Enernoc (ENOC) 10-Q 6 Nov 15 2015 Q3 Quarterly report Financial data

Document and Entity Information

Document and Entity Information - shares	9 Months Ended
	Sep. 30, 2015	Nov. 02, 2015
Document And Entity Information [Abstract]
Trading Symbol	ENOC
Entity Registrant Name	ENERNOC INC
Entity Central Index Key	1,244,937
Current Fiscal Year End Date	--12-31
Entity Filer Category	Accelerated Filer
Document Type	10-Q
Document Period End Date	Sep. 30, 2015
Document Fiscal Year Focus	2,015
Document Fiscal Period Focus	Q3
Amendment Flag	false
Entity Common Stock, Shares Outstanding		30,793,605

Unaudited Condensed Consolidate

Unaudited Condensed Consolidated Balance Sheets - USD ($) $ in Thousands	Sep. 30, 2015	Dec. 31, 2014
Current assets
Cash and cash equivalents	$ 141,940	$ 254,351
Restricted cash	2,314	813
Trade accounts receivable, net of allowance for doubtful accounts of $957 and $679 at September 30, 2015 and December 31, 2014, respectively	61,206	40,875
Unbilled revenue	111,835	97,512
Capitalized incremental direct customer contract costs	21,047	7,633
Deferred tax assets	6,891	6,524
Prepaid expenses and other current assets	14,852	12,613
Assets held for sale	1,423	0
Total current assets	361,508	420,321
Property and equipment, net of accumulated depreciation of $108,636 and $94,976 at September 30, 2015 and December 31, 2014, respectively	51,750	50,458
Goodwill	149,239	114,939
Intangible assets, net	58,279	31,111
Deferred tax assets	766	680
Deposits and other assets	6,840	7,193
Total assets	628,382	624,702
Current liabilities
Accounts payable	2,242	9,250
Accrued capacity payments	130,479	92,332
Accrued payroll and related expenses	18,862	18,446
Accrued expenses and other current liabilities	25,493	28,724
Deferred revenue	36,138	13,738
Liabilities held for sale	477	0
Total current liabilities	213,691	162,490
Convertible senior notes	141,971	138,908
Deferred tax liability	16,878	16,449
Deferred revenue	6,509	5,816
Other liabilities	9,341	8,919
Commitments and contingencies (Note 8)	0	0
Stockholders’ equity
Undesignated preferred stock, $0.001 par value; 5,000,000 shares authorized; no shares issued	0	0
Common stock, $0.001 par value; 50,000,000 shares authorized, 30,830,238 and 29,833,578 shares issued and outstanding at September 30, 2015 and December 31, 2014, respectively	31	30
Additional paid-in capital	374,583	365,855
Accumulated other comprehensive loss	(9,471)	(4,752)
Accumulated deficit	(125,355)	(69,260)
Total EnerNOC, Inc. stockholders’ equity	239,788	291,873
Noncontrolling interest	204	247
Total stockholders’ equity	239,992	292,120
Total liabilities and stockholders’ equity	$ 628,382	$ 624,702

Unaudited Condensed Consolidat3

Unaudited Condensed Consolidated Balance Sheets (Parenthetical) - USD ($) $ in Thousands	Sep. 30, 2015	Dec. 31, 2014
Statement of Financial Position [Abstract]
Trade accounts receivable, net of allowance for doubtful accounts	$ 957	$ 679
Property and equipment, net of accumulated depreciation	$ 108,636	$ 94,976
Undesignated preferred stock:
Par value	$ 0.001	$ 0.001
Shares authorized	5,000,000	5,000,000
Shares issued	0	0
Common Stock:
Par value	$ 0.001	$ 0.001
Shares authorized	50,000,000	50,000,000
Shares issued	30,830,238	29,833,578
Shares outstanding	30,830,238	29,833,578

Unaudited Condensed Consolidat4

Unaudited Condensed Consolidated Statements of Income - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Revenues:
Grid operator	$ 173,374	$ 291,848	$ 238,632	$ 350,592
Utility	27,160	27,741	50,498	50,011
Enterprise	16,790	9,833	51,245	25,382
Total revenues	217,324	329,422	340,375	425,985
Cost of revenues	143,146	168,564	208,645	232,505
Gross profit	74,178	160,858	131,730	193,480
Operating expenses:
Selling and marketing	22,397	18,972	74,563	56,997
General and administrative	26,707	24,472	83,450	72,340
Research and development	6,626	5,260	21,812	15,432
Gain on sale of service line	0	(359)	0	(3,737)
Gain on the sale of assets	0	0	(2,991)	(2,171)
Total operating expenses	55,730	48,345	176,834	138,861
Income (loss) from operations	18,448	112,513	(45,104)	54,619
Other expense, net	(2,814)	(2,224)	(5,766)	(1,276)
Interest expense	(2,253)	(1,523)	(6,785)	(2,576)
Income (loss) before income tax	13,381	108,766	(57,655)	50,767
(Provision for) benefit from income tax	(417)	(12,111)	1,523	(11,950)
Net income (loss)	12,964	96,655	(56,132)	38,817
Net loss attributable to noncontrolling interest	(23)	(18)	(37)	(58)
Net income (loss) attributable to EnerNOC, Inc.	$ 12,987	$ 96,673	$ (56,095)	$ 38,875
Net income (loss) per common share
Basic (in dollars per share)	$ 0.46	$ 3.48	$ (1.98)	$ 1.38
Diluted (in dollars per share)	$ 0.44	$ 3.11	$ (1.98)	$ 1.33
Weighted average number of common shares used in computing net income (loss) per common share
Basic (in shares)	28,507,939	27,795,154	28,282,647	28,075,291
Diluted (in shares)	34,623,574	31,434,164	28,282,647	30,074,187

Unaudited Condensed Consolidat5

Unaudited Condensed Consolidated Statements of Comprehensive Loss - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Statement of Comprehensive Income [Abstract]
Net income (loss)	$ 12,964	$ 96,655	$ (56,132)	$ 38,817
Foreign currency translation adjustments	(2,069)	(1,572)	(4,719)	(678)
Comprehensive income (loss)	10,895	95,083	(60,851)	38,139
Comprehensive loss attributable to noncontrolling interest	(24)	(18)	(43)	(52)
Comprehensive income (loss) attributable to EnerNOC, Inc.	$ 10,919	$ 95,101	$ (60,808)	$ 38,191

Unaudited Condensed Consolidat6

Unaudited Condensed Consolidated Statements of Cash Flows - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014
Cash flows from operating activities
Net income (loss)	$ (56,132)	$ 38,817
Adjustments to reconcile net loss to net cash (used in) provided by operating activities:
Depreciation	17,652	16,414
Amortization of acquired intangible assets	11,607	6,753
Amortization of acquired intangible assets	468	291
Stock-based compensation expense	10,890	12,161
Excess tax benefits from exercise of stock-based awards	0	(219)
Gain on sale of service line	0	(3,737)
Gain on sale of assets	(2,991)	(2,171)
Impairment of property and equipment and definite lived intangible assets	495	856
Unrealized foreign exchange translation loss	6,010	2,417
Deferred income taxes	(2,271)	5,594
Non-cash interest expense	3,791	861
Other, net	79	371
Changes in operating assets and liabilities, net of effects of acquisitions:
Trade accounts receivable	(13,199)	(19,957)
Unbilled revenue	(14,429)	(89,783)
Prepaid expenses and other current assets	(7,353)	(1,524)
Capitalized incremental direct customer contract costs	(12,766)	2,910
Other noncurrent assets	(844)	225
Other noncurrent liabilities	537	(515)
Deferred revenue, current	23,017	(6,709)
Accrued capacity payments	39,367	49,660
Accrued payroll and related expenses	(2,692)	1,466
Accounts payable, accrued expenses and other current liabilities	(19,462)	15,531
Net cash (used in) provided by operating activities	(18,226)	29,712
Cash flows from investing activities
Purchases of property and equipment	(17,724)	(19,248)
Payments made for acquisitions, net of cash acquired	(77,559)	(36,406)
Payments made for investments	0	(2,500)
Proceeds from sale of service line	0	4,275
Proceeds from sale of assets	2,991	2,171
Change in restricted cash and deposits	3,411	(1,349)
Payments made for acquisition of customer contract	0	(403)
Net cash used in investing activities	(88,881)	(53,460)
Cash flows from financing activities
Proceeds from convertible debt offering	400	155,277
Proceeds from exercises of stock options	1,074	1,456
Payments made for buy back of common stock	0	(29,973)
Payments made for employee restricted stock minimum tax withholdings	(3,805)	(5,874)
Excess tax benefit related to exercise of options, restricted stock and restricted stock units	0	219
Net cash (used in) provided by financing activities	(2,331)	121,105
Effects of exchange rate changes on cash and cash equivalents	(2,973)	(331)
Net change in cash and cash equivalents	(112,411)	97,026
Cash and cash equivalents at beginning of period	254,351	149,189
Cash and cash equivalents at end of period	141,940	246,215
Supplemental disclosure of cash flow information
Cash paid for interest	2,993	1,194
Cash paid for income taxes	4,046	1,691
Non-cash financing and investing activities
Issuance of common stock in connection with acquisitions	103	0
Issuance of common stock in satisfaction of bonuses	865	145
Acquisition of property and equipment in accrued expenses	$ 1,940	$ 1,392

Description of Business and Bas

Description of Business and Basis of Presentation	9 Months Ended
	Sep. 30, 2015
Accounting Policies [Abstract]
Description of Business and Basis of Presentation	Description of Business, Basis of Presentation and Summary of Significant Accounting Policies Description of Business EnerNOC, Inc. (the Company) is a leading provider of energy intelligence software (EIS) and related solutions. The Company’s enterprise customers use the Company's Software-as-a-Service (SaaS) solutions to transform how they manage and control energy spend for their organizations, while utilities leverage the Company's SaaS solutions to better engage their customers, deliver savings and consumption reductions to help achieve energy efficiency mandates, manage system peaks and grid constraints, and increase demand for utility-provided products and services. The Company’s EIS and related solutions for utility customers and electric power grid operators also include the demand response solutions and applications, EnerNOC Demand Manager™ and EnerNOC Demand Resource™. EnerNOC Demand Manager is a SaaS application that provides utilities with the underlying technology to manage their demand response programs and secure reliable demand-side resources. EnerNOC Demand Resource is a turnkey demand response resource that matches obligation, in the form of megawatts (MWs) that the Company agrees to deliver to the Company’s utility customers and electric power grid operators, with supply, in the form of MWs that are curtailed from the electric power grid through its arrangements with its enterprise cust omers. Reclassifications The Company has reclassified certain amounts in its consolidated balance sheet as of December 31, 2014 to conform to the consolidated balance sheet presentation as of September 30, 2015. The reclassifications made relate to the merger of various balance sheet captions, specifically (i) the noncurrent portion of capitalized incremental direct customer contract costs was merged into deposits and other assets and (ii) accrued acquisition consideration was merged into other liabilities. Basis of Presentation The accompanying unaudited condensed consolidated financial statements of the Company have been prepared in accordance with accounting principles generally accepted in the United States for interim financial information and with the instructions to Form 10-Q and Rule 10-01 of Regulation S-X. Accordingly, they do not include all of the information and notes required by accounting principles generally accepted in the United States for complete financial statements. All adjustments, which, in the opinion of management, are considered necessary for a fair presentation of the results of operations for the periods shown, are of a normal recurring nature and have been reflected in the condensed consolidated financial statements and accompanying notes. The results of operations for the periods presented are not necessarily indicative of the results expected for the full year or for any future period partially because of the seasonality of the Company’s business. The information included in these condensed consolidated financial statements should be read in conjunction with “Management’s Discussion and Analysis of Financial Condition and Results of Operations” contained in this report and the consolidated financial statements and accompanying notes included in the Company’s Annual Report on Form 10-K for the year ended December 31, 2014, as amended. The condensed consolidated financial statements of the Company include the accounts of its wholly-owned subsidiaries. All significant transactions and balances between the Company and its subsidiaries have been eliminated. The Company owns 60% of EnerNOC Japan K.K, for which it consolidates the operations in accordance with Accounting Standards Codification (ASC) 810, Consolidation (ASC 810). The remaining 40% represents non-controlling interest in the accompanying unaudited condensed consolidated balance sheets and statements of operations. The Company recorded an adjustment in the condensed consolidated statement of operations during the three months ended June 30, 2015 to increase cost of goods sold by approximately $610 related to the recognition of payments owed to enterprise customers enrolled in demand response programs relating to the year ended December 31, 2014. The Company assessed the materiality of the historical misstatements, individually and in aggregate, on its prior annual and quarterly consolidated financial statements and concluded the effect of the error was not material to its consolidated financial statements for any of the periods. Summary of Significant Accounting Policies Use of Estimates in Preparation of Financial Statements The preparation of financial statements in conformity with accounting principles generally accepted in the United States (GAAP) requires management to make estimates and assumptions that affect the amounts reported in the condensed consolidated financial statements and accompanying notes. Significant estimates made by management relate to revenue recognition reserves, allowances for doubtful accounts, valuations and purchase price allocations related to business combinations, including the fair value of intangible assets and accrued acquisition consideration, expected future cash flows used to evaluate the recoverability of long-lived assets, amortization methods and periods, certain accrued expenses and other related charges, stock-based compensation, contingent liabilities, tax reserves and recoverability of the Company’s net deferred tax assets and related valuation allowance. While the Company believes that such estimates are fair when considered in conjunction with the condensed consolidated financial position and results of operations taken as a whole, the actual amounts of such items, when known, will vary from these estimates. Beginning in the third quarter of 2015 the Company changed its U.S. paid time off program from a capped program based on service and employment status to an unlimited time off program. This change in policy resulted in a $2,308 reduction in the Company’s accrued vacation expense that was recorded in the three months ended September 30, 2015. Revenue Recognition The Company recognizes revenues in accordance with ASC 605, Revenue Recognition (ASC 605). The Company's customers include enterprises, utilities and grid operators. The Company derives recurring revenues from the sale of EIS and related solutions. The Company recognizes revenue when it is earned and all of the following criteria are met: persuasive evidence of an arrangement exists, delivery has occurred, the fee is fixed or determinable, and we deem collection to be reasonably assured. The Company maintains a reserve for customer adjustments and allowances as a reduction in revenues. In determining the revenue reserve estimate, the Company relies on historical data and known performance adjustments. These factors, and unanticipated changes in the economic and industry environment, could cause the Company's reserve estimates to differ from actual results. The Company records a provision for estimated customer adjustments and allowances in the same period as the related revenues are recorded. These estimates are based on the specific facts and circumstances of a particular program, analysis of credit memo data, historical customer adjustments, and other known factors. If the data used to calculate these estimates does not properly reflect reserve requirements, then a change in the allowances would be made in the period in which such a determination was made and revenues in that period could be affected. The Company's enterprise revenues from the sales of EIS and related solutions to enterprise customers generally represent ongoing software or service arrangements under which the revenues are recognized ratably over the same period commencing upon delivery of the EIS and related solutions to the enterprise customer. Under certain of its arrangements, a portion of the fees received may be subject to adjustment or refund based on the validation of the energy savings delivered after the implementation is complete. As a result, the Company defers the portion of the fees that are subject to adjustment or refund until such time as the right of adjustment or refund lapses, which is generally upon completion and validation of the implementation. EnerNOC Demand Resource The Company's grid operator revenues and utility revenues primarily reflect demand response revenues from the sale of EnerNOC Demand Resource. During the three and nine months ended September 30, 2015, revenues from grid operators and utilities for EnerNOC Demand Resource were $198,701 and $282,845 , respectively. During the three and nine months ended September 30, 2014, revenues from grid operators and utilities for the EnerNOC Demand Resource solution were $318,629 and $396,051 , respectively. The revenues from EnerNOC Demand Resource primarily consist of capacity and energy payments, including ancillary services payments, as well as payments derived from the effective management of the Company's portfolio of demand response capacity, including the Company's participation in capacity auctions and third-party contracts and ongoing fixed fees for the overall management of utility-sponsored demand response programs. The Company derives revenues from EnerNOC Demand Resource by making demand response capacity available in open market programs and pursuant to contracts that the Company enters into with electric power grid operators and utilities. The Company recognizes revenue from EnerNOC Demand Resource when it has provided verification to the electric power grid operator or utility of its ability to deliver the committed capacity which entitles the Company to payments under the contract or open market program. Committed capacity is generally verified through the results of an actual demand response event or a measurement and verification test. Once the capacity amount has been verified, the revenue is recognized and future revenue becomes fixed or determinable and is recognized monthly until the next demand response event or test. In subsequent verification events, if the Company’s verified capacity is below the previously verified amount, the electric power grid operator or utility customer will reduce future payments based on the adjusted verified capacity amounts. Ongoing demand response revenue recognized between demand response events or tests that are not subject to penalty or customer refund are recognized in revenue. If the revenue is subject to refund and the amount of refund cannot be reliably estimated, the revenue is deferred until the right of refund lapses. EnerNOC Demand Resource energy revenues are recognized when earned. Energy event revenue is deemed to be substantive and represents the culmination of a separate earnings process and is recognized when the energy event is initiated by the electric power grid operator or utility customer and the Company has responded under the terms of the contract or open market program. EnerNOC Demand Resource capacity revenues related to the Company’s participation in the PJM open market program for its Limited demand response product (referred to as the PJM summer-only open market program in prior filings) are being recognized at the end of the four month delivery period of June through September, or during the three months ended September 30 of each year. Because the period during which the Company is required to perform (June through September) is shorter than the period over which payments are received under the program (June through May), a portion of the revenues that have been earned are recorded and accrued as unbilled revenue. Substantially all revenues related to the PJM Limited demand response product are recognized during the three months ended September 30. As a result of the billing period not coinciding with the revenue recognition period, the Company had $110,584 and $96,404 in unbilled revenues from PJM at September 30, 2015 and December 31, 2014, respectively. Two new demand response programs, which we refer to as the PJM Extended program and the PJM Annual program, were introduced in the PJM market beginning in the 2014/2015 delivery year (June 1, 2014-May 31, 2015). Under the PJM Extended program, the delivery period is from June through October and then May in the subsequent calendar year. The revenues and any associated penalties, if any, for underperformance related to participation in the PJM Extended program are separate and distinct from the Company’s participation in other offerings within the PJM open market program. Consistent with the PJM Limited demand response program, the fees paid under this program could potentially be subject to adjustment or refund based on performance during the applicable performance period. Due to the lack of historical performance experience with the PJM Extended program, the Company is unable to reliably estimate the amount of fees potentially subject to adjustment or refund as of the end of September and therefore, revenue from the PJM Extended program is deferred and recognized at the end of the delivery period (i.e., May). Under the PJM Annual program, the delivery period is from June through May of the following year. Consistent with the PJM Limited and PJM Extended programs, to the extent the Company has MW obligation in the PJM Annual program, until the Company is able to reliably estimate the amount of fees potentially subject to adjustment or refund, revenue from the PJM Annual program will be deferred and recognized at the end of the delivery period (i.e., May). However, in the event the Company reduces its MW obligation for a given program to zero through the effective management of its portfolio, including the Company’s participation in PJM incremental auctions, the Company recognizes revenue from such products at the beginning of the delivery year. Historically, all capacity revenues related to the Company's participation in the Western Australia open market have been deferred and recognized upon an emergency event dispatch or the end of the program period on September 30th as the Company was not able to reliably estimate the amount of fees potentially subject to adjustment or refund. As of September 30, 2014, the Company determined that the amount of fees potentially subject to adjustment or refund were reliably estimable and began recognizing revenue ratably over the twelve month program period beginning with the new program year in Western Australia commencing on October 1, 2014. EnerNOC Demand Manager With respect to EnerNOC Demand Manager, the Company generally receives an ongoing fee for overall management of the utility demand response program based on enrolled capacity or enrolled enterprise customers, and recognizes revenues from these fees ratably over the applicable service delivery period commencing upon when the enterprise customers have been enrolled and the contracted services have been delivered. In addition, under this offering the Company may receive additional program start-up and installation fees, which the Company recognizes over the estimated customer relationship period, which is generally the greater of three years or the contract period. Stock-Based Compensation The Company maintains stock-based compensation plans for its employees and outside directors and accounts for stock-based compensation arrangements in accordance with the authoritative guidance, which requires the Company to measure and record compensation expense in its condensed consolidated financial statements using a fair value method. See Note 9 for further information regarding the Company’s stock-based compensation plans. Internal Use Software The Company applies the provisions of ASC 350-40, Internal-Use Software (ASC 350-40), which requires computer software costs associated with internal use software to be expensed as incurred until certain capitalization criteria are met. Internal use software development costs of $2,583 and $1,507 for the three months ended September 30, 2015 and 2014 , respectively, and $6,155 and $4,648 for the nine months ended September 30, 2015 and 2014 , have been capitalized in accordance with ASC 350-40. Capitalized costs are amortized over the assets' estimated useful lives. Amortization of capitalized software development costs was $1,893 and $1,547 for the three months ended September 30, 2015 and 2014 , respectively and $5,288 and $4,573 for the nine months ended September 30, 2015 and 2014 , respectively. Accumulated amortization of capitalized software development costs was $32,891 and $27,603 as of September 30, 2015 and December 31, 2014 , respectively. Cost Method Investments The Company holds investments in privately-held companies of approximately $2,500 and $1,000 as of September 30, 2015 and December 31, 2014, respectively, which are accounted for based on the cost method and are included in deposits and other assets in the accompanying condensed consolidated balance sheets. In August 2014, the Company purchased a convertible promissory note for a purchase price of $1,500 in a privately-held SaaS company that serves businesses seeking an innovative approach to measure and track the positive business impact of engaging employees in sustainability through technology. At the time of the purchase, the Company concluded that this investment should be accounted for as an available-for-sale investment and was classified as such as of December 31, 2014. During the nine months ended September 30, 2015, the note was converted into Series A-1 preferred stock. As the preferred stock does not have a readily determinable fair value it is exempt from the scope of ASC 320, Investments-Debt and Equity Securities, and is thus carried at cost as of September 30, 2015. The Company periodically reviews these investments for impairment. If the Company determines that an other-than-temporary impairment has occurred, it will write-down the investment to its fair value. For the three and nine months ended September 30, 2015, the Company determined that the fair value of its cost method investments was not estimable and to do so would be impractical as there were no identified events or changes in circumstances that had a significant adverse effect on the fair value of the investments. Subsequent Events Consideration The Company considers events or transactions that occur after the balance sheet date but prior to the issuance of the financial statements to provide additional evidence relative to certain estimates or to identify matters that require additional disclosure. Subsequent events have been evaluated as required.

