,893,000	535,000
Goodwill		0	0	0
Total assets		$ 43,692,000	$ 30,753,000	$ 39,516,000

REPORTABLE SEGMENT INFORMATIO_4

REPORTABLE SEGMENT INFORMATION - Reconciliation of Net Income (Loss) to Adjusted EBITDA (Details) - USD ($)	Jun. 16, 2016	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Segment Reporting Information [Line Items]
Net income (loss)		$ 173,862,000	$ 12,613,000	$ (53,147,000)
Depreciation and amortization		88,138,000	55,628,000	43,542,000
Interest expense		6,889,000	7,347,000	20,387,000
Income tax expense (benefit)		51,255,000	3,128,000	(27,972,000)
Loss (gain) on disposal of assets		59,220,000	39,086,000	22,529,000
Property and equipment impairment expense		0	0	6,305,000
Goodwill impairment expense		0	0	1,177,000
Gain on extinguishment of debt	$ (7,000,000)	0	0	(6,975,000)
Stock-based compensation		5,482,000	9,489,000	1,649,000
Other expense		663,000	1,025,000	321,000
Other general and administrative expense		205,000	722,000
Deferred IPO Bonus		2,809,000	8,405,000
Adjusted EBITDA		388,523,000	137,443,000	7,816,000
Pressure Pumping
Segment Reporting Information [Line Items]
Net income (loss)		253,196,000	50,417,000	(45,316,000)
Depreciation and amortization		83,404,000	51,155,000	37,282,000
Interest expense		0	0	0
Income tax expense (benefit)		0	0	0
Loss (gain) on disposal of assets		59,962,000	38,059,000	23,690,000
Property and equipment impairment expense				0
Goodwill impairment expense				0
Gain on extinguishment of debt				0
Stock-based compensation		0	0	0
Other expense		0	0	0
Other general and administrative expense		2,000	0
Deferred IPO Bonus		1,832,000	5,491,000
Adjusted EBITDA		398,396,000	145,122,000	15,656,000
All Other
Segment Reporting Information [Line Items]
Net income (loss)		(79,334,000)	(37,804,000)	(7,831,000)
Depreciation and amortization		4,734,000	4,473,000	6,260,000
Interest expense		6,889,000	7,347,000	20,387,000
Income tax expense (benefit)		51,255,000	3,128,000	(27,972,000)
Loss (gain) on disposal of assets		(742,000)	1,027,000	(1,161,000)
Property and equipment impairment expense				6,305,000
Goodwill impairment expense				1,177,000
Gain on extinguishment of debt				(6,975,000)
Stock-based compensation		5,482,000	9,489,000	1,649,000
Other expense		663,000	1,025,000	321,000
Other general and administrative expense		203,000	722,000
Deferred IPO Bonus		977,000	2,914,000
Adjusted EBITDA		$ (9,873,000)	$ (7,679,000)	$ (7,840,000)

REPORTABLE SEGMENT INFORMATIO_5

REPORTABLE SEGMENT INFORMATION - Major Customers (Details) - Total revenue	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Customer Concentration Risk | Customer A
Revenue, Major Customer [Line Items]
Concentration risk percentage	24.10%	15.00%	18.00%
Customer Concentration Risk | Customer B
Revenue, Major Customer [Line Items]
Concentration risk percentage	16.50%	13.80%	12.50%
Customer Concentration Risk | Customer C
Revenue, Major Customer [Line Items]
Concentration risk percentage	12.20%	12.70%	8.70%
Customer Concentration Risk | Customer D
Revenue, Major Customer [Line Items]
Concentration risk percentage	8.90%	12.60%	7.00%
Customer Concentration Risk | Customer E
Revenue, Major Customer [Line Items]
Concentration risk percentage	7.10%	11.80%	0.00%
Pressure Pumping Revenue | Product Concentration Risk | Customer A
Revenue, Major Customer [Line Items]
Concentration risk percentage	97.40%	99.90%	96.00%
Pressure Pumping Revenue | Product Concentration Risk | Customer B
Revenue, Major Customer [Line Items]
Concentration risk percentage	98.30%	99.20%	99.00%
Pressure Pumping Revenue | Product Concentration Risk | Customer C
Revenue, Major Customer [Line Items]
Concentration risk percentage	100.00%	99.90%	100.00%
Pressure Pumping Revenue | Product Concentration Risk | Customer D
Revenue, Major Customer [Line Items]
Concentration risk percentage	100.00%	99.80%	99.00%
Pressure Pumping Revenue | Product Concentration Risk | Customer E
Revenue, Major Customer [Line Items]
Concentration risk percentage	100.00%

