Enernoc (ENOC) 10-Q 4 Nov 16 2016 Q3 Quarterly report Financial data

Document and Entity Information

Document and Entity Information - shares	9 Months Ended
	Sep. 30, 2016	Nov. 01, 2016
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, 2016
Document Fiscal Year Focus	2,016
Document Fiscal Period Focus	Q3
Amendment Flag	false
Entity Common Stock, Shares Outstanding		30,906,610

Unaudited Condensed Consolidate

Unaudited Condensed Consolidated Balance Sheets - USD ($) $ in Thousands	Sep. 30, 2016	Dec. 31, 2015
Current assets:
Cash and cash equivalents	$ 81,499	$ 138,120
Restricted cash	732	464
Trade accounts receivable, net of allowance for doubtful accounts of $946 and $947 at September 30, 2016 and December 31, 2015, respectively	56,967	43,355
Unbilled revenue	72,123	70,101
Capitalized incremental direct customer contract costs	1,389	33,917
Prepaid expenses and other current assets	15,147	7,654
Total current assets	227,857	293,611
Property and equipment, net of accumulated depreciation of $127,762 and $114,828 at September 30, 2016 and December 31, 2015, respectively	43,098	49,653
Goodwill	38,258	39,747
Intangible assets, net	40,391	54,352
Deposits and other assets	3,852	6,351
Total assets	353,456	443,714
Current liabilities:
Accounts payable	973	6,002
Accrued capacity payments	80,582	104,278
Accrued payroll and related expenses	16,699	18,058
Accrued expenses and other current liabilities	13,419	20,734
Deferred revenue	9,436	55,631
Total current liabilities	121,109	204,703
Deferred revenue	3,305	3,696
Other liabilities	7,415	9,118
Convertible senior notes	114,205	111,254
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, 31,098,291 and 30,797,289 shares issued and outstanding at September 30, 2016 and December 31, 2015, respectively	31	30
Additional paid-in capital	385,071	377,473
Accumulated other comprehensive loss	(3,790)	(8,524)
Accumulated deficit	(274,146)	(254,335)
Total EnerNOC, Inc. stockholders’ equity	107,166	114,644
Noncontrolling interest	256	299
Total stockholders’ equity	107,422	114,943
Total liabilities and stockholders’ equity	$ 353,456	$ 443,714

Unaudited Condensed Consolidat3

Unaudited Condensed Consolidated Balance Sheets (Parenthetical) - USD ($) $ in Thousands	Sep. 30, 2016	Dec. 31, 2015
Statement of Financial Position [Abstract]
Trade accounts receivable, net of allowance for doubtful accounts	$ 946	$ 947
Property and equipment, net of accumulated depreciation	$ 127,762	$ 114,828
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	31,098,291	30,797,289
Shares outstanding	31,098,291	30,797,289

Unaudited Condensed Consolidat4

Unaudited Condensed Consolidated Statements of Income - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Revenues:
Revenues	$ 167,781	$ 217,324	$ 353,855	$ 340,375
Cost of revenues	96,965	143,146	211,090	208,645
Gross profit	70,816	74,178	142,765	131,730
Operating expenses:
Selling and marketing	20,008	22,397	70,540	74,563
General and administrative	20,331	26,707	75,688	83,450
Research and development	6,352	6,626	22,029	21,812
Gains on sale of businesses	2,229	0	19,605	2,991
Restructuring Charges	2,933	0	6,627	0
Total operating expenses	47,395	55,730	155,279	176,834
Income (loss) from operations	23,421	18,448	(12,514)	(45,104)
Other expense, net	(279)	(2,814)	(613)	(5,766)
Interest expense	(1,835)	(2,253)	(5,456)	(6,785)
Income (loss) before income tax	21,307	13,381	(18,583)	(57,655)
Benefit from (provision for) income tax	(689)	(417)	(1,271)	1,523
Net income (loss)	20,618	12,964	(19,854)	(56,132)
Net loss attributable to noncontrolling interest	(7)	(23)	(43)	(37)
Net income (loss) attributable to EnerNOC, Inc.	$ 20,625	$ 12,987	$ (19,811)	$ (56,095)
Net income (loss) attributable to EnerNOC, Inc. per common share
Basic (in dollars per share)	$ 0.70	$ 0.46	$ (0.68)	$ (1.98)
Diluted (in dollars per share)	$ 0.65	$ 0.44	$ (0.68)	$ (1.98)
Weighted average number of common shares used in computing net income (loss) per common share
Weighted Average Number of Shares Outstanding, Basic	29,349,772	28,507,939	29,188,693	28,282,647
Diluted (in shares)	34,326,256	34,623,574	29,188,693	28,282,647
Software
Revenues:
Revenues	$ 18,729	$ 18,028	$ 51,994	$ 55,353
Demand Response
Revenues:
Revenues	$ 149,052	$ 199,296	$ 301,861	$ 285,022

Unaudited Condensed Consolidat5

Unaudited Condensed Consolidated Statements of Comprehensive Loss - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Statement of Comprehensive Income [Abstract]
Net income (loss)	$ 20,618	$ 12,964	$ (19,854)	$ (56,132)
Foreign currency translation adjustments	575	(2,069)	2,331	(4,719)
Reclassification of cumulative translation adjustments due to liquidation of a foreign entity	(2,403)	0	(2,403)	0
Comprehensive income (loss)	23,596	10,895	(15,120)	(60,851)
Comprehensive loss attributable to noncontrolling interest	(7)	(24)	(43)	(43)
Comprehensive income (loss) attributable to EnerNOC, Inc.	$ 23,603	$ 10,919	$ (15,077)	$ (60,808)

Unaudited Condensed Consolidat6

Unaudited Condensed Consolidated Statements of Cash Flows - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015
Cash flows from operating activities
Net income (loss)	$ (19,854)	$ (56,132)
Adjustments to reconcile net loss to net cash used in operating activities:
Depreciation	17,095	17,652
Amortization of acquired intangible assets	8,694	11,607
Stock-based compensation	10,236	10,890
Gains on sale of businesses, excluding transaction costs	(20,405)	(2,991)
Impairment of property and equipment	2,593	495
Unrealized foreign exchange (gain) loss	(766)	6,010
Deferred income taxes	(80)	(2,271)
Non-cash interest expense	3,007	3,791
Other, net	818	547
Changes in operating assets and liabilities, net of effects of acquisitions and divestitures:
Trade accounts receivable	(14,873)	(13,199)
Unbilled revenue	(1,189)	(14,429)
Prepaid expenses and other current assets	(4,166)	(7,353)
Capitalized incremental direct customer contract costs	32,644	(12,766)
Other noncurrent assets	737	(844)
Deferred revenue	(42,000)	23,017
Accrued capacity payments	(24,466)	39,367
Accrued payroll and related expenses	(1,481)	(2,692)
Accounts payable, accrued expenses and other current liabilities	(10,476)	(19,462)
Other noncurrent liabilities	(956)	537
Net cash used in operating activities	(64,888)	(18,226)
Cash flows from investing activities
Purchases of property and equipment and capitalization of internal use software costs	(13,688)	(17,724)
Payments made for acquisitions, net of cash acquired	(840)	(77,559)
Proceeds from sale of businesses	23,157	2,991
Change in restricted cash and deposits	212	3,411
Net cash provided by (used in) investing activities	8,841	(88,881)
Cash flows from financing activities
Proceeds from convertible debt offering	0	400
Proceeds from exercises of stock options	10	1,074
Payments made for employee restricted stock minimum tax withholdings	(1,937)	(3,805)
Debt issuance