Acquisition

Acquisition	9 Months Ended
	Sep. 30, 2015
Business Combinations [Abstract]
Acquisition	Acquisition World Energy Solutions, Inc. On January 5, 2015, the Company completed the acquisition of World Energy Solutions, Inc., or World Energy, an energy management software and services firm located in Worcester, Massachusetts that helps enterprises to simplify the energy procurement process through a suite of SaaS tools. The Company believes that the acquisition and integration of World Energy’s software into its EIS platform will help deliver more value to its enterprise customers through enhanced technology-enabled capabilities to manage the energy procurement process. The Company concluded that this acquisition represented a business combination under the provisions of ASC 805, Business Combinations (ASC 805), but has concluded that it did not represent a material business combination, and therefore, no pro forma financial information is required to be presented. Subsequent to the acquisition date, the Company’s results of operations include the results of operations of World Energy. The Company acquired World Energy for a purchase price of $5.50 per share of World Energy's outstanding common stock and the assumption of debt for an aggregate purchase price of $79,913 , or $77,211 net of $2,702 in acquired cash. The Company paid cash of $68,538 for shares outstanding and $9,468 to repay debt. In addition, the Company was required to exchange and replace the outstanding share based awards of World Energy on the acquisition date. The Company cash settled the outstanding restricted stock awards and vested stock options for which the per share exercise price was equal to or less than $5.50 per share, and issued replacement awards for World Energy vested, out-of-the-money stock options and non-vested stock options for a total value of $3,027 . Of this amount, $1,849 was determined to be purchase price consideration and $1,178 was determined to be post combination stock-based compensation expense $443 was recognized immediately as expense upon the close of the transaction as there was no remaining service period, with the remaining expense to be recognized over a period of 2.3 years ). In addition, the Company paid $58 for outstanding warrants. Transaction costs of $367 related to World Energy were expensed as incurred and are included in general and administrative expenses in the Company’s unaudited condensed consolidated statements of operations. The Company allocated the purchase price to the net tangible assets and intangible assets based upon their fair values at January 5, 2015. The difference between the aggregate purchase price and the fair value of assets acquired and liabilities assumed was allocated to goodwill, none of which is deductible for tax purposes. The Company's acquired identifiable intangible assets include $29,160 of customer relationships and $12,240 of developed technology. As of the date of acquisition, the Company determined that there was no in-process research and development as the ongoing research and development efforts were nominal and related to routine, on-going maintenance efforts. The Company amortizes these acquired intangible assets over their estimated useful lives using a method that is based on estimated future cash flows as the Company believes this will approximate the pattern in which the economic benefits of the assets will be utilized. As of September 30, 2015 , the acquired intangible assets will be amortized as follows: customer relationships (backlog) of 4.2 years ; customer relationships (contract renewals) of 14.2 years and developed technology of 9.2 years . The following table summarizes the purchase consideration paid for World Energy: Purchase consideration: Cash paid for stock, stock awards and warrants $ 70,445 Repayment of debt 9,468 Fair value of consideration transferred $ 79,913 As of the filing date of this Quarterly Report on Form 10-Q, the Company remains in the process of valuing the assets acquired and liabilities assumed of World Energy’s business, including accounts receivable and other liabilities. Cash $ 2,702 Accounts receivable (1) 8,946 Prepaid expenses and other current assets 1,596 Property and equipment 449 Identified intangible assets 41,400 Goodwill 39,560 Accounts payable, accrued expenses and other liabilities (1) (12,247 ) Deferred revenue (320 ) Deferred tax liabilities, net (2,173 ) Total $ 79,913 (1) During the nine months ended September 30, 2015, the Company recorded an acquisition accounting adjustment of $391 to reduce accounts receivable and a $300 adjustment to reduce accrued expenses and other liabilities. The acquisition accounting is not complete and additional information that existed at the acquisition date may become known to the Company during the fourth quarter of 2015. World Energy Efficiency Services - Assets and liabilities held for sale The acquisition of World Energy included the World Energy Efficiency Services business (WEES), which provides comprehensive, turnkey direct install energy efficiency services in New England. As of the acquisition date of January 5, 2015, the Company committed to a plan to sell WEES. Based on the Company’s evaluation of the assets held for sale criteria under ASC 360-10, Impairment and Disposal of Long-Lived Assets , the Company concluded all of the criteria were met and that the assets and liabilities of WEES that were expected to be sold should be classified as held for sale as of January 5, 2015. A definitive asset purchase agreement was executed on July 31, 2015 and the sale of WEES subsequently closed on October 16, 2015. The held for sale balances relate to operational assets and liabilities associated with in-progress contracts, and separately identifiable intangible assets, including customer relationships and developed technology that were acquired in connection with the World Energy acquisition and specifically relate to WEES. Because the Company has concluded that WEES meets the definition of a business in accordance with ASC 805, included in assets held for sale is the allocated goodwill of WEES. The following table summarizes the assets and liabilities held for sale as of September 30, 2015 : As of September 30, 2015 Goodwill $ 751 Inventories 623 Fixed assets 49 Assets held for sale $ 1,423 Accounts payable $ (422 ) Deferred revenue (55 ) Liabilities held for sale $ (477 ) The Company has concluded that the sale of WEES does not meet the criteria of discontinued operations under ASC 205-20, Discontinued Operations, because it does not represent a strategic shift that had a major effect on the Company's operations and financial results and, therefore, the results of operations of WEES have not been presented as discontinued operations in the Company’s unaudited condensed consolidated statement of operations for the three and nine months ended September 30, 2015 .

Intangible Assets

Intangible Assets	9 Months Ended
	Sep. 30, 2015
Goodwill and Intangible Assets Disclosure [Abstract]
Intangible Assets	Intangible Assets The following table provides the gross carrying amount and related accumulated amortization of the Company's definite-lived intangible assets as of September 30, 2015 and December 31, 2014 : As of September 30, 2015 As of December 31, 2014 Weighted Average Amortization Period (in years) Gross Carrying Amount Accumulated Amortization Gross Carrying Amount Accumulated Amortization Customer relationships 6.86 $ 60,715 $ (23,527 ) $ 37,516 $ (19,725 ) Customer contracts 1.33 7,896 (6,398 ) 4,912 (3,618 ) Employment and non-compete agreements 0.94 3,091 (2,174 ) 3,198 (1,821 ) Software 0.00 170 (170 ) 120 (120 ) Developed technology 6.36 24,561 (6,063 ) 13,615 (3,407 ) Trade name 0.25 1,097 (1,002 ) 1,124 (777 ) Patents 4.38 180 (97 ) 180 (86 ) Total $ 97,710 $ (39,431 ) $ 60,665 $ (29,554 ) Amortization expense related to definite-lived intangible assets amounted to $3,662 and $2,391 for the three months ended September 30, 2015 and 2014 , respectively and $11,607 and $6,753 for the nine months ended September 30, 2015 and 2014 , respectively. Amortization expense for acquired developed technology, which was $923 and $515 for the three months ended September 30, 2015 and 2014 , respectively, and $2,848 and $1,482 for the nine months ended September 30, 2015 and 2014 , respectively is included in cost of revenues in the unaudited condensed consolidated statements of operations. Amortization expense for all other intangible assets is included as a component of operating expenses in the unaudited condensed consolidated statements of operations. The definite-lived intangible asset lives range from 1 to 15 years and the weighted average remaining life was 6 years at September 30, 2015 . Amortization expense is estimated to be approximately $2,945 , $10,943 , $9,175 , $7,172 , $5,893 and $22,151 for the three months ending December 31, 2015 , and years ending 2016, 2017, 2018, 2019 and through the remaining years of the asset's useful life, respectively.

Goodwill

Goodwill	9 Months Ended
	Sep. 30, 2015
Goodwill and Intangible Assets Disclosure [Abstract]
Goodwill	Goodwill The Company accounts for goodwill in accordance with ASC 350, Intangibles-Goodwill and Other (ASC 350), which requires that goodwill is not amortized, but is subject to an annual impairment test. There was no impairment of goodwill as a result of the annual impairment test analysis completed during the fourth quarter of 2014. There were no indicators of impairment during the nine months ended September 30, 2015. The following table shows the change of the carrying amount of goodwill from December 31, 2014 to September 30, 2015 : Balance at December 31, 2014 $ 114,939 Foreign currency translation impact (4,769 ) Acquisition of World Energy (Note 2) 39,560 Assets held for sale (751 ) Current period purchase price adjustment (1) 260 Balance at September 30, 2015 $ 149,239 (1) The current period purchase price adjustment relates to the December 2014 acquisition of Pulse Energy, Inc. for which the Company adjusted certain estimates associated with the acquired deferred tax assets.