NET INCOME (LOSS) PER SHARE - C

NET INCOME (LOSS) PER SHARE - Calculation of Net Income (Loss) Per Share (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Numerator (both basic and diluted)
Net income (loss) relevant to common stockholders									$ 173,862	$ 12,613	$ (53,147)
Denominator
Denominator for basic income (loss) per share (in shares)	83,758	83,544	83,447	83,081	83,040	83,040	83,040	55,996	83,460	76,371	44,787
Denominator for diluted income (loss) per share (in shares)	87,218	86,878	86,878	86,848	86,818	86,264	86,279	55,996	87,046	79,583	44,787
Basic net income (loss) per common share (in dollars per share)	$ 0.62	$ 0.55	$ 0.47	$ 0.44	$ 0.12	$ 0.26	$ 0.06	$ (0.43)	$ 2.08	$ 0.17	$ (1.19)
Diluted net income (loss) per common share (in dollars per share)	$ 0.59	$ 0.53	$ 0.45	$ 0.42	$ 0.12	$ 0.25	$ 0.06	$ (0.43)	$ 2	$ 0.16	$ (1.19)
Stock options
Denominator
Dilutive effect of stock options/units (in shares)									3,129	2,903	0
Performance stock units
Denominator
Dilutive effect of stock options/units (in shares)									277	59	0
Restricted stock units
Denominator
Dilutive effect of stock options/units (in shares)									180	250	0

NET INCOME (LOSS) PER SHARE - A

NET INCOME (LOSS) PER SHARE - Anti-dilutive Shares Excluded from Calculation (Details) - shares shares in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Anti-dilutive securities (in shares)	0	0	22,018
Stock options
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Anti-dilutive securities (in shares)	0	0	4,646
Preferred stock
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Anti-dilutive securities (in shares)	0	0	17,000
Performance stock units
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Anti-dilutive securities (in shares)	0	0	0
Non-vested restricted stock units
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Anti-dilutive securities (in shares)	0	0	372

STOCK_BASED COMPENSATION - Addi

STOCK‑BASED COMPENSATION - Additional Information (Details)

Mar. 22, 2017shares

Mar. 16, 2017USD ($)installmentshares

Jul. 19, 2016installmentshares

Dec. 31, 2014

Dec. 01, 2013installmentshares

Sep. 30, 2013$ / sharesshares

Jun. 14, 2013shares

Dec. 31, 2018USD ($)$ / sharesshares

Dec. 31, 2017USD ($)$ / shares

Dec. 31, 2016USD ($)$ / shares

Dec. 31, 2014$ / sharesshares

Mar. 31, 2017shares

Mar. 04, 2014shares

Share-based Compensation Arrangement by Share-based Payment Award [Line Items]

Options granted (in shares)

0

Outstanding value of options (in dollars per share) | $ / shares

$ 0

Forfeited (in shares)

29,255

Deferred IPO Bonus | $

$ 2,809,000

$ 8,405,000

Granted (in dollars per share) | $ / shares

$ 0

$ 3.35

$ 1.77

Options, outstanding, intrinsic value | $

$ 34,000,000

Options, exercisable, intrinsic value | $

34,000,000

Options, exercises in period, intrinsic value | $

$ 700,000

Options, outstanding, weighted average remaining contractual term

5 years 10 months 13 days

Options, exercisable, weighted average remaining contractual term

5 years 6 months 29 days

Common stock, par value (in dollars per share) | $ / shares

$ 0.001

$ 0.001

$ 0.001

Non-vested restricted stock units

Share-based Compensation Arrangement by Share-based Payment Award [Line Items]

Granted (in dollars per share) | $ / shares

$ 3.89

Target Shares Granted (in shares)

372,335

372,335

319,250

Restricted stock units, conversion of stock, conversion rights (in shares)

1

Performance stock units

Share-based Compensation Arrangement by Share-based Payment Award [Line Items]

Target Shares Granted (in shares)

178,975

Stock Option Plan

Share-based Compensation Arrangement by Share-based Payment Award [Line Items]

Number of shares authorized (in shares)

4,645,884

Stock Option Plan | Stock options

Share-based Compensation Arrangement by Share-based Payment Award [Line Items]

Options granted (in shares)

3,499,228

Outstanding value of options (in dollars per share) | $ / shares

$ 3.96

Expiration period

10 years

Incentive Award Plan

Share-based Compensation Arrangement by Share-based Payment Award [Line Items]

Number of shares authorized (in shares)

5,800,000

Compensation cost not yet recognized, period for recognition

1 year 11 months 19 days

Tax benefit from compensation expense | $

$ 5,500,000

$ 9,500,000

$ 1,600,000

Compensation not yet recognized, stock options | $

11,500,000

Incentive Award Plan | Non-vested restricted stock units

Share-based Compensation Arrangement by Share-based Payment Award [Line Items]

Stock-based compensation | $

$ 2,900,000

6,168,081.03

0

Target Shares Granted (in shares)

319,250

Restricted stock units, conversion of stock, conversion rights (in shares)

1

Compensation not yet recognized, other than options | $

$ 5,700,000

Compensation cost not yet recognized, period for recognition

1 year 7 months 6 days

Incentive Award Plan | Performance stock units

Share-based Compensation Arrangement by Share-based Payment Award [Line Items]

Stock-based compensation | $

$ 2,000,000

400,000

0

June 14, 2013 | Stock Option Plan | Stock options

Share-based Compensation Arrangement by Share-based Payment Award [Line Items]

Options granted (in shares)

2,799,408

Expiration period

10 years

Award vesting rights

25.00%

December 1, 2013 | Stock Option Plan | Stock options

Share-based Compensation Arrangement by Share-based Payment Award [Line Items]

Options granted (in shares)

699,820

Expiration period

10 years

Forfeited (in shares)

114,456

Deferred IPO Bonus | $

$ 5,100,000

Number of installments | installment

4

July 19, 2016 | Stock Option Plan | Stock options

Share-based Compensation Arrangement by Share-based Payment Award [Line Items]

Options granted (in shares)

1,274,549

Expiration period

10 years

Number of installments | installment

5

March 16, 2017 | Stock Option Plan | Stock options

Share-based Compensation Arrangement by Share-based Payment Award [Line Items]

Options granted (in shares)

793,738

Expiration period

10 years

Stock-based compensation | $

$ 600,000

$ 2,909,790.12

$ 1,649,282.42

Number of installments | installment

4

STOCK_BASED COMPENSATION - Fair

STOCK‑BASED COMPENSATION - Fair Value Of Options (Details) - Stock Option Plan - Stock options - USD ($)	Mar. 16, 2017	Jul. 19, 2016	Dec. 01, 2013	Jun. 14, 2013
June 14, 2013
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expected volatility				45.00%
Expected dividends				$ 0
Expected term (in years)				6 years 3 months
Risk free rate				1.35%
December 1, 2013
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expected volatility			45.00%
Expected dividends			$ 0
Expected term (in years)			6 years 3 months
Risk free rate			1.83%
July 19, 2016
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expected volatility		55.00%
Expected dividends		$ 0
Expected term (in years)		5 years 9 months
Risk free rate		1.22%
March 16, 2017
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expected volatility	18.00%
Expected dividends	$ 0
Expected term (in years)	6 years 3 months
Risk free rate	2.23%