Net Income (Loss) Per Share

Net Income (Loss) Per Share	9 Months Ended
	Sep. 30, 2015
Earnings Per Share [Abstract]
Net Income (Loss) Per Share	Net Income (Loss) Per Share Computation of basic and diluted net income (loss) per share is as follows (in thousands, except per share information): Three Months Ended Nine Months Ended Numerator: 2015 2014 2015 2014 Net income (loss) for basic earnings per share 12,987 96,673 (56,095 ) 38,875 ADD: Interest expense related to convertible notes 2,118 980 6,251 980 Net income (loss) for diluted earnings per share 15,105 97,653 (49,844 ) 39,855 Denominator: Basic weighted average common shares outstanding 28,507,939 27,795,154 28,282,647 28,075,291 Weighted average common stock equivalents 340,707 877,088 — 1,068,138 Incremental shares from assumed conversion of convertible notes 5,774,928 2,761,922 — 930,758 Diluted weighted average common shares outstanding 34,623,574 31,434,164 28,282,647 30,074,187 Basic net income (loss) per share $ 0.46 $ 3.48 $ (1.98 ) $ 1.38 Diluted net income (loss) per share $ 0.44 $ 3.11 $ (1.98 ) $ 1.33 Anti-dilutive shares relate to: Stock options 473,848 1,667 418,024 4,602 Nonvested restricted stock 2,285,100 91,755 2,228,630 384,031 Restricted stock units 72,261 7,144 72,261 10,076 Convertible debt — — 5,774,928 — In reporting periods in which the Company reports net loss, anti-dilutive shares consist of the impact of those number of shares that would have been dilutive had the Company had net income plus the number of common stock equivalents that would have been anti-dilutive had the Company had net income. In those reporting periods in which the Company reports net income, anti-dilutive shares consist of those common stock equivalents that have either an exercise price above the average stock price for the period or the common stock equivalents’ related average unrecognized stock compensation expense is sufficient to “buy back” the entire amount of shares. On May 27, 2015, the Company received stockholder approval at its annual meeting of stockholders (the Annual Meeting) to elect to settle conversions of $160,000 aggregate principal amount of its 2.25% convertible senior notes due August 15, 2019 (the Notes) by paying or delivering, as the case may be, cash, shares of common stock or a combination of cash and shares of common stock. Under the applicable accounting standards, if an entity controls the means of settlement and past experience or a stated policy provides a reasonable basis to believe that the Notes will be partially or wholly settled in cash, the shares issuable upon conversion of convertible debt instruments may be excluded from the calculation of diluted earnings per share. The Company used the "if-converted" method to calculate diluted earnings per share for the three months ended September 30, 2015 as a result of an uncertainty as to its ability to reliably estimate cash flows into 2019 that would support repayment in cash. For the nine months ended September 30, 2015, the convertible debt is not assumed to be converted as the impact is anti-dilutive. See Note 7 for further information regarding the Company's convertible debt. The Company excludes the shares issued in connection with restricted stock awards from the calculation of basic weighted average common shares outstanding until such time as those shares vest. In addition, with respect to restricted stock awards that vest based on achievement of performance conditions, because performance conditions are considered contingencies under ASC 260, Earnings Per Share , the criteria for contingent shares must first be applied before determining the dilutive effect of these types of share-based payments. Prior to the end of the contingency period (i.e., before the performance conditions have been satisfied), the number of contingently issuable common shares to be included in diluted weighted average common shares outstanding should be based on the number of common shares, if any, that would be issuable under the terms of the arrangement if the end of the reporting period were the end of the contingency period (e.g., the number of shares that would be issuable based on current performance criteria) assuming the result would be dilutive. In connection with certain of the Company’s business combinations, the Company issued common shares that were held in escrow upon closing of the applicable business combination. The Company excludes shares held in escrow from the calculation of basic weighted average common shares outstanding where the release of such shares is contingent upon an event and not solely subject to the passage of time. As of September 30, 2015 , the Company had 87,483 shares of common stock held in escrow. The Company includes the 254,654 shares related to a component of the deferred purchase price consideration from the acquisition of M2M Communications Corporation in both the basic and diluted weighted average common shares outstanding amounts as the shares are not subject to adjustment and the issuance of such shares is not subject to any contingency.

Fair Value Measurements

Fair Value Measurements	9 Months Ended
	Sep. 30, 2015
Fair Value Disclosures [Abstract]
Fair Value Measurements	Fair Value Measurements The Company’s financial instruments mainly consist of cash and cash equivalents, restricted cash, accounts receivable and accounts payable. The carrying amounts of these financial instruments approximate their respective fair value due to their short-term nature. The Company has $2,500 of investments recorded at cost as of September 30, 2015. The Company has $160,000 of convertible debt outstanding (Note 7) as of September 30, 2015 . The fair value of the convertible debt was approximately $112,800 and $133,392 as of September 30, 2015 and December 31, 2014 and was determined based on the quoted market price and is classified as Level 1 measurement. The table below presents the balances of assets and liabilities measured at fair value on a recurring basis at September 30, 2015 and December 31, 2014 : Totals Quoted Prices in Significant Other (Level 2) Unobservable Inputs (Level 3) Fair Value Measurement at September 30, 2015 Assets: Money market funds (1) $ 113,745 $ 113,745 $ — $ — Liabilities: Contingent purchase price consideration (2) 803 — — 803 Fair Value Measurement at December 31, 2014 Assets: Money market funds (1) $ 225,815 $ 225,815 $ — $ — Liabilities: Contingent purchase price consideration (2) 649 — — 649 (1) The money market funds balance included in cash and cash equivalents represents the only asset that the Company measures and records at fair value on a recurring basis. These money market funds represent excess operating cash that is invested daily into an overnight investment account. (2) Accrued contingent purchase price consideration relates to the Company’s acquisitions of Activation Energy DSU Limited (Activation Energy) and Entelios AG (Entelios) in February 2014. As of September 30, 2015 , approximately $700 associated with the Activation Energy acquisition has been reflected in accrued expense and other current liabilities in the condensed consolidated balance sheet. The additional $103 relates to the Entelios earn-out, which is reflected in other liabilities in the condensed consolidated balance sheet. As of December 31, 2014, approximately $312 was recorded in accrued expense and other current liabilities, while the remaining $337 was recorded in other liabilities in the condensed consolidated balance sheet. The following is a rollforward of the Level 3 assets and liabilities from January 1, 2015 through September 30, 2015 : Liabilities Balance January 1, 2015 $ 649 Cash payment during the period (277 ) Increase due to change in assumptions and present value accretion 468 Change due to movement in foreign exchange rates (37 ) Balance September 30, 2015 $ 803

Borrowings and Credit Arrangeme

Borrowings and Credit Arrangements	9 Months Ended
	Sep. 30, 2015
Debt Disclosure [Abstract]
Borrowings and Credit Arrangements	Borrowings and Credit Arrangements Credit Agreement On August 11, 2014, the Company entered into a $30,000 senior secured revolving credit facility, the full amount of which may be available for issuances of letters of credit, pursuant to a loan and security agreement (the 2014 credit facility) with Silicon Valley Bank (SVB), which was subsequently amended on October 23, 2014. The 2014 credit facility is subject to continued covenant compliance and borrowing base requirements. As of September 30, 2015 , the Company was in compliance with all of its covenants under the 2014 credit facility. On August 6, 2015, the Company and SVB entered into a second amendment to the 2014 credit facility to extend the termination date from August 11, 2015 to August 9, 2016. The Company believes that it is reasonably assured that it will comply with the covenants of the 2014 credit facility through its expiration date of August 9, 2016. As of September 30, 2015 , the Company had no borrowings, but had outstanding letters of credit totaling $22,599 under the 2014 credit facility. As of September 30, 2015 , the Company had $7,401 available under the 2014 credit facility for future borrowings or issuances of additional letters of credit. Convertible Notes On August 12, 2014, the Company entered into a purchase agreement with Morgan Stanley & Co. LLC relating to the Company’s sale of $160,000 aggregate principal amount of 2.25% convertible senior notes due August 15, 2019 (the Notes). The Notes include customary terms and covenants, including certain events of default after which the Notes may be declared or become due and payable immediately. The Notes are convertible at an initial conversion rate of 36.0933 shares of the common stock per $1,000 principal amount of Notes. However, because the Company received approval at the Annual Meeting, it may elect to settle conversions of Notes by paying or delivering, as the case may be, cash, shares of common stock or a combination of cash and shares of common stock. The conversion rate will be subject to adjustment in some events, but will not be adjusted for any accrued and unpaid interest. The Company has concluded that ASC 470, Debt, applies to the Notes and accordingly, the Company is required to account for the liability and equity components of its Notes separately to reflect its nonconvertible debt borrowing rate. The estimated fair value of the liability component at issuance of $137,430 was determined using a discounted cash flow technique. The excess of the gross proceeds received over the estimated fair value of the liability component totaling $22,570 has been allocated to the conversion feature (equity component) with a corresponding offset recognized as a discount to reduce the net carrying value of the Notes. The discount is being amortized to interest expense over a five year period ending August 15, 2019 (the expected life of the liability component) using the effective interest method. In addition, transaction costs are required to be allocated to the liability and equity components based on their relative percentages. The applicable transaction costs allocated to the liability and equity components at issuance were $4,056 and $666 , respectively. During the three months ended September 30, 2015, the Company was reimbursed for transaction costs totaling $400 which was allocated to the liability component. The transaction costs allocated to the liability represent debt issuance costs which are recorded as an asset and are being amortized to interest expense on a straight-line basis over a five year period. As of September 30, 2015 , $710 and $2,285 of deferred issuance costs are included in prepaid expenses and other current assets and deposits and other assets, respectively, in the Company’s unaudited condensed consolidated balance sheet. Interest expense under the Notes is as follows: Three Months Ended Nine Months Ended 2015 2014 2015 2014 Accretion of debt discount $ 1,043 $ 474 $ 3,063 $ 474 Amortization of deferred financing costs 175 76 508 76 Non-cash interest expense 1,218 550 3,571 550 2.25% accrued interest 900 430 2,680 430 Total interest expense from Notes $ 2,118 $ 980 $ 6,251 $ 980 Based on the Company’s evaluation of the Notes in accordance with ASC 815-40, Contracts in Entity’s Own Equity , the Company determined that the Notes contain a single embedded derivative, comprised of the contingent interest feature related to timely SEC filing failure, which requires bifurcation as the feature is not clearly and closely related to the host instrument. The Company has determined that the value of this embedded derivative was nominal as of the date of issuance and as of September 30, 2015 .

Commitments and Contingencies

Commitments and Contingencies	9 Months Ended
	Sep. 30, 2015
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies	Commitments and Contingencies The Company leases certain office space under various operating leases. In addition to rent, the leases require the Company to pay for taxes, insurance, maintenance and other operating expenses. Certain of these leases contain stated escalation clauses while others contain renewal options. The Company recognizes rent expense on a straight-line basis over the term of the lease, excluding renewal periods, unless renewal of the lease is reasonably assured. As of September 30, 2015 , the Company was contingently liable under outstanding letters of credit for $22,599 . As of September 30, 2015 and December 31, 2014 , the Company had restricted cash balances of $2,314 and $813 , respectively, which primarily related to cash utilized to collateralize certain demand response programs. These amounts are included in prepaid expenses and other current assets and deposits and other assets, respectively, in the unaudited condensed consolidated balance sheet. The Company is subject to performance guarantee requirements under certain utility and electric power grid operator customer contracts and open market bidding program participation rules, which may be secured by cash or letters of credit. Performance guarantees as of September 30, 2015 were $20,410 and included deposits held by certain customers of $47 at September 30, 2015 . These amounts primarily represent up-front payments required by utility and electric power grid operator customers as a condition of participation in certain demand response programs and to ensure that the Company will deliver its committed capacity amounts in those programs. If the Company fails to meet its minimum committed capacity requirements, a portion or all of the deposits may be forfeited. The Company assessed the probability of default under these customer contracts and open market bidding programs and has determined the likelihood of default and loss of deposits to be remote. In addition, under certain utility and electric power grid operator customer contracts, if the Company does not achieve the required performance guarantee requirements, the customer can terminate the arrangement and the Company would potentially be subject to termination penalties. Under these arrangements, the Company defers all fees received up to the amount of the potential termination penalty until the Company has concluded that it can reliably determine that the potential termination penalty will not be incurred or the termination penalty lapses. As of September 30, 2015 , the Company had $600 in deferred fees for these arrangements which were included in deferred revenues. As of September 30, 2015 , the maximum termination penalty to which the Company could be subject under these arrangements, which the Company has deemed not probable of being incurred, was approximately $7,422 . On May 23, 2014, the United States Court of Appeals for the D.C. Circuit held in EPSA v. FERC that FERC did not have jurisdiction under the Federal Power Act to issue FERC Order 745, an order that required, among other things, that economic demand response resources participating in the wholesale energy markets administered by electric power grid operators, such as PJM, be paid the locational marginal price of energy. See Part I-Item IA under the heading “Risk Factors” in the Company’s Annual Report on Form 10-K for the year ended December 31, 2014, as amended, for further information regarding EPSA v. FERC. FERC, the Company and a number of other parties filed petitions for a writ of certiorari in the U.S. Supreme Court on January 15, 2015. On May 4, 2015, the U.S. Supreme Court granted petitioners’ writs of certiorari and oral arguments were heard on October 14, 2015. Order 745 remains in effect per the Court’s stay pending the issuance of a decision by the U.S. Supreme Court. Pursuant to the Federal Power Act, Order 745 was implemented “subject to refund,” which means that FERC retained the discretion to order refunds, if appropriate, of revenues associated with implementation of Order 745. The “subject to refund” requirement does not require refund, and given FERC’s past treatment of its refund cases, the Company believes that the likelihood of refunds actually being required is not significant. The Company notes that with respect to the historical fees received from participation in programs that were impacted by Order 745, that Order 745 was effective and binding and that the Company delivered its service in accordance with the applicable market and program tariffs and manuals. As a result, the Company has concluded that the historical revenue recognition was appropriate and that the potential risk of refund as a result of the May 23, 2014 Court ruling on Order 745 should be evaluated as a potential contingent loss as a result of this event in accordance with ASC 450, Contingencies . Based on the Company’s assessment of this matter, it has determined that a loss is not currently probable and as a result, no loss accrual is currently recorded under ASC 450. However, the Company has concluded that it is reasonably possible that the Company may incur a loss and the potential range of loss would be the fees received under the program, which is approximately $20,100 . The Company has determined that due to the potential risk of refund, all fees received prospectively from continued participation after May 23, 2014 in wholesale energy market demand response programs implemented pursuant to Order 745 and administered by a RTO or ISO will be deferred until such time as the fees are either refunded or become no longer subject to refund or adjustment. Subsequent to May 23, 2014 through September 30, 2015 , the Company has received and deferred $2,772 of fees related to these programs. The Company is currently involved in an ongoing matter related to a review of certain services provided under a contractual arrangement with an enterprise customer. This matter is in initial stages and no lawsuit has currently been filed. The Company does not currently believe it is probable that a loss has been incurred and therefore, no amounts have been accrued related to this matter. However, the Company has determined that it is reasonably possible that it may incur a loss related to this matter. The potential amount of such a loss is not currently estimable because the matter is at an early stage and involves unresolved questions of fact.

Stockholders' Equity

Stockholders' Equity	9 Months Ended
	Sep. 30, 2015
Equity [Abstract]
Stockholders' Equity	Stockholders’ Equity 2014 Long-Term Incentive Plan On May 29, 2014, the Company’s stockholders approved the EnerNOC, Inc. 2014 Long-Term Incentive Plan (the 2014 Plan), which was amended by the Company’s stockholders at the Annual Meeting held on May 27, 2015 to increase the number of shares of common stock authorized for issuance under the 2014 Plan by 1,700,000 shares. As of September 30, 2015 , 2,580,300 shares were available for future grant under the 2014 Plan. World Energy Solutions, Inc. 2006 Stock Incentive Plan In connection with the Company’s acquisition of World Energy in January 2015, the Company assumed the World Energy Solutions, Inc. 2006 Stock Incentive Plan (the World Energy Plan). As a result of the assumption, incentive and nonstatutory stock options or stock purchase rights may be granted under the World Energy Plan to employees of the Company who were employees of World Energy prior to January 5, 2015 or were hired by the Company after January 5, 2015. At September 30, 2015 , 94,517 stock-based awards were available for future grants. No awards may be granted under the World Energy Plan after the completion of ten years from August 25, 2006, which is the date on which the World Energy Plan was adopted by the World Energy Board, but awards previously granted may extend beyond that date. Share Repurchase Program and Tax Withholding Obligations On August 11, 2014, the Company’s Board of Directors authorized the repurchase of up to $50,000 of the Company’s common stock during the period from August 11, 2014 through August 8, 2015 (the 2014 Repurchase Program). The Company used $29,975 of the net proceeds from its Notes offering to repurchase 1,514,552 shares of its common stock at a purchase price of $19.79 per share, which was the closing price of the Common Stock on The NASDAQ Global Select Market on August 12, 2014. On August 6, 2015, the Company's Board of Directors approved a new share repurchase program, effective upon the expiration of the Company’s 2014 Repurchase Program on August 8, 2015, that will enable the Company to repurchase up to $50,000 of the Company’s common stock during the period from August 9, 2015 to August 9, 2016 (the 2015 Repurchase Program). Repurchases under the Company’s 2015 Repurchase Program are expected to be made periodically on the open market as market and business conditions warrant, or under a Rule 10b5-1 plan. During the three and nine months ended September 30, 2015 , the Company did not make any repurchases of its common stock under the 2014 Repurchase Program or the 2015 Repurchase Program. The Company withheld 68,367 and 311,244 shares of its common stock during the three and nine months ended September 30, 2015 to satisfy employee minimum statutory income tax withholding obligations in connection with the vesting of restricted stock and restricted stock units under its equity incentive plans, which the Company pays in cash to the appropriate taxing authorities on behalf of its employees. All withheld shares became immediately available for future issuance under the 2014 Plan and the World Energy Plan. Stock-Based Compensation The Company grants share-based awards to employees, non-employees, members of the board and advisory board members. The Company accounts for grants of stock-based compensation in accordance with ASC 718, Stock Compensation (ASC 718). The Company accounts for share-based awards granted to non-employees in accordance with ASC 505-50, Equity Based Payments to Non-Employees , which results in the Company continuing to re-measure the fair value of the non-employee share-based awards until such time as the awards vest. All share-based awards granted, including grants of stock options, restricted stock and restricted stock units, are recognized in the statement of operations based on their fair value as of the date of grant. All shares underlying awards of restricted stock are restricted in that they are not transferable until they vest. Restricted stock typically vests ratably over a four year period from the date of issuance, with certain exceptions. The fair value of restricted stock upon which vesting is solely service-based is expensed ratably over the vesting period. With respect to restricted stock where vesting contains certain performance-based vesting conditions, the fair value is expensed based on the accelerated attribution method as prescribed by ASC 718, over the vesting period. With the exception of certain executives whose employment agreements provide for continued vesting in certain circumstances upon departure, if the employee who received the restricted stock leaves the Company prior to the vesting date for any reason, the shares of restricted stock will be forfeited and returned to the Company. Stock-based compensation expense recorded in the unaudited condensed consolidated statements of operations was as follows: Three Months Ended September 30, Nine Months Ended September 30, 2015 2014 2015 2014 Selling and marketing expenses $ 1,243 $ 1,512 $ 3,194 $ 4,077 General and administrative expenses 2,061 2,262 7,187 7,066 Research and development expenses 351 361 1,004 1,018 Total stock-based compensation expense (1) $ 3,655 $ 4,135 $ 11,385 $ 12,161 (1) Stock-based compensation expense for the three and nine months ended September 30, 2015 include $2 and $495 , respectively, related to the acquisition of World Energy that was settled with the equivalent cash payments. In June 2015, the Company entered into a separation agreement with a former employee. The Company recorded a reversal of previously recognized stock-based compensation expense during the nine months ended September 30, 2015 in the amount of $834 related to the cancellation of non-vested awards upon termination. Stock-based compensation expense related to share-based awards granted to non-employees was not material for the three and nine months ended September 30, 2015 and 2014 . The Company recognized an income tax benefit of $219 from stock-based compensation arrangements during the three and nine months ended September 30, 2014. The Company did not recognize an income tax benefit from stock-based compensation arrangements during the three and nine months ended September 30, 2015 . No material stock-based compensation expense was capitalized during the three and nine months ended September 30, 2015 and 2014 . The Company’s chief executive officer is required to receive his performance-based bonus, if achieved, in shares of the Company's common stock. The Company recorded this amount as stock-based compensation expense ratably over the applicable performance and service period in accordance with ASC 718. During the three and nine months ended September 30, 2015 , the Company recorded $128 and $380 of stock-based compensation expense related to this performance based bonus. During the three and nine months ended September 30, 2014, the Company recorded $129 and $382 of stock-based compensation expense related to this performance based bonus. The EnerNOC, Inc. Amended and Restated 2003 Stock Option and Incentive Plan, the Amended and Restated 2007 Employee, Director and Consultant Stock Plan, the 2014 Plan, and the World Energy Plan (collectively, the Plans) provide for the grant of incentive stock options, nonqualified stock options, restricted and unrestricted stock awards and other stock-based awards to eligible employees, directors and consultants of the Company. Options granted under the Plans are exercisable for a period determined by the Company, but in no event longer than ten years from the date of the grant. Option awards are generally granted with an exercise price equal to the market price of the Company’s common stock on the date of grant. Stock option awards, restricted stock awards and restricted stock unit awards generally vest ratably over four years , with certain exceptions. During the nine months ended September 30, 2015 and 2014 , the Company issued 72,926 and 6,632 shares of its common stock, respectively, to certain executives to satisfy a portion of the Company’s bonus obligations to those individuals. Stock Options The following is a summary of the Company’s stock option activity during the nine months ended September 30, 2015 : Nine Months Ended September 30, 2015 Number of Shares Underlying Options Exercise Price Per Share Weighted- Average Exercise Price Per Share Aggregate Intrinsic Value Outstanding at December 31, 2014 725,578 $0.35 - $43.38 $ 18.01 $ 2,978 (2) Granted 78,413 10.99 Exercised (109,617 ) 9.80 771 (3) Canceled (57,624 ) 16.60 Outstanding at September 30, 2015 636,750 $0.51 - $43.38 $ 18.69 $ 933 (4) Weighted average remaining contractual life in years: 2.2 Exercisable at end of period 603,208 $0.51 - $43.38 $ 19.06 $ 932 (4) Weighted average remaining contractual life in years: 2.1 Vested or expected to vest at September 30, 2015 (1) 634,234 $0.51 - $43.38 $ 18.69 $ 933 (4) (1) This represents the number of vested options as of September 30, 2015 plus the number of non-vested options expected to vest as of September 30, 2015 based on a 7.5% forfeiture rate. (2) The aggregate intrinsic value was calculated based on the positive difference between the estimated fair value of the Company’s common stock on December 31, 2014 of $15.45 and the weighted-average exercise price of the underlying options. (3) The aggregate intrinsic value was calculated based on the difference between the fair value of the Company’s common stock on the applicable exercise dates and the weighted-average exercise price of the underlying options. (4) The aggregate intrinsic value was calculated based on the positive difference between the estimated fair value of the Company’s common stock on September 30, 2015 of $7.90 and the weighted-average exercise price of the underlying options. The weighted average fair value per share of options granted during the nine months ended September 30, 2015 was $9.92 . As of September 30, 2015 , all 636,467 options were held by employees and directors of the Company and 283 option were held by a consultant. As of September 30, 2015 , the Company had $461 of unrecognized stock-based compensation expense, which is expected to be recognized over a weighted average period of 1.6 years. Restricted Stock The following table summarizes the Company’s restricted stock activity during the nine months ended September 30, 2015 : Number of Shares Weighted Average Grant Date Fair Value Per Share Nonvested at December 31, 2014 2,170,267 $ 17.18 Granted 1,439,283 10.98 Vested (834,269 ) 16.13 Cancelled (317,526 ) 15.67 Nonvested at September 30, 2015 2,457,755 $ 14.60 For non-vested restricted stock subject to service-based vesting conditions outstanding as of September 30, 2015 , the Company had $23,427 of unrecognized stock-based compensation expense, which is expected to be recognized over a weighted average period of 2.7 years. For non-vested restricted stock subject to performance-based vesting conditions outstanding that were probable of vesting as of September 30, 2015 , which represents all of the outstanding non-vested restricted stock subject to performance-based vesting conditions, the Company had $2,075 of unrecognized stock-based compensation expense, which is expected to be recognized over a weighted average period of 1.4 years. In February 2015, the Company entered into a separation agreement with a former employee, which changed the employee’s status to non-employee consultant as of July 1, 2015 and provided for the vesting of 12,514 shares of previously non-vested restricted stock, to continue to vest through January 2, 2016, as long as the individual continues to serve as a consultant through the date of the applicable vesting. Through the non-employee consultation period, the restricted stock will be fair valued at the end of each reporting period, with changes in fair value being recorded to the consolidated statement of operations. Restricted Stock Units The following table summarizes the Company’s restricted stock unit activity during the nine months ended September 30, 2015 : Number of Shares Weighted Average Grant Date Fair Value Per Share Nonvested at December 31, 2014 256,872 $ 20.08 Granted 69,950 10.59 Vested (4,939 ) 19.64 Cancelled (39,266 ) 19.00 Nonvested at September 30, 2015 282,617 $ 17.84 During the year ended December 31, 2014, the Company granted 250,382 shares of non-vested restricted stock units that contain performance-based vesting conditions to certain non-executive German employees in connection with its acquisition of Entelios. Vesting would be triggered for these shares if the employee remained employed with the Company and if certain earnings targets were met in 2014, 2015, and 2016. As of September 30, 2015 , the Company has determined that the earnings targets were not probable of being met, and thus the awards have not been deemed probable of vesting. For non-vested restricted stock units subject to service-based vesting conditions outstanding as of September 30, 2015 , the Company had $631 of unrecognized stock-based compensation expense, which is expected to be recognized over a weighted average period of 3.1 years. For non-vested restricted stock units subject to outstanding performance-based vesting conditions that were not probable of vesting at September 30, 2015 , the Company had $4,220 of unrecognized stock-based compensation expense. If and when any additional portion of these non-vested restricted stock units are deemed probable to vest, the Company will reflect the effect of the change in estimate in the period of change by recording a cumulative catch-up adjustment to retroactively apply the new estimate.

Income Taxes

Income Taxes	9 Months Ended
	Sep. 30, 2015
Income Tax Disclosure [Abstract]
Income Taxes	Income Taxes Each interim period is considered an integral part of the annual period and tax expense is measured using an estimated annual effective tax rate. An enterprise is required, at the end of each interim reporting period, to make its best estimate of the effective tax rate for the full fiscal year and use that rate to provide for income taxes on a current year-to-date basis. However, if an enterprise is unable to make a reliable estimate of its annual effective tax rate, the actual effective tax rate for the year-to-date period may be the best estimate of the annual effective tax rate. For the nine month period ended September 30, 2015, the Company determined that it was able to reliably estimate its annual effective tax rate in all jurisdictions in which it operates. The Company recorded a $417 tax expense and $1,523 tax benefit for the three month and nine month periods ended September 30, 2015. The tax expense for the three months ended September 30, 2015 consists of a U.S. tax expense related to tax deductible goodwill that generates a deferred tax liability that cannot be used as a source of income against which deferred tax assets may be realized, and tax expense generated from foreign operations for the quarter. The benefit for income taxes for the nine months ended September 30, 2015 also includes a $2,268 benefit from income taxes due to the release of a portion of the U.S. valuation allowance in connection with the World Energy acquisition. The Company recorded a tax expense of $12,111 and $11,950 for the three month and nine month periods ended September 30, 2014, respectively. The tax expense for the three months ended September 30, 2014 consists of a tax expense on its foreign income, a U.S. tax expense related to state income taxes where no net operating losses are available, and a U.S. tax expense related to tax deductible goodwill that generates a deferred tax liability that cannot be used as a source of income against which deferred tax assets may be realized. The tax expense for the nine months ended September 30, 2014 includes a $1,069 benefit from income taxes due to the release of a portion of the U.S. valuation allowance in connection with the Entech acquisition during the three months ended June 30, 2014 and a $1,120 expense for deferred income taxes in connection with the sale of Utility Solution Consulting (Note 14) during the three months ended June 30, 2014. ASC 740, Income Taxes , provides criteria for the recognition, measurement, presentation and disclosures of uncertain tax positions. A tax benefit from an uncertain tax position may be recognized if it is “more likely than not” that the position is sustainable based solely on its technical merits. During the three and nine month periods ended September 30, 2015, there were no material changes in the Company’s uncertain tax positions. The Company makes judgments regarding the realizability of our deferred tax assets. The balance sheet carrying value of our net deferred tax assets is based on whether it believes that it is more likely than not that it will generate sufficient future taxable income to realize these deferred tax assets after consideration of all available evidence. The Company regularly reviews its deferred tax assets for recoverability considering historical profitability, projected future taxable income, the expected timing of the reversals of existing temporary differences and tax planning strategies. In assessing the need for a valuation allowance, it considers both positive and negative evidence related to the likelihood of realization of the deferred tax assets. The weight given to the positive and negative evidence is commensurate with the extent to which the evidence may be objectively verified. As such, it is generally difficult for positive evidence regarding projected future taxable income exclusive of reversing taxable temporary differences to outweigh objective negative evidence of recent financial reporting losses. Generally, cumulative loss in recent years is a significant piece of negative evidence that is difficult to overcome in determining that a valuation allowance is not needed. As of September 30, 2015, the Company has a valuation allowance recorded against certain deferred tax assets. If it is subsequently able to utilize all or a portion of the deferred tax assets for which the remaining valuation allowance has been established, then it may be required to recognize these deferred tax assets through the reduction of the valuation allowance which could result in a material benefit to our results of operations in the period in which the benefit is determined.

Concentrations of Credit Risk

Concentrations of Credit Risk	9 Months Ended
	Sep. 30, 2015
Risks and Uncertainties [Abstract]
Concentrations of Credit Risk	Concentrations of Credit Risk The Company's significant customers consist of PJM Interconnection (PJM) and Independent Market Operator (IMO). PJM is an electric power grid operator customer in the mid-Atlantic and New England regions of the United States that is comprised of multiple utilities and was formed to control the operation of the regional power system, coordinate the supply of electricity, and establish a fair and efficient market. IMO is an entity that was established to administer and operate the Western Australia (WA) wholesale electricity market. No other customers comprised more than 10% of consolidated revenues during the three or nine months ended September 30, 2015 and 2014 . The following table presents the Company’s significant customers. Three Months Ended September 30, 2015 2014 Revenues % of Total Revenues Revenues % of Total Revenues PJM $ 143,804 66 % $ 224,540 68 % IMO 6,726 3 % 42,983 13 % Nine Months Ended September 30, 2015 2014 Revenues % of Total Revenues Revenues % of Total Revenues PJM $ 161,618 47 % $ 245,752 58 % IMO 21,201 6 % $ 47,380 11 % PJM, Pacific Gas & Electric and Southern California Edison Company were the only customers that each comprised 10% or more of the Company’s accounts receivable balance at September 30, 2015, representing 10% , 11% and 13% , respectively. PJM, Southern California Edison Company and IMO were the only customers that each comprised 10% or more of the Company’s accounts receivable balance at December 31, 2014 , representing 21% , 17% and 12% , respectively. Unbilled revenue related to PJM was $110,584 and $96,404 at September 30, 2015 and December 31, 2014 , respectively. There was no significant unbilled revenue for any other customers at September 30, 2015 and December 31, 2014 . Deposits consist of funds to secure performance under certain contracts and open market bidding programs with electric power grid operator and utility customers. Deposits held by these customers were $47 and $3,033 at September 30, 2015 and December 31, 2014 , respectively.

Industry Segment Information

Industry Segment Information	9 Months Ended
	Sep. 30, 2015
Segment Reporting [Abstract]
Industry Segment Information	Industry Segment Information The Company views its operations and manages its business as one operating segment. Operating segments are defined as components of an enterprise about which separate financial information is available that is evaluated regularly by the chief operating decision maker, or decision making group, in making decisions on how to allocate resources and assess performance. The Company has determined that its chief operating decision maker is its Chief Executive Officer. The Company operates in the major geographic areas noted in the chart below. The “All other” designation includes revenues from other international locations, primarily consisting of Germany, Ireland, New Zealand, South Korea and the United Kingdom. Revenues are based upon the location of the Company's entity that provides the service, and internationally totaled $22,703 and $57,739 for the three months ended September 30, 2015 and 2014 , respectively and $64,254 and $80,471 for the nine months ended September 30, 2015 and 2014 . Revenues by geography as a percentage of total revenues are as follows: Three Months Ended September 30, Nine Months Ended September 30, 2015 2014 2015 2014 United States 90 % 82 % 81 % 81 % Australia 3 13 7 12 Canada 2 3 5 3 All other 5 2 7 4 Total 100 % 100 % 100 % 100 % As of September 30, 2015 and December 31, 2014, the long-lived tangible assets related to the Company’s international subsidiaries were less than 10% of the Company’s long-lived tangible assets and were deemed not material.