STOCK_BASED COMPENSATION - Summ

STOCK‑BASED COMPENSATION - Summary Of Stock Option Activity (Details)	12 Months Ended
	Dec. 31, 2018$ / sharesshares
Number of Shares
Outstanding beginning balance (in shares) | shares	4,636,353
Granted (in shares) | shares	0
Exercised (in shares) | shares	(49,912)
Forfeited (in shares) | shares	(29,255)
Expired (in shares) | shares	0
Canceled (in shares) | shares	0
Outstanding ending balance (in shares) | shares	4,557,186
Exercisable ending balance (in shares) | shares	3,994,990
Weighted Average Exercise Price
Outstanding beginning balance (in dollars per share) | $ / shares	$ 5.20
Granted (in dollars per share) | $ / shares	0
Exercised (in dollars per share) | $ / shares	4.95
Forfeited (in dollars per share) | $ / shares	14
Expired (in dollars per share) | $ / shares	0
Canceled (in dollars per share) | $ / shares	0
Outstanding ending balance (in dollars per share) | $ / shares	5.14
Exercisable ending balance (in dollars per share) | $ / shares	$ 3.90

STOCK_BASED COMPENSATION - Su_2

STOCK‑BASED COMPENSATION - Summary Of RSU Activity (Details) - Non-vested restricted stock units - $ / shares	Mar. 22, 2017	Sep. 30, 2013	Dec. 31, 2018
Number of Shares
Outstanding at Beginning of Period (in shares)			688,744
Granted (in shares)	372,335	372,335	319,250
Vested (in shares)			(500,360)
Exercised (in shares)			0
Forfeited (in shares)			(34,129)
Expired (in shares)			0
Canceled (in shares)			0
Outstanding at End of Period (in shares)			473,505
Weighted Average Grant Date Fair Value
Outstanding at Beginning of Period (in dollars per share)			$ 13.66
Granted (in dollars per share)			18.49
Vested (in dollars per share)			13.87
Exercised (in dollars per share)			0
Forfeited (in dollars per share)			15.99
Expired (in dollars per share)			0
Canceled (in dollars per share)			0
Outstanding at End of Period (in dollars per share)			$ 16.52

STOCK_BASED COMPENSATION - Su_3

STOCK‑BASED COMPENSATION - Summary Of Performance Shares Activity (Details) - Performance stock units	12 Months Ended
	Dec. 31, 2018$ / sharesshares
Share-based Compensation Arrangement by Share-based Payment Award, Non-Option Equity Instruments, Outstanding [Roll Forward]
Outstanding at Beginning of Period (in shares)	169,635
Target Shares Granted (in shares)	178,975
Target Shares Vested (in shares)	0
Target Shares Forfeited (in shares)	0
Outstanding at End of Period (in shares)	348,610
Weighted Average Grant Date Fair Value per Share (in dollars per share) | $ / shares	$ 19.34
2,016
Share-based Compensation Arrangement by Share-based Payment Award, Non-Option Equity Instruments, Outstanding [Roll Forward]
Outstanding at Beginning of Period (in shares)	169,635
Target Shares Granted (in shares)	0
Target Shares Vested (in shares)	0
Target Shares Forfeited (in shares)	0
Outstanding at End of Period (in shares)	169,635
Weighted Average Grant Date Fair Value per Share (in dollars per share) | $ / shares	$ 10.73
2,017
Share-based Compensation Arrangement by Share-based Payment Award, Non-Option Equity Instruments, Outstanding [Roll Forward]
Outstanding at Beginning of Period (in shares)	0
Target Shares Granted (in shares)	178,975
Target Shares Vested (in shares)	0
Target Shares Forfeited (in shares)	0
Outstanding at End of Period (in shares)	178,975
Weighted Average Grant Date Fair Value per Share (in dollars per share) | $ / shares	$ 27.51

INCOME TAXES - Additional Infor

INCOME TAXES - Additional Information (Details) $ in Millions	12 Months Ended
	Dec. 31, 2018USD ($)
Operating Loss Carryforwards [Line Items]
Federal statutory income tax rate	21.00%
Change in tax rate provisional income tax expense benefit	$ 3.4
Change in tax rate deferred tax liability income tax expense	3.4
Federal
Operating Loss Carryforwards [Line Items]
Operating loss carryforwards	516
State
Operating Loss Carryforwards [Line Items]
Operating loss carryforwards	$ 50

INCOME TAXES - Tax Provision_Be

INCOME TAXES - Tax Provision/Benefit (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Federal:
Current	$ 0	$ (376)	$ 0
Deferred	48,738	3,634	(29,082)
Federal income tax expense (benefit)	48,738	3,258	(29,082)
State:
Current	1,551	74	0
Deferred	966	(204)	1,110
State income tax expense (benefit)	2,517	(130)	1,110
Income tax expense (benefit)	$ 51,255	$ 3,128	$ (27,972)