Legal Proceedings

Legal Proceedings	9 Months Ended
	Sep. 30, 2015
Commitments and Contingencies Disclosure [Abstract]
Legal Proceedings	Legal Proceedings The Company is subject to legal proceedings, claims and litigation arising in the ordinary course of business. The Company does not expect the ultimate costs to resolve these matters to have a material adverse effect on the Company’s consolidated financial condition, results of operations or cash flows. On November 6, 2014, a class action lawsuit was filed in the Delaware Court of Chancery against the Company, World Energy, Wolf Merger Sub Corporation, and members of the board of directors of World Energy arising out of the merger between the Company and World Energy. The lawsuit generally alleged that the members of the board of directors of World Energy breached their fiduciary duties to World Energy’s stockholders by entering into the merger agreement because they, among other things, failed to maximize stockholder value and agreed to preclusive deal-protection terms. The lawsuit also alleged that the Company and World Energy aided and abetted the board of directors of World Energy in breaching their fiduciary duties. The plaintiff sought to stop or delay the acquisition of World Energy by the Company, or rescission of the merger in the event it is consummated, and seeks monetary damages in an unspecified amount to be determined at trial. The parties engaged in settlement negotiations and on December 24, 2014, without admitting, but expressly denying any liability on behalf of the defendants, the parties entered into a memorandum of understanding (MOU) regarding a proposed settlement to resolve all allegations. The MOU was filed in the Delaware Court of Chancery. Among other things, the MOU provided that, in consideration for a release and the dismissal of the litigation, World Energy would include additional disclosures in a Form SC 14D9-A to be filed with the SEC no later than December 24, 2014. The MOU also provided that the litigation, including the preliminary injunction hearing, be stayed. The merger closed on January 5, 2015. On March 26, 2015, the parties executed and filed with the Delaware Chancery Court a formal stipulation of settlement. On August 20, 2015, after holding a hearing, the Delaware Court of Chancery Court approved the settlement.

Gain on Sale of Service Line (N

Gain on Sale of Service Line (Notes)	9 Months Ended
	Sep. 30, 2015
Discontinued Operations and Disposal Groups [Abstract]
Gain On Sale Of Service Line	Gain on Sale of Service Line On April 16, 2014, the Company entered into an agreement with a third party to sell a component of the business, Utility Solutions Consulting, that the Company acquired in connection with its acquisition of Global Energy Partners, Inc. (Global Energy) related to consulting and engineering support services to the global electric utility industry, with a particular focus on providing consulting services to utilities. On May 30, 2014, the Company sold the component for $4,750 . The Company concluded that Utility Solutions Consulting met the definition of a business in accordance with ASC 805. The following table summarizes the assets sold in connection with this transaction: Customer relationship intangible assets, net $ 153 Other definite-lived intangible assets, net 39 Goodwill 489 Total assets sold $ 681 The amount of goodwill allocated to Global Energy was based on the relative fair values of this business. In accordance with the agreement, the Company received $4,275 at closing and $475 was held in escrow to cover general representations and warranties, as well as, potential purchase price adjustment, if any, for fees that could have been earned related to contracts that were not assigned. The potential remaining purchase price adjustment for fees that could have been earned for contracts that were not assigned was $364 as of June 30, 2014. During the three months ended June 30, 2015, the Company was reimbursed $364 from escrow. The Company recognized a gain from the sale of Global Energy totaling $3,378 , net of transaction costs totaling $327 during the three months ended June 30, 2014. During the three months ended September 30, 2014, the remaining applicable contracts were assigned and the Company recognized $359 of the previously deferred gain resulting in a total gain recognized during the nine months ended September 30, 2014 of $3,737 . The Company concluded that the Utility Solutions Consulting disposal group meets the criteria of discontinued operations under ASC 205-20, Discontinued Operations (ASC 205-20). However, the Company determined that the operations of Utility Solutions Consulting were neither quantitatively or qualitatively material to the Company’s current or historical consolidated operations and therefore, the results of operations of Utility Solutions Consulting have not been presented as discontinued operations in the Company’s accompanying consolidated statements of operations for the three and nine months ended September 30, 2014 . As a result, the gain has been reflected as a separate component within income from operations with the corresponding discrete tax charge of $1,102 related to the increase in the deferred tax liability as a result of the increased book and tax basis difference in goodwill being recorded as a component of the Company’s provision for income taxes during the nine month periods ended September 30, 2014 .

Gain on Sale of Assets Gain on

Gain on Sale of Assets Gain on Sale of Assets	9 Months Ended
	Sep. 30, 2015
Gain on Sale of Assets [Abstract]
Gain On Sale Of Assets	Gain on Sale of Assets On April 22, 2014, the Company entered into an agreement with a third party, enterprise customer of the Company to sell its remaining two contractual demand response capacity resources related to an open market demand response program, which allowed the buyer to enroll directly with the applicable grid operator. Under the terms of the agreement, the Company agreed to sell each of these two demand response capacity resources with such sale and transfer being effective as of the date that each resource has been paid for in full. The aggregate payment of $5,740 was allocated between each demand response capacity resource based on each resource’s relative fair value as determined by the potential future cash flows from each resource with $2,171 being allocated to the first demand response capacity resource and $3,569 being allocated to the second demand response capacity resource, of which guaranteed fees of $517 were recognized ratably through the end of the contractual period of March 31, 2015. The third party fully paid the purchase price for the first demand response capacity resource during the three months ended June 30, 2014 and as a result, the sale of this resource was completed. As a result of the first sale, the Company recognized a gain on the sale of this asset equal to the purchase price of $2,171 during the nine months ended September 30, 2014 . During the nine months ended September 30, 2015, the Company received the remaining balance in the amount of $2,991 from the third party for the second demand response capacity resource and completed the sale resulting in the recognition of a gain on the sale of this asset equal to the purchase price of $2,991 .

Recent Accounting Pronouncement

Recent Accounting Pronouncements	9 Months Ended
	Sep. 30, 2015
Accounting Changes and Error Corrections [Abstract]
Recent Accounting Pronouncements	Recent Accounting Pronouncements In May 2014, the FASB issued guidance codified in ASC 606, Revenue Recognition - Revenue from Contracts with Customers (ASC 606), which amends the guidance in former ASC 605, Revenue Recognition , and most other existing revenue guidance in GAAP, to require an entity to recognize revenue in an amount that reflects the consideration to which the entity expects to be entitled in exchange for transferring goods or services to customers and provide additional disclosures. As amended, the effective date for public entities is annual reporting periods beginning after December 15, 2017 and interim periods therein. As such, we will be required to adopt the standard in the first quarter of fiscal year 2018. Early adoption is not permitted before the first quarter of fiscal year 2017. ASC 606 may be adopted either using a “full retrospective” approach, in which the standard is applied to all of the periods presented, or a “modified retrospective” approach. The Company is currently evaluating which transition method to use and how ASC 606 will affect its financial statements. In August 2014, the FASB issued Accounting Standards Update (ASU) 2014-15, Presentation of Financial Statements — Going Concern: Disclosure of Uncertainties about an Entity’s Ability to Continue as a Going Concern (ASU 2014-15). The standard requires that the Company evaluates, at each interim and annual reporting period, whether there are conditions or events that raise substantial doubt about its ability to continue as a going concern within one year after the date the financial statements are issued, and provide related disclosures. ASU 2014-15 is effective for annual periods ending after December 15, 2016, and for annual and interim periods thereafter, and early adoption is permitted. The Company does not expect to early adopt ASU 2014-15, which will be effective for its fiscal year ending December 31, 2016. The Company does not believe the standard will have a material impact on its consolidated financial position and results of operations. In April 2015, the FASB issued ASU 2015-03, Interest – Imputation of Interest (Subtopic 835-30): Simplifying the Presentation of Debt Issuance Costs (ASU 2015-03). The amendments in this update require that debt issuance costs related to a recognized debt liability (other than revolving credit facilities) be presented in the consolidated balance sheet as a direct deduction from the carrying amount of that debt liability, consistent with debt discounts. This update deals solely with financial statement display matters; recognition and measurement of debt issuance costs are unaffected. ASU 2015-03 is effective for annual periods ending after December 15, 2015, and interim periods within those fiscal years. Early adoption is permitted for financial statements that have not previously been issued. The Company does not expect to early adopt ASU 2015-03, which will be effective for its fiscal year ending December 31, 2016. The Company is currently in the process of evaluating the impact of adoption of this ASU on its consolidated financial position and results of operations. In April 2015, the FASB issued ASU 2015-05, Intangibles—Goodwill and Other—Internal-Use Software: Customer’s Accounting for Fees Paid in a Cloud Computing Arrangement (ASU 2015-05). The standard clarifies the circumstances under which a cloud computing customer would account for the arrangement as a license of internal-use software under ASC 350-40. ASU 2015-05 is effective for annual periods, including interim periods within those annual periods, beginning after December 15, 2015, and early adoption is permitted. The Company does not expect to early adopt ASU 2015-05, which will be effective for its fiscal year ending December 31, 2016. The Company does not believe the standard will have a material impact on its consolidated financial position and results of operations. In September 2015, the FASB issued 2015-16, Business Combinations (Topic 805): Simplifying the Accounting for Measurement-Period Adjustments (ASU 2015-16). The standard requires that an acquirer recognize adjustments to provisional amounts that are identified during the measurement period in the reporting period in which the adjustment amounts are determined. The standard update is effective for fiscal years beginning after December 15, 2015 and interim periods within those fiscal years. The standard update is to be applied prospectively to adjustments of provisional amounts that occur after the effective date with earlier application permitted for financial statements that have not been issued. The Company does not believe the standard will have a material impact on its consolidated financial position and results of operations.

Description of Business and B23

Description of Business and Basis of Presentation (Policies)	9 Months Ended
	Sep. 30, 2015
Accounting Policies [Abstract]
Description Of Business	Description of Business EnerNOC, Inc. (the Company) is a leading provider of energy intelligence software (EIS) and related solutions. The Company’s enterprise customers use the Company's Software-as-a-Service (SaaS) solutions to transform how they manage and control energy spend for their organizations, while utilities leverage the Company's SaaS solutions to better engage their customers, deliver savings and consumption reductions to help achieve energy efficiency mandates, manage system peaks and grid constraints, and increase demand for utility-provided products and services. The Company’s EIS and related solutions for utility customers and electric power grid operators also include the demand response solutions and applications, EnerNOC Demand Manager™ and EnerNOC Demand Resource™. EnerNOC Demand Manager is a SaaS application that provides utilities with the underlying technology to manage their demand response programs and secure reliable demand-side resources. EnerNOC Demand Resource is a turnkey demand response resource that matches obligation, in the form of megawatts (MWs) that the Company agrees to deliver to the Company’s utility customers and electric power grid operators, with supply, in the form of MWs that are curtailed from the electric power grid through its arrangements with its enterprise cust omers.
Basis of Consolidation	The condensed consolidated financial statements of the Company include the accounts of its wholly-owned subsidiaries. All significant transactions and balances between the Company and its subsidiaries have been eliminated. The Company owns 60% of EnerNOC Japan K.K, for which it consolidates the operations in accordance with Accounting Standards Codification (ASC) 810, Consolidation (ASC 810). The remaining 40% represents non-controlling interest in the accompanying unaudited condensed consolidated balance sheets and statements of operations.
Use of Estimates in Preparation of Financial Statements	Use of Estimates in Preparation of Financial Statements The preparation of financial statements in conformity with accounting principles generally accepted in the United States (GAAP) requires management to make estimates and assumptions that affect the amounts reported in the condensed consolidated financial statements and accompanying notes. Significant estimates made by management relate to revenue recognition reserves, allowances for doubtful accounts, valuations and purchase price allocations related to business combinations, including the fair value of intangible assets and accrued acquisition consideration, expected future cash flows used to evaluate the recoverability of long-lived assets, amortization methods and periods, certain accrued expenses and other related charges, stock-based compensation, contingent liabilities, tax reserves and recoverability of the Company’s net deferred tax assets and related valuation allowance. While the Company believes that such estimates are fair when considered in conjunction with the condensed consolidated financial position and results of operations taken as a whole, the actual amounts of such items, when known, will vary from these estimates.
Revenue Recognition	Revenue Recognition The Company recognizes revenues in accordance with ASC 605, Revenue Recognition (ASC 605). The Company's customers include enterprises, utilities and grid operators. The Company derives recurring revenues from the sale of EIS and related solutions. The Company recognizes revenue when it is earned and all of the following criteria are met: persuasive evidence of an arrangement exists, delivery has occurred, the fee is fixed or determinable, and we deem collection to be reasonably assured. The Company maintains a reserve for customer adjustments and allowances as a reduction in revenues. In determining the revenue reserve estimate, the Company relies on historical data and known performance adjustments. These factors, and unanticipated changes in the economic and industry environment, could cause the Company's reserve estimates to differ from actual results. The Company records a provision for estimated customer adjustments and allowances in the same period as the related revenues are recorded. These estimates are based on the specific facts and circumstances of a particular program, analysis of credit memo data, historical customer adjustments, and other known factors. If the data used to calculate these estimates does not properly reflect reserve requirements, then a change in the allowances would be made in the period in which such a determination was made and revenues in that period could be affected. The Company's enterprise revenues from the sales of EIS and related solutions to enterprise customers generally represent ongoing software or service arrangements under which the revenues are recognized ratably over the same period commencing upon delivery of the EIS and related solutions to the enterprise customer. Under certain of its arrangements, a portion of the fees received may be subject to adjustment or refund based on the validation of the energy savings delivered after the implementation is complete. As a result, the Company defers the portion of the fees that are subject to adjustment or refund until such time as the right of adjustment or refund lapses, which is generally upon completion and validation of the implementation.
Stock-Based Compensation	Stock-Based Compensation The Company maintains stock-based compensation plans for its employees and outside directors and accounts for stock-based compensation arrangements in accordance with the authoritative guidance, which requires the Company to measure and record compensation expense in its condensed consolidated financial statements using a fair value method. See Note 9 for further information regarding the Company’s stock-based compensation plans. I
Software Development Costs	Internal Use Software The Company applies the provisions of ASC 350-40, Internal-Use Software (ASC 350-40), which requires computer software costs associated with internal use software to be expensed as incurred until certain capitalization criteria are met. Internal use software development costs of $2,583 and $1,507 for the three months ended September 30, 2015 and 2014 , respectively, and $6,155 and $4,648 for the nine months ended September 30, 2015 and 2014 , have been capitalized in accordance with ASC 350-40. Capitalized costs are amortized over the assets' estimated useful lives. Amortization of capitalized software development costs was $1,893 and $1,547 for the three months ended September 30, 2015 and 2014 , respectively and $5,288 and $4,573 for the nine months ended September 30, 2015 and 2014 , respectively. Accumulated amortization of capitalized software development costs was $32,891 and $27,603 as of September 30, 2015 and December 31, 2014 , respectively.
Cost Method Investments	Cost Method Investments The Company holds investments in privately-held companies of approximately $2,500 and $1,000 as of September 30, 2015 and December 31, 2014, respectively, which are accounted for based on the cost method and are included in deposits and other assets in the accompanying condensed consolidated balance sheets. In August 2014, the Company purchased a convertible promissory note for a purchase price of $1,500 in a privately-held SaaS company that serves businesses seeking an innovative approach to measure and track the positive business impact of engaging employees in sustainability through technology. At the time of the purchase, the Company concluded that this investment should be accounted for as an available-for-sale investment and was classified as such as of December 31, 2014. During the nine months ended September 30, 2015, the note was converted into Series A-1 preferred stock. As the preferred stock does not have a readily determinable fair value it is exempt from the scope of ASC 320, Investments-Debt and Equity Securities, and is thus carried at cost as of September 30, 2015. The Company periodically reviews these investments for impairment. If the Company determines that an other-than-temporary impairment has occurred, it will write-down the investment to its fair value. For the three and nine months ended September 30, 2015, t
Subsequent Events Considerations	Subsequent Events Consideration The Company considers events or transactions that occur after the balance sheet date but prior to the issuance of the financial statements to provide additional evidence relative to certain estimates or to identify matters that require additional disclosure. Subsequent events have been evaluated as required.
Recent Accounting Pronouncements	16. Recent Accounting Pronouncements In May 2014, the FASB issued guidance codified in ASC 606, Revenue Recognition - Revenue from Contracts with Customers (ASC 606), which amends the guidance in former ASC 605, Revenue Recognition , and most other existing revenue guidance in GAAP, to require an entity to recognize revenue in an amount that reflects the consideration to which the entity expects to be entitled in exchange for transferring goods or services to customers and provide additional disclosures. As amended, the effective date for public entities is annual reporting periods beginning after December 15, 2017 and interim periods therein. As such, we will be required to adopt the standard in the first quarter of fiscal year 2018. Early adoption is not permitted before the first quarter of fiscal year 2017. ASC 606 may be adopted either using a “full retrospective” approach, in which the standard is applied to all of the periods presented, or a “modified retrospective” approach. The Company is currently evaluating which transition method to use and how ASC 606 will affect its financial statements. In August 2014, the FASB issued Accounting Standards Update (ASU) 2014-15, Presentation of Financial Statements — Going Concern: Disclosure of Uncertainties about an Entity’s Ability to Continue as a Going Concern (ASU 2014-15). The standard requires that the Company evaluates, at each interim and annual reporting period, whether there are conditions or events that raise substantial doubt about its ability to continue as a going concern within one year after the date the financial statements are issued, and provide related disclosures. ASU 2014-15 is effective for annual periods ending after December 15, 2016, and for annual and interim periods thereafter, and early adoption is permitted. The Company does not expect to early adopt ASU 2014-15, which will be effective for its fiscal year ending December 31, 2016. The Company does not believe the standard will have a material impact on its consolidated financial position and results of operations. In April 2015, the FASB issued ASU 2015-03, Interest – Imputation of Interest (Subtopic 835-30): Simplifying the Presentation of Debt Issuance Costs (ASU 2015-03). The amendments in this update require that debt issuance costs related to a recognized debt liability (other than revolving credit facilities) be presented in the consolidated balance sheet as a direct deduction from the carrying amount of that debt liability, consistent with debt discounts. This update deals solely with financial statement display matters; recognition and measurement of debt issuance costs are unaffected. ASU 2015-03 is effective for annual periods ending after December 15, 2015, and interim periods within those fiscal years. Early adoption is permitted for financial statements that have not previously been issued. The Company does not expect to early adopt ASU 2015-03, which will be effective for its fiscal year ending December 31, 2016. The Company is currently in the process of evaluating the impact of adoption of this ASU on its consolidated financial position and results of operations. In April 2015, the FASB issued ASU 2015-05, Intangibles—Goodwill and Other—Internal-Use Software: Customer’s Accounting for Fees Paid in a Cloud Computing Arrangement (ASU 2015-05). The standard clarifies the circumstances under which a cloud computing customer would account for the arrangement as a license of internal-use software under ASC 350-40. ASU 2015-05 is effective for annual periods, including interim periods within those annual periods, beginning after December 15, 2015, and early adoption is permitted. The Company does not expect to early adopt ASU 2015-05, which will be effective for its fiscal year ending December 31, 2016. The Company does not believe the standard will have a material impact on its consolidated financial position and results of operations. In September 2015, the FASB issued 2015-16, Business Combinations (Topic 805): Simplifying the Accounting for Measurement-Period Adjustments (ASU 2015-16). The standard requires that an acquirer recognize adjustments to provisional amounts that are identified during the measurement period in the reporting period in which the adjustment amounts are determined. The standard update is effective for fiscal years beginning after December 15, 2015 and interim periods within those fiscal years. The standard update is to be applied prospectively to adjustments of provisional amounts that occur after the effective date with earlier application permitted for financial statements that have not been issued. The Company does not believe the standard will have a material impact on its consolidated financial position and results of operations.