INCOME TAXES - Tax Reconciliati

INCOME TAXES - Tax Reconciliation (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Income Tax Disclosure [Abstract]
Tax at federal statutory rate	$ 47,275	$ 5,510	$ (28,392)
State taxes, net of federal benefit	1,874	176	(216)
Non-deductible expenses	2,423	1,582	498
Stock-based compensation	(426)	(655)	0
Valuation allowance	(1,151)	273	879
Effect of change in enacted Tax Act	0	(3,448)	0
Other	1,260	(310)	(741)
Income tax expense (benefit)	$ 51,255	$ 3,128	$ (27,972)

INCOME TAXES - Deferred Tax Ass

INCOME TAXES - Deferred Tax Assets and Liabilities (Details) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Deferred Income Tax Assets
Accrued liabilities	$ 769	$ 1,264
Allowance for doubtful accounts	21	94
Goodwill and other intangible assets	4,010	5,304
Stock‑based compensation	2,632	2,960
Net operating losses	111,580	56,788
Other	63	69
Total deferred tax assets	119,075	66,479
Valuation allowance	0	(1,151)
Total deferred tax assets — net	119,075	65,328
Deferred Income Tax Liabilities
Property and equipment	(172,164)	(68,811)
Prepaid expenses	(1,194)	(965)
Other	0	(131)
Noncurrent deferred tax liabilities	(173,358)	(69,907)
Net deferred tax liability	$ (54,283)	$ (4,579)

RELATED_PARTY TRANSACTIONS (Det

RELATED‑PARTY TRANSACTIONS (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2018USD ($)property	Dec. 31, 2017USD ($)	Dec. 31, 2016USD ($)
Related Party Transaction [Line Items]
Payable to related parties	$ 10	$ 20	$ 0
Receivable from related parties	$ 0	0	40
Related party leasing
Related Party Transaction [Line Items]
Lease term	5 years
Extension option term	5 years
Expenses with related party	$ 100
Number of properties adjacent to corporate office subject to leases | property	5
Related party leasing | Property 1
Related Party Transaction [Line Items]
Expenses with related party	$ 30
Related party leasing | Property 2
Related Party Transaction [Line Items]
Expenses with related party	30
Related party leasing | Property 3
Related Party Transaction [Line Items]
Expenses with related party	100
Related party leasing | Property 4
Related Party Transaction [Line Items]
Expenses with related party	100
Related party leasing | Property 5
Related Party Transaction [Line Items]
Expenses with related party	200
Related party transportation services
Related Party Transaction [Line Items]
Expenses with related party	400	300	200
Related party equipment rental
Related Party Transaction [Line Items]
Expenses with related party	$ 200	$ 200	$ 200

COMMITMENTS AND CONTINGENCIES_2

COMMITMENTS AND CONTINGENCIES (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Commitments and Contingencies Disclosure [Abstract]
Operating leases expense	$ 1,700	$ 1,400	$ 1,400
2,019	892
2,020	721
2,021	721
2,022	721
2023 and thereafter	2,258
Total	$ 5,313

EQUITY CAPITALIZATION (Details)