Acquisition (Tables)

Acquisition (Tables)	9 Months Ended
	Sep. 30, 2015
Business Combinations [Abstract]
Schedule of Purchase Consideration Paid	The following table summarizes the purchase consideration paid for World Energy: Purchase consideration: Cash paid for stock, stock awards and warrants $ 70,445 Repayment of debt 9,468 Fair value of consideration transferred $ 79,913
Components and Preliminary Allocation of Purchase Price	As of the filing date of this Quarterly Report on Form 10-Q, the Company remains in the process of valuing the assets acquired and liabilities assumed of World Energy’s business, including accounts receivable and other liabilities. Cash $ 2,702 Accounts receivable (1) 8,946 Prepaid expenses and other current assets 1,596 Property and equipment 449 Identified intangible assets 41,400 Goodwill 39,560 Accounts payable, accrued expenses and other liabilities (1) (12,247 ) Deferred revenue (320 ) Deferred tax liabilities, net (2,173 ) Total $ 79,913
Schedule of Asset and Liabilities Held-for-sale	The following table summarizes the assets and liabilities held for sale as of September 30, 2015 : As of September 30, 2015 Goodwill $ 751 Inventories 623 Fixed assets 49 Assets held for sale $ 1,423 Accounts payable $ (422 ) Deferred revenue (55 ) Liabilities held for sale $ (477 )

Intangible Assets (Tables)

Intangible Assets (Tables)	9 Months Ended
	Sep. 30, 2015
Goodwill and Intangible Assets Disclosure [Abstract]
Summary of Gross Carrying Amount and Accumulated Amortization of Definite-Lived Intangible Assets	The following table provides the gross carrying amount and related accumulated amortization of the Company's definite-lived intangible assets as of September 30, 2015 and December 31, 2014 : As of September 30, 2015 As of December 31, 2014 Weighted Average Amortization Period (in years) Gross Carrying Amount Accumulated Amortization Gross Carrying Amount Accumulated Amortization Customer relationships 6.86 $ 60,715 $ (23,527 ) $ 37,516 $ (19,725 ) Customer contracts 1.33 7,896 (6,398 ) 4,912 (3,618 ) Employment and non-compete agreements 0.94 3,091 (2,174 ) 3,198 (1,821 ) Software 0.00 170 (170 ) 120 (120 ) Developed technology 6.36 24,561 (6,063 ) 13,615 (3,407 ) Trade name 0.25 1,097 (1,002 ) 1,124 (777 ) Patents 4.38 180 (97 ) 180 (86 ) Total $ 97,710 $ (39,431 ) $ 60,665 $ (29,554 )

Goodwill (Tables)

Goodwill (Tables)	9 Months Ended
	Sep. 30, 2015
Goodwill and Intangible Assets Disclosure [Abstract]
Schedule of Changes in Carrying Amount of Goodwill	The following table shows the change of the carrying amount of goodwill from December 31, 2014 to September 30, 2015 : Balance at December 31, 2014 $ 114,939 Foreign currency translation impact (4,769 ) Acquisition of World Energy (Note 2) 39,560 Assets held for sale (751 ) Current period purchase price adjustment (1) 260 Balance at September 30, 2015 $ 149,239

Net Income (Loss) Per Share (Ta

Net Income (Loss) Per Share (Tables)	9 Months Ended
	Sep. 30, 2015
Earnings Per Share [Abstract]
Computation of Basic and Diluted Net Income (Loss) per Share	Computation of basic and diluted net income (loss) per share is as follows (in thousands, except per share information): Three Months Ended Nine Months Ended Numerator: 2015 2014 2015 2014 Net income (loss) for basic earnings per share 12,987 96,673 (56,095 ) 38,875 ADD: Interest expense related to convertible notes 2,118 980 6,251 980 Net income (loss) for diluted earnings per share 15,105 97,653 (49,844 ) 39,855
Reconciliation of Basic and Diluted Share Amounts	Denominator: Basic weighted average common shares outstanding 28,507,939 27,795,154 28,282,647 28,075,291 Weighted average common stock equivalents 340,707 877,088 — 1,068,138 Incremental shares from assumed conversion of convertible notes 5,774,928 2,761,922 — 930,758 Diluted weighted average common shares outstanding 34,623,574 31,434,164 28,282,647 30,074,187 Basic net income (loss) per share $ 0.46 $ 3.48 $ (1.98 ) $ 1.38 Diluted net income (loss) per share $ 0.44 $ 3.11 $ (1.98 ) $ 1.33 Anti-dilutive shares relate to: Stock options 473,848 1,667 418,024 4,602 Nonvested restricted stock 2,285,100 91,755 2,228,630 384,031 Restricted stock units 72,261 7,144 72,261 10,076 Convertible debt — — 5,774,928 —

Fair Value Measurements (Tables

Fair Value Measurements (Tables)	9 Months Ended
	Sep. 30, 2015
Fair Value Disclosures [Abstract]
Assets and Liabilities Measured at Fair Value on Recurring Basis	The table below presents the balances of assets and liabilities measured at fair value on a recurring basis at September 30, 2015 and December 31, 2014 : Totals Quoted Prices in Significant Other (Level 2) Unobservable Inputs (Level 3) Fair Value Measurement at September 30, 2015 Assets: Money market funds (1) $ 113,745 $ 113,745 $ — $ — Liabilities: Contingent purchase price consideration (2) 803 — — 803 Fair Value Measurement at December 31, 2014 Assets: Money market funds (1) $ 225,815 $ 225,815 $ — $ — Liabilities: Contingent purchase price consideration (2) 649 — — 649 (1) The money market funds balance included in cash and cash equivalents represents the only asset that the Company measures and records at fair value on a recurring basis. These money market funds represent excess operating cash that is invested daily into an overnight investment account. (2) Accrued contingent purchase price consideration relates to the Company’s acquisitions of Activation Energy DSU Limited (Activation Energy) and Entelios AG (Entelios) in February 2014. As of September 30, 2015 , approximately $700 associated with the Activation Energy acquisition has been reflected in accrued expense and other current liabilities in the condensed consolidated balance sheet. The additional $103 relates to the Entelios earn-out, which is reflected in other liabilities in the condensed consolidated balance sheet. As of December 31, 2014, approximately $312 was recorded in accrued expense and other current liabilities, while the remaining $337 was recorded in other liabilities in the condensed consolidated balance sheet.
Liabilities Measured on Recurring Basis with Unobservable Input Reconciliation	The following is a rollforward of the Level 3 assets and liabilities from January 1, 2015 through September 30, 2015 : Liabilities Balance January 1, 2015 $ 649 Cash payment during the period (277 ) Increase due to change in assumptions and present value accretion 468 Change due to movement in foreign exchange rates (37 ) Balance September 30, 2015 $ 803

Borrowings and Credit Arrange29

Borrowings and Credit Arrangements (Tables)	9 Months Ended
	Sep. 30, 2015
Debt Disclosure [Abstract]
Summary of Interest Expense	Interest expense under the Notes is as follows: Three Months Ended Nine Months Ended 2015 2014 2015 2014 Accretion of debt discount $ 1,043 $ 474 $ 3,063 $ 474 Amortization of deferred financing costs 175 76 508 76 Non-cash interest expense 1,218 550 3,571 550 2.25% accrued interest 900 430 2,680 430 Total interest expense from Notes $ 2,118 $ 980 $ 6,251 $ 980

Stockholders' Equity Stockholde

Stockholders' Equity Stockholders' Equity (Tables)	9 Months Ended
	Sep. 30, 2015
Share-based Compensation Arrangement by Share-based Payment Award
Schedule of Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Table Text Block]	Stock-based compensation expense recorded in the unaudited condensed consolidated statements of operations was as follows: Three Months Ended September 30, Nine Months Ended September 30, 2015 2014 2015 2014 Selling and marketing expenses $ 1,243 $ 1,512 $ 3,194 $ 4,077 General and administrative expenses 2,061 2,262 7,187 7,066 Research and development expenses 351 361 1,004 1,018 Total stock-based compensation expense (1) $ 3,655 $ 4,135 $ 11,385 $ 12,161
Summary of Company's Stock Option Activity	The following is a summary of the Company’s stock option activity during the nine months ended September 30, 2015 : Nine Months Ended September 30, 2015 Number of Shares Underlying Options Exercise Price Per Share Weighted- Average Exercise Price Per Share Aggregate Intrinsic Value Outstanding at December 31, 2014 725,578 $0.35 - $43.38 $ 18.01 $ 2,978 (2) Granted 78,413 10.99 Exercised (109,617 ) 9.80 771 (3) Canceled (57,624 ) 16.60 Outstanding at September 30, 2015 636,750 $0.51 - $43.38 $ 18.69 $ 933 (4) Weighted average remaining contractual life in years: 2.2 Exercisable at end of period 603,208 $0.51 - $43.38 $ 19.06 $ 932 (4) Weighted average remaining contractual life in years: 2.1 Vested or expected to vest at September 30, 2015 (1) 634,234 $0.51 - $43.38 $ 18.69 $ 933 (4) (1) This represents the number of vested options as of September 30, 2015 plus the number of non-vested options expected to vest as of September 30, 2015 based on a 7.5% forfeiture rate. (2) The aggregate intrinsic value was calculated based on the positive difference between the estimated fair value of the Company’s common stock on December 31, 2014 of $15.45 and the weighted-average exercise price of the underlying options. (3) The aggregate intrinsic value was calculated based on the difference between the fair value of the Company’s common stock on the applicable exercise dates and the weighted-average exercise price of the underlying options. (4) The aggregate intrinsic value was calculated based on the positive difference between the estimated fair value of the Company’s common stock on September 30, 2015 of $7.90 and the weighted-average exercise price of the underlying options.
Restricted Stock
Share-based Compensation Arrangement by Share-based Payment Award
Summary of Company's Restricted Stock and Restricted Stock Units Activity	The following table summarizes the Company’s restricted stock activity during the nine months ended September 30, 2015 : Number of Shares Weighted Average Grant Date Fair Value Per Share Nonvested at December 31, 2014 2,170,267 $ 17.18 Granted 1,439,283 10.98 Vested (834,269 ) 16.13 Cancelled (317,526 ) 15.67 Nonvested at September 30, 2015 2,457,755 $ 14.60
Restricted Stock Units
Share-based Compensation Arrangement by Share-based Payment Award
Summary of Company's Restricted Stock and Restricted Stock Units Activity	The following table summarizes the Company’s restricted stock unit activity during the nine months ended September 30, 2015 : Number of Shares Weighted Average Grant Date Fair Value Per Share Nonvested at December 31, 2014 256,872 $ 20.08 Granted 69,950 10.59 Vested (4,939 ) 19.64 Cancelled (39,266 ) 19.00 Nonvested at September 30, 2015 282,617 $ 17.84

Concentrations of Credit Risk (

Concentrations of Credit Risk (Tables)	9 Months Ended
	Sep. 30, 2015
Risks and Uncertainties [Abstract]
Concentrations of Credit Risk of Significant Customers	The following table presents the Company’s significant customers. Three Months Ended September 30, 2015 2014 Revenues % of Total Revenues Revenues % of Total Revenues PJM $ 143,804 66 % $ 224,540 68 % IMO 6,726 3 % 42,983 13 % Nine Months Ended September 30, 2015 2014 Revenues % of Total Revenues Revenues % of Total Revenues PJM $ 161,618 47 % $ 245,752 58 % IMO 21,201 6 % $ 47,380 11 %

Industry Segment Information (T

Industry Segment Information (Tables)	9 Months Ended
	Sep. 30, 2015
Segment Reporting [Abstract]
Schedule of Revenue from External Customers and Long-Lived Assets, by Geographical Areas	Revenues by geography as a percentage of total revenues are as follows: Three Months Ended September 30, Nine Months Ended September 30, 2015 2014 2015 2014 United States 90 % 82 % 81 % 81 % Australia 3 13 7 12 Canada 2 3 5 3 All other 5 2 7 4 Total 100 % 100 % 100 % 100 %