EQUITY CAPITALIZATION (Details) $ / shares in Units, $ in Thousands	Nov. 09, 2017$ / sharesshares	Mar. 22, 2017USD ($)$ / sharesshares	Dec. 27, 2016USD ($)$ / sharesshares	Jun. 08, 2016USD ($)shares	Dec. 31, 2018USD ($)$ / sharesshares	Dec. 31, 2017USD ($)$ / sharesshares	Dec. 31, 2016USD ($)shares	Sep. 30, 2013$ / shares
Subsidiary, Sale of Stock [Line Items]
Proceeds from additional common equity capitalization | $					$ 0	$ 0	$ 40,425
Proceeds from preferred equity capitalization | $			$ 170,000		$ 0	$ 0	170,000
Preferred stock, par value (in dollars per share) | $ / shares					$ 0.001	$ 0.001
Payment of IPO costs | $					$ 0	$ 0	$ 7,489
Preferred stock, issued (in shares) | shares					0	0
Preferred stock, outstanding (in shares) | shares					0	0	16,999,990
Common stock, par value (in dollars per share) | $ / shares					$ 0.001	$ 0.001		$ 0.001
Proceeds from IPO | $					$ 0	$ 185,500	$ 0
Repayment of outstanding borrowings | $		$ 71,800			80,946	166,546	41,295
Capital expenditures | $		$ 86,800			$ 284,197	$ 285,891	$ 42,832
Exercised (in shares) | shares					49,912
Common stock, outstanding (in shares) | shares					100,190,126	83,039,854
Private Placement
Subsidiary, Sale of Stock [Line Items]
Shares of common stock sold, including shares sold by third parties (in shares) | shares			16,999,990
Preferred stock, par value (in dollars per share) | $ / shares			$ 0.001
Payment of IPO costs | $			$ 7,000
Preferred equity capitalization, net of costs | $			$ 163,000
IPO
Subsidiary, Sale of Stock [Line Items]
Shares of common stock sold, including shares sold by third parties (in shares) | shares		25,000,000
Common stock, par value (in dollars per share) | $ / shares		$ 0.001
Stock price (in dollars per share) | $ / shares		$ 14
Proceeds from IPO | $		$ 170,100
Payment of underwriting discounts and commissions | $		10,900
Payments of stock issuance costs, other | $		$ 4,500
IPO Sold By Company
Subsidiary, Sale of Stock [Line Items]
Shares of common stock sold, including shares sold by third parties (in shares) | shares		13,250,000
IPO sold by existing stockholders
Subsidiary, Sale of Stock [Line Items]
Shares of common stock sold, including shares sold by third parties (in shares) | shares		11,750,000
Series A convertible preferred stock
Subsidiary, Sale of Stock [Line Items]
Preferred stock, issued (in shares) | shares							16,999,990
Performance stock units | IPO
Subsidiary, Sale of Stock [Line Items]
Number of shares of outstanding stock converted (in shares) | shares		16,999,990
Series A Preferred Stock Converted To Common Stock | IPO
Subsidiary, Sale of Stock [Line Items]
Shares of common stock issued for each share of preferred stock converted		1
Energy Capital Partners Affiliates
Subsidiary, Sale of Stock [Line Items]
Issuance of common stock (in shares) | shares	13,800,000
Shares issued, price per share (in dollars per share) | $ / shares	$ 15.07
Energy Capital Partners Affiliates
Subsidiary, Sale of Stock [Line Items]
Proceeds from additional common equity capitalization | $				$ 40,400
Issuance of common stock (in shares) | shares				18,007,328

QUARTERLY FINANCIAL DATA (UNA_3

QUARTERLY FINANCIAL DATA (UNAUDITED) (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Quarterly Financial Information Disclosure [Abstract]
Revenue from Contract with Customer, Excluding Assessed Tax	$ 425,414	$ 434,041	$ 459,888	$ 385,219	$ 313,712	$ 282,730	$ 213,492	$ 171,931
Gross profit	124,993	113,895	108,000	87,097	51,664	57,297	36,715	22,366
Net income	$ 51,778	$ 46,285	$ 39,091	$ 36,708	$ 10,078	$ 21,965	$ 4,921	$ (24,351)	$ 232,669	$ 24,113	$ (67,386)
NET INCOME (LOSS) PER COMMON SHARE:
Basic (in dollars per share)	$ 0.62	$ 0.55	$ 0.47	$ 0.44	$ 0.12	$ 0.26	$ 0.06	$ (0.43)	$ 2.08	$ 0.17	$ (1.19)
Diluted (in dollars per share)	$ 0.59	$ 0.53	$ 0.45	$ 0.42	$ 0.12	$ 0.25	$ 0.06	$ (0.43)	$ 2	$ 0.16	$ (1.19)
Weighted average common shares outstanding:
Basic (in shares)	83,758	83,544	83,447	83,081	83,040	83,040	83,040	55,996	83,460	76,371	44,787
Diluted (in shares)	87,218	86,878	86,878	86,848	86,818	86,264	86,279	55,996	87,046	79,583	44,787