Gain on Sale of Service Line (T

Gain on Sale of Service Line (Tables)	9 Months Ended
	Sep. 30, 2015
Discontinued Operations and Disposal Groups [Abstract]
Summary Of Assets Sold	The following table summarizes the assets sold in connection with this transaction: Customer relationship intangible assets, net $ 153 Other definite-lived intangible assets, net 39 Goodwill 489 Total assets sold $ 681

Description of Business and B34

Description of Business and Basis of Presentation - Additional Information (Detail)	3 Months Ended		9 Months Ended		12 Months Ended
	Sep. 30, 2015USD ($)	Sep. 30, 2014USD ($)	Sep. 30, 2015USD ($)	Sep. 30, 2014USD ($)	Dec. 31, 2014USD ($)	Aug. 31, 2014USD ($)	Dec. 10, 2013
Description Of Business And Basis Of Presentation
Ownership percentage by parent							60.00%
Ownership percentage by noncontrolling interest							40.00%
Decrease to accrued vacation expense	$ (2,308,000)
Revenue reserves					$ 475,000
Penalties incurred as a result of under performance, multiplier of shortfall			0.0192
Cost Method Investments	2,500,000		$ 2,500,000		1,000,000
Impact of error adjustment on cost of revenues	143,146,000	$ 168,564,000	208,645,000	$ 232,505,000
PJM
Description Of Business And Basis Of Presentation
Unbilled revenues	110,584,000		110,584,000		96,404,000
Demand Response Equipment
Description Of Business And Basis Of Presentation
Demand response revenues	198,701,000	318,629,000	282,845,000	396,051,000
Software Development Costs
Description Of Business And Basis Of Presentation
Capitalized software development costs	2,583,000	1,507,000	6,155,000	4,648,000
Amortization of capitalized software development costs	1,893,000	$ 1,547,000	5,288,000	$ 4,573,000
Accumulated amortization of capitalized software development costs	$ 32,891,000		$ 32,891,000		27,603,000
Recognition of Payments Owed to Enterprise Customers [Member]
Description Of Business And Basis Of Presentation
Impact of error adjustment on cost of revenues					$ 610,000
Convertible Promissory Note
Description Of Business And Basis Of Presentation
Cost Method Investments, Original Cost						$ 1,500,000

Acquisition - Additional Inform

Acquisition - Additional Information (Detail) - USD ($) $ / shares in Units, $ in Thousands	Jun. 30, 2015	Jan. 05, 2015	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Business Acquisition
Purchase price net of acquired cash		$ 77,211			$ 77,559	$ 36,406
Stock-based compensation expense			$ 3,655	$ 4,135	11,385	12,161
Amortization of acquired intangible assets			3,662	2,391	11,607	6,753
Customer Relationships
Business Acquisition
Acquired finite-lived intangible assets, weighted average useful life	4 years 2 months 12 days
Customer Contracts
Business Acquisition
Acquired finite-lived intangible assets, weighted average useful life	14 years 2 months 12 days
Developed Technology
Business Acquisition
Acquired finite-lived intangible assets, weighted average useful life	9 years 2 months 12 days
Amortization of acquired intangible assets			923	515	2,848	1,482
General and Administrative Expenses
Business Acquisition
Stock-based compensation expense			2,061	$ 2,262	7,187	$ 7,066
World Energy Solutions
Business Acquisition
Purchase price per share		$ 5.50
Aggregate purchase price		$ 79,913
Acquired cash		2,702
Consideration transferred to repay debt		9,468
Business combination cost to settle outstanding stock awards		3,027
Cash paid for stock awards		1,849
Post-combination stock-based compensation		1,178
Stock-based compensation expense		$ 443	$ 2		495
Post-combination stock-based compensation, period of recognition		2 years 3 months 18 days
Cash paid for warrants		$ 58
Identified intangible assets		41,400
Acquisition accounting adjustment to Accounts Receivable					391
Acquisition accounting adjustment to Accrued Expenses					$ 300
World Energy Solutions | Customer Relationships
Business Acquisition
Identified intangible assets		29,160
World Energy Solutions | Developed Technology
Business Acquisition
Identified intangible assets		12,240
World Energy Solutions | General and Administrative Expenses
Business Acquisition
Transaction costs expensed		$ 367

Acquisition - Components and Pr

Acquisition - Components and Preliminary Allocation of Purchase Price (Detail) - USD ($) $ in Thousands	Jan. 05, 2015	Sep. 30, 2015	Sep. 30, 2014	Dec. 31, 2014
Business Acquisition
Payments to Acquire Businesses, Net of Cash Acquired	$ 77,211	$ 77,559	$ 36,406
Goodwill		$ 149,239		$ 114,939
World Energy Solutions
Business Acquisition
Cash paid for stock, stock awards and warrants	70,445
Repayment of debt	9,468
Fair value of consideration transferred	79,913
Cash	2,702
Payments to Acquire Businesses, Gross, Shares Outstanding	68,538
Accounts receivable (1)	8,946
Prepaid expenses and other current assets	1,596
Property and equipment	449
Identified intangible assets	41,400
Goodwill	39,560
Accounts payable, accrued expenses and other liabilities (1)	(12,247)
Deferred revenue	(320)
Deferred tax liabilities, net	(2,173)
Total	$ 79,913

Acquisition - Schedule of Net T

Acquisition - Schedule of Net Tangible Assets and Liabilities Acquired (Detail) - USD ($) $ in Thousands	Sep. 30, 2015	Dec. 31, 2014
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations
Liabilities held for sale	$ (477)	$ 0
World Energy Efficiency Services Business
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations
Accounts receivable	751
Inventories	623
Fixed assets	49
Assets held for sale	1,423
Accounts payable	(422)
Deferred revenue	(55)
Liabilities held for sale	$ (477)

Intangible Assets (Detail)

Intangible Assets (Detail) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Finite-Lived Intangible Assets
Amortization expenses of intangible assets	$ 3,662	$ 2,391	$ 11,607	$ 6,753
Estimated amortization, 2015	2,945		2,945
Estimated amortization, 2016	10,943		10,943
Estimated amortization, 2017	9,175		9,175
Estimated amortization, 2018	7,172		7,172
Estimated amortization, 2019	5,893		5,893
Estimated amortization, thereafter	22,151		$ 22,151
Minimum
Finite-Lived Intangible Assets
Intangible asset estimated useful lives			1 year
Maximum
Finite-Lived Intangible Assets
Intangible asset estimated useful lives			15 years
Weighted Average
Finite-Lived Intangible Assets
Intangible asset estimated useful lives			6 years
Developed Technology
Finite-Lived Intangible Assets
Amortization expenses of intangible assets	$ 923	$ 515	$ 2,848	$ 1,482
Intangible asset estimated useful lives			6 years 4 months 10 days

Intangible Assets - Summary of

Intangible Assets - Summary of Gross Carrying Amount and Accumulated Amortization of Definite-Lived Intangible Assets (Detail) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2015	Dec. 31, 2014
Finite-Lived Intangible Assets
Gross carrying amount	$ 97,710	$ 60,665
Accumulated amortization	$ (39,431)	(29,554)
Customer Relationships
Finite-Lived Intangible Assets
Weighted average amortization period (in years)	6 years 10 months 10 days
Gross carrying amount	$ 60,715	37,516
Accumulated amortization	$ (23,527)	(19,725)
Customer Contracts
Finite-Lived Intangible Assets
Weighted average amortization period (in years)	1 year 3 months 29 days
Gross carrying amount	$ 7,896	4,912
Accumulated amortization	$ (6,398)	(3,618)
Employment Agreements and Non-Compete Agreements
Finite-Lived Intangible Assets
Weighted average amortization period (in years)	11 months 9 days
Gross carrying amount	$ 3,091	3,198
Accumulated amortization	$ (2,174)	(1,821)
Software
Finite-Lived Intangible Assets
Weighted average amortization period (in years)	0 years
Gross carrying amount	$ 170	120
Accumulated amortization	$ (170)	(120)
Developed Technology
Finite-Lived Intangible Assets
Weighted average amortization period (in years)	6 years 4 months 10 days
Gross carrying amount	$ 24,561	13,615
Accumulated amortization	$ (6,063)	(3,407)
Trade Name
Finite-Lived Intangible Assets
Weighted average amortization period (in years)	3 months
Gross carrying amount	$ 1,097	1,124
Accumulated amortization	$ (1,002)	(777)
Patents
Finite-Lived Intangible Assets
Weighted average amortization period (in years)	4 years 4 months 17 days
Gross carrying amount	$ 180	180
Accumulated amortization	$ (97)	$ (86)

Goodwill Schedule of Changes in

Goodwill Schedule of Changes in Carrying Amount of Goodwill (Details) $ in Thousands	9 Months Ended
	Sep. 30, 2015USD ($)
Goodwill [Roll Forward]
Balance at December 31, 2014	$ 114,939
Foreign currency translation impact	(4,769)
Acquisition of World Energy	114,939
Assets held for sale	(751)
Balance at September 30, 2015	149,239
Goodwill, Purchase Accounting Adjustments	$ 260

Net Income (Loss) Per Share Net

Net Income (Loss) Per Share Net income (Loss) per Share - Computation of Basic and Diluted Net Income (Loss) (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Earnings Per Share, Basic, by Common Class, Including Two Class Method [Line Items]
Net income (loss) for basic earnings per share	$ 12,987	$ 96,673	$ (56,095)	$ 38,875
Net income (loss) for diluted earnings per share	15,105	97,653	(49,844)	39,855
2.25% Convertible Senior Notes Due 2019
Earnings Per Share, Basic, by Common Class, Including Two Class Method [Line Items]
ADD: Interest expense related to convertible notes	1,218	550	3,571	550
Interest Expense, Debt	$ 2,118	$ 980	$ 6,251	$ 980

Net Income (Loss) Per Share (De

Net Income (Loss) Per Share (Detail) - USD ($)	9 Months Ended
	Sep. 30, 2015	Aug. 12, 2014
Antidilutive Securities Excluded from Computation of Earnings Per Share
Debt Instrument, Interest Rate, Stated Percentage	2.25%
Number of common stock shares held in escrow	87,483
M2M Communications Corporation
Antidilutive Securities Excluded from Computation of Earnings Per Share
Shares to be issued related to deferred consideration arrangement related to a business combination	254,654
2.25% Convertible Senior Notes Due 2019
Antidilutive Securities Excluded from Computation of Earnings Per Share
Debt Instrument, Face Amount		$ 160,000,000
Debt Instrument, Interest Rate, Stated Percentage		2.25%

Net Income (Loss) Per Share - R

Net Income (Loss) Per Share - Reconciliation of Basic and Diluted Share Amounts (Detail) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Antidilutive Securities Excluded from Computation of Earnings Per Share
Basic weighted average common shares outstanding	28,507,939	27,795,154	28,282,647	28,075,291
Weighted average common stock equivalents	340,707	877,088	0	1,068,138
Diluted weighted average common shares outstanding	34,623,574	31,434,164	28,282,647	30,074,187
Basic (in dollars per share)	$ 0.46	$ 3.48	$ (1.98)	$ 1.38
Diluted (in dollars per share)	$ 0.44	$ 3.11	$ (1.98)	$ 1.33
Net income (loss) for basic earnings per share	$ 12,987	$ 96,673	$ (56,095)	$ 38,875
Net income (loss) for diluted earnings per share	$ 15,105	$ 97,653	$ (49,844)	$ 39,855
Stock Options
Anti-dilutive shares relate to:
Weighted average anti-dilutive shares	473,848	1,667	418,024	4,602
Nonvested Restricted Stock
Anti-dilutive shares relate to:
Weighted average anti-dilutive shares	2,285,100	91,755	2,228,630	384,031
Restricted Stock Units
Anti-dilutive shares relate to:
Weighted average anti-dilutive shares	72,261	7,144	72,261	10,076
Convertible Debt Securities
Antidilutive Securities Excluded from Computation of Earnings Per Share
Incremental shares from assumed conversion of convertible notes	5,774,928	2,761,922	0	930,758
Anti-dilutive shares relate to:
Weighted average anti-dilutive shares	0	0	5,774,928	0

Fair Value Measurements (Detail

Fair Value Measurements (Details) - USD ($)	Sep. 30, 2015	Dec. 31, 2014	Aug. 12, 2014
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Cost Method Investments	$ 2,500,000	$ 1,000,000
Fair value of convertible debt	$ 112,800,000	$ 133,392,000
2.25% Convertible Senior Notes Due 2019
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Debt Instrument, Face Amount			$ 160,000,000

Fair Value Measurements - Asset

Fair Value Measurements - Assets and Liabilities Measured at Fair Value on Recurring Basis (Detail) - USD ($) $ in Thousands		Sep. 30, 2015		Dec. 31, 2014
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Convertible Debt, Fair Value Disclosures		$ 112,800		$ 133,392
Fair Value Measurement, Recurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Money market funds	[1]	113,745		225,815
Accrued contingent purchase price consideration		803	[2]	649
Fair Value Measurement, Recurring | Quoted Prices in Active Markets for Identical Assets (Level 1)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Money market funds	[1]	113,745		225,815
Accrued contingent purchase price consideration		0	[2]	0
Fair Value Measurement, Recurring | Significant Other Observable Inputs (Level 2)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Money market funds	[1]	0		0
Accrued contingent purchase price consideration		0	[2]	0
Fair Value Measurement, Recurring | Unobservable Inputs (Level 3)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Money market funds	[1]	0		0
Accrued contingent purchase price consideration		803	[2]	649
Entelios AG
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Accrued acquisition consideration related to liability		103
Accrued Expense And Other Current Liabilities | Activation Energy
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Accrued acquisition consideration related to liability		$ 700		312
Accrued Acquisition Consideration
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Accrued acquisition consideration related to liability				$ 337
[1]	The money market funds balance included in cash and cash equivalents represents the only asset that the Company measures and records at fair value on a recurring basis. These money market funds represent excess operating cash that is invested daily into an overnight investment account.
[2]	Accrued contingent purchase price consideration relates to the Company’s acquisitions of Activation Energy DSU Limited (Activation Energy) and Entelios AG (Entelios) in February 2014. As of September 30, 2015, approximately $700 associated with the Activation Energy acquisition has been reflected in accrued expense and other current liabilities in the condensed consolidated balance sheet. The additional $103 relates to the Entelios earn-out, which is reflected in other liabilities in the condensed consolidated balance sheet. As of December 31, 2014, approximately $312 was recorded in accrued expense and other current liabilities, while the remaining $337 was recorded in other liabilities in the condensed consolidated balance sheet.

Fair Value Measurements - Ass46

Fair Value Measurements - Assets and Liabilities Measured on Recurring Basis with Unobservable Inputs Reconciliation (Detail) $ in Thousands	9 Months Ended
	Sep. 30, 2015USD ($)
Liabilities
Balance January 1, 2015	$ 649
Cash payment during the period	(277)
Increase due to change in assumptions and present value accretion	468
Change due to movement in foreign exchange rates	(37)
Balance September 30, 2015	$ 803

Borrowings and Credit Arrange47

Borrowings and Credit Arrangements (Detail)	Aug. 12, 2014USD ($)	Sep. 30, 2015USD ($)	Sep. 30, 2015USD ($)	Aug. 18, 2014USD ($)	Aug. 11, 2014USD ($)
Line of Credit Facility
Debt Instrument, Interest Rate, Stated Percentage		2.25%	2.25%
Prepaid expense and other current assets		$ 710,000	$ 710,000
2.25% Convertible Senior Notes Due 2019
Line of Credit Facility
Debt Instrument, Face Amount	$ 160,000,000
Debt Instrument, Interest Rate, Stated Percentage	2.25%
Conversion ratio (in shares per $1,000 principal amount)	0.0360933
Debt instrument liability component				$ 137,430,000
Debt instrument equity component		22,570,000	$ 22,570,000
Amortization period for interest expense			5 years
Deposit and other current assets		2,285,000	$ 2,285,000
Senior Notes Liability Component
Line of Credit Facility
Transaction cost allocated			4,056,000
Senior Notes Equity Component
Line of Credit Facility
Transaction cost allocated			666,000
Debt Instrument Transaction Costs Reimbursed		400,000
Silicon Valley Bank | 2014 Credit Facility
Line of Credit Facility
Remaining borrowing capacity		7,401,000	7,401,000
Silicon Valley Bank | 2014 Credit Facility | Revolving Credit Facility
Line of Credit Facility
Maximum borrowing capacity					$ 30,000,000
Outstanding borrowings					$ 0
Silicon Valley Bank | 2014 Credit Facility | Letter of Credit
Line of Credit Facility
Outstanding letters of credit		$ 22,599,000	$ 22,599,000

Borrowings and Credit Arrange48

Borrowings and Credit Arrangements - Summary of Interest Expense (Detail) - 2.25% Convertible Senior Notes Due 2019 - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Debt Instrument
Accretion of debt discount	$ 1,043	$ 474	$ 3,063	$ 474
Amortization of deferred financing costs	175	76	508	76
Non-cash interest expense	1,218	550	3,571	550
2.25% accrued interest	900	430	2,680	430
Total interest expense from Notes	$ 2,118	$ 980	$ 6,251	$ 980

Commitments and Contingencies (

Commitments and Contingencies (Detail) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2015	Dec. 31, 2014
Other Commitments
Restricted cash	$ 2,314	$ 813
Performance guarantees	20,410
Deposits held by customers	47	$ 3,033
Deferred fees	600
Estimated termination penalty	7,422
Customer refundable fees	20,100
Customer deferred fees	2,772
Silicon Valley Bank | 2014 Credit Facility | Letter of Credit
Other Commitments
Outstanding letters of credit	$ 22,599

Stockholders' Equity Stockhol50

Stockholders' Equity Stockholders' Equity (Details) - $ / shares	3 Months Ended	9 Months Ended
	Sep. 30, 2015	Sep. 30, 2015	May. 27, 2015	Dec. 31, 2014
Class of Stock
Share Based Compensation Arrangement By Share Based Payment Award Options Outstanding Number Held By Non Employees	283	283
Weighted average period of stocks		1 year 7 months 6 days
Outstanding options	636,750	636,750		725,578
Weighted average exercise price of options outstanding (in dollars per share)	$ 18.69	$ 18.69		$ 18.01
Vesting period		4 years
2014 Long-Term Incentive Plan
Class of Stock
Stock repurchased	68,367	311,244
Shares available for future grant	2,580,300	2,580,300
World Energy Solutions, Inc. 2006 Stock Incentive Plan
Class of Stock
Shares available for future grant	94,517	94,517
Number of shares authorized			1,700,000

Stcokholders' Equity - Share Re

Stcokholders' Equity - Share Repurchase Program (Details) - USD ($)	Aug. 12, 2014	Sep. 30, 2015	Sep. 30, 2015	Aug. 08, 2015	Aug. 11, 2014
Equity, Class of Treasury Stock
Share price	$ 19.79
2014 Share Repurchase Program
Equity, Class of Treasury Stock
Number of shares authorized under stock repurchase program				$ 50,000,000	$ 50,000,000
Proceeds from notes offering used to repurchase shares	$ 29,975,000
Stock repurchased	1,514,552
2014 Long-Term Incentive Plan
Equity, Class of Treasury Stock
Stock repurchased		68,367	311,244

Stockholders' Equity - Stock Ba

Stockholders' Equity - Stock Based Compensation Additional Information (Details) - USD ($) $ / shares in Units, $ in Thousands	Jan. 05, 2015	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014	Dec. 31, 2014
Share-based Compensation Arrangement by Share-based Payment Award
Options, exercisable period				10 years
Vesting period				4 years
Common stock outstanding held by employees				72,926	6,632
Weighted average grant date fair value				$ 9.92
Stock options outstanding held by employees		636,467		636,467
Weighted average period of stocks				1 year 7 months 6 days
Stock-based compensation expense		$ 3,655	$ 4,135	$ 11,385	$ 12,161
Tax Benefit from Compensation Expense		219			219
Employees And Directors
Share-based Compensation Arrangement by Share-based Payment Award
Nonvested stock-based compensation expense related to employees		461		461
Non-vested Awards
Share-based Compensation Arrangement by Share-based Payment Award
Stock-based compensation expense		834
Performance Shares
Share-based Compensation Arrangement by Share-based Payment Award
Stock-based compensation expense		$ 128	129	$ 380	382
Restricted Stock
Share-based Compensation Arrangement by Share-based Payment Award
Total number of shares of restricted stock granted during the period				1,439,283
Nonvested shares		2,457,755		2,457,755		2,170,267
Nonvested restricted shares forfeited				317,526
Restricted Stock Units
Share-based Compensation Arrangement by Share-based Payment Award
Total number of shares of restricted stock granted during the period				69,950
Nonvested shares		282,617		282,617		256,872
Nonvested restricted shares forfeited				39,266
Restricted Stock Service Based
Share-based Compensation Arrangement by Share-based Payment Award
Nonvested stock-based compensation expense related to employees						$ 631
Weighted average period of stocks						3 years 1 month 6 days
Restricted Stock Performance Based Vesting Awards Probable Vesting
Share-based Compensation Arrangement by Share-based Payment Award
Nonvested stock-based compensation expense related to employees		$ 2,075		$ 2,075
Weighted average period of stocks				1 year 4 months 24 days
Restricted Stock Performance Based Vesting Awards Not Probable Vesting
Share-based Compensation Arrangement by Share-based Payment Award
Nonvested stock-based compensation expense related to employees		4,220		$ 4,220
Restricted Stock And Restricted Units
Share-based Compensation Arrangement by Share-based Payment Award
Nonvested stock-based compensation expense related to employees		23,427		$ 23,427
Weighted average period of stocks				2 years 8 months 12 days
World Energy Solutions
Share-based Compensation Arrangement by Share-based Payment Award
Stock-based compensation expense	$ 443	2		$ 495
Entelios AG | Restricted Stock Units | Non - Executive Employees
Share-based Compensation Arrangement by Share-based Payment Award
Non-vested restricted stock						250,382
General and Administrative Expenses
Share-based Compensation Arrangement by Share-based Payment Award
Stock-based compensation expense		2,061	2,262	7,187	7,066
Research and Development Expenses
Share-based Compensation Arrangement by Share-based Payment Award
Stock-based compensation expense		351	361	1,004	1,018
Selling and Marketing Expenses
Share-based Compensation Arrangement by Share-based Payment Award
Stock-based compensation expense		$ 1,243	$ 1,512	$ 3,194	$ 4,077

Stockholders' Equity - Summary

Stockholders' Equity - Summary of Company's Stock Option Activity (Details) - USD ($) $ / shares in Units, $ in Thousands		3 Months Ended		9 Months Ended			12 Months Ended
		Sep. 30, 2015		Sep. 30, 2015		Sep. 30, 2014	Dec. 31, 2014
Number of Shares Underlying Options (in shares):
Outstanding at beginning of period				725,578
Granted				78,413
Exercised				(109,617)
Canceled				(57,624)
Outstanding at end of period		636,750		636,750			725,578
Exercisable at end of period		603,208		603,208
Vested or expected to vest at end of period	[1]	634,234		634,234
Outstanding, exercise price per share, minimum (in dollars per share)				$ 0.51			$ 0.35
Outstanding, exercise price per share, maximum (in dollars per share)				43.38			43.38
Exercisable at end of period, exercise pricer per share, minimum (in dollars per share)				0.51
Exercisable at end of period, exercise pricer per share, maximum (in dollars per share)				43.38
Vested and expected to vest at end of period, exercise price per share, minimum (in dollars per share)	[1]			0.51
Vested and expected to vest at end of period, exercise price per share, maximum (in dollars per share)	[1]			$ 43.38
Outstanding, weighted average remaining contractual life in years				2 years 2 months 12 days
Exercisable, weighted average remaining contractual life in years				2 years 1 month 6 days
Weighted-Average Exercise Price Per Share (in dollars per share):
Outstanding at beginning of period				$ 18.01
Granted				10.99
Exercised				9.80
Canceled				16.60
Outstanding at end of period		$ 18.69		18.69			$ 18.01
Exercisable at end of period		19.06		19.06
Vested or expected to vest at end of period	[1]	$ 18.69		$ 18.69
Aggregate Intrinsic Value:
Outstanding at beginning of period	[2]			$ 2,978
Exercised	[3]			771
Outstanding at end of period		$ 933	[4]	933	[4]		$ 2,978	[2]
Exercisable at end of period	[4]	932		932
Vested and expected to vest at end of period	[1],[4]	$ 933		$ 933
Expected forfeiture rate				7.50%
Fair value of common stock		$ 7.90		$ 7.90			$ 15.45
Tax Benefit from Compensation Expense		$ 219				$ 219
[1]	This represents the number of vested options as of September 30, 2015 plus the number of non-vested options expected to vest as of September 30, 2015 based on a 7.5% forfeiture rate.
[2]	The aggregate intrinsic value was calculated based on the positive difference between the estimated fair value of the Company’s common stock on December 31, 2014 of $15.45 and the weighted-average exercise price of the underlying options.
[3]	The aggregate intrinsic value was calculated based on the difference between the fair value of the Company’s common stock on the applicable exercise dates and the weighted-average exercise price of the underlying options.
[4]	The aggregate intrinsic value was calculated based on the positive difference between the estimated fair value of the Company’s common stock on September 30, 2015 of $7.90 and the weighted-average exercise price of the underlying options.

Stockholders' Equity - Restrict

Stockholders' Equity - Restricted Stock (Details) - Restricted Stock - $ / shares	6 Months Ended	9 Months Ended
	Jan. 02, 2016	Sep. 30, 2015
Number of Shares:
Nonvested at beginning of period		2,170,267
Granted		1,439,283
Vested		(834,269)
Cancelled		(317,526)
Nonvested at end of period		2,457,755
Weighted Average Grant Date Fair Value Per Share (in dollars per share):
Nonvested at beginning of period		$ 17.18
Granted		10.98
Vested		16.13
Cancelled		15.67
Nonvested at end of period		$ 14.60
Expected to Vest
Number of Shares:
Vested	(12,514)

Stockholders' Equity - Restri55

Stockholders' Equity - Restricted Stock Units (Details) - Restricted Stock Units	9 Months Ended
	Sep. 30, 2015$ / sharesshares
Number of Shares:
Nonvested at beginning of period	256,872
Granted	69,950
Vested	(4,939)
Cancelled	(39,266)
Nonvested at end of period	282,617
Weighted Average Grant Date Fair Value Per Share (in dollars per share):
Nonvested at beginning of period | $ / shares	$ 20.08
Granted | $ / shares	10.59
Vested | $ / shares	19.64
Cancelled | $ / shares	19
Nonvested at end of period | $ / shares	$ 17.84

Income Taxes (Detail)

Income Taxes (Detail) - USD ($) $ in Thousands	3 Months Ended			9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Jun. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Income Tax Disclosure [Abstract]
Provision (benefit) from income taxes	$ 417	$ 12,111		$ (1,523)	$ 11,950
Benefit from income taxes due to release of portion valuation allowance				$ 2,268	$ 1,069
Deferred income taxes in connection with sale of Utility Solution Consulting			$ 1,120

Concentrations of Credit Risk57

Concentrations of Credit Risk (Detail) - USD ($) $ in Thousands	9 Months Ended	12 Months Ended
	Sep. 30, 2015	Dec. 31, 2014
Concentration Risk
Deposits held by customers	$ 47	$ 3,033
PJM
Concentration Risk
Unbilled revenue	$ 110,584	$ 96,404
Accounts Receivable | Customer Concentration Risk | PJM
Concentration Risk
Share in accounts receivable from major customers	10.00%	21.00%
Accounts Receivable | Customer Concentration Risk | Pacific Gas and Electric [Member]
Concentration Risk
Share in accounts receivable from major customers	11.00%
Accounts Receivable | Customer Concentration Risk | IMO
Concentration Risk
Share in accounts receivable from major customers		12.00%
Accounts Receivable | Customer Concentration Risk | Southern California Edison Company
Concentration Risk
Share in accounts receivable from major customers	13.00%	17.00%

Concentrations of Credit Risk -

Concentrations of Credit Risk - Concentrations of Credit Risk of Significant Customers (Detail) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Concentration Risk
Revenues	$ 217,324	$ 329,422	$ 340,375	$ 425,985
PJM
Concentration Risk
Revenues	143,804	224,540	161,618	245,752
IMO
Concentration Risk
Revenues	$ 6,726	$ 42,983	$ 21,201	$ 47,380
Revenues | Customer Concentration Risk | PJM
Concentration Risk
% of Total Revenues	66.00%	68.00%	47.00%	58.00%
Revenues | Customer Concentration Risk | IMO
Concentration Risk
% of Total Revenues	3.00%	13.00%	6.00%	11.00%

Industry Segment Information (D

Industry Segment Information (Details) - USD ($) $ in Thousands	3 Months Ended				6 Months Ended		9 Months Ended
	Sep. 30, 2015	Jun. 30, 2015	Sep. 30, 2014	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Segment Reporting Information
Revenues	$ 217,324		$ 329,422				$ 340,375	$ 425,985
Entity wide revenue by geographical region, percent		100.00%		100.00%	100.00%	100.00%
International Customers
Segment Reporting Information
Revenues	$ 22,703		$ 57,739				$ 64,254	$ 80,471
AUSTRALIA
Segment Reporting Information
Entity wide revenue by geographical region, percent		3.00%		13.00%	7.00%	12.00%
CANADA
Segment Reporting Information
Entity wide revenue by geographical region, percent		2.00%		3.00%	5.00%	3.00%
All Other [Member]
Segment Reporting Information
Entity wide revenue by geographical region, percent		5.00%		2.00%	7.00%	4.00%
UNITED STATES
Segment Reporting Information
Entity wide revenue by geographical region, percent		90.00%		82.00%	81.00%	81.00%

Gain on Sale of Service Line -

Gain on Sale of Service Line - Additional Information (Details) - USD ($) $ in Thousands	1 Months Ended	3 Months Ended		9 Months Ended		12 Months Ended
	Jun. 30, 2014	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014	Dec. 31, 2014	May. 30, 2014
Long Lived Assets Held-for-sale [Line Items]
Consideration received from sale of business							$ 4,275
Helf for escrow to cover general representation and warranties							475
Potential remaining purchase price	$ 364
Gain recognized from sale		$ 0	$ 359	$ 0	$ 3,737
Net of transaction costs and other expenses						$ 327
Increase in deferred tax liability						1,102
Utility Solutions Consulting Services [Member]
Long Lived Assets Held-for-sale [Line Items]
Sale of utility solutions consulting services							$ 4,750
Service Line Contracts [Member]
Long Lived Assets Held-for-sale [Line Items]
Gain recognized from sale			$ 359		$ 3,737	$ 3,378

Gain on Sale of Service Line 61

Gain on Sale of Service Line - Summary of Assets Sold (Details) $ in Thousands	May. 30, 2014USD ($)
Long Lived Assets Held-for-sale [Line Items]
Intangible assets sold	$ 681
Customer Relationships
Long Lived Assets Held-for-sale [Line Items]
Intangible assets sold	153
Other Intangible Assets [Member]
Long Lived Assets Held-for-sale [Line Items]
Intangible assets sold	39
Goodwill [Member]
Long Lived Assets Held-for-sale [Line Items]
Intangible assets sold	$ 489

Gain on Sale of Assets Gain o62

Gain on Sale of Assets Gain on Sale of Assets (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended		12 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014	Dec. 31, 2014	Apr. 22, 2014
Finite-Lived Intangible Assets
Aggregate payment of demand response capacity resource						$ 5,740
Contract default fees					$ 517
Gain on sale of assets	$ 0	$ 0	$ 2,991	$ 2,171
Proceeds from sale of assets			$ 2,991	$ 2,171
Asset One [Member]
Finite-Lived Intangible Assets
Aggregate payment of demand response capacity resource						2,171
Asset Two [Member]
Finite-Lived Intangible Assets
Aggregate payment of demand response capacity resource						$ 3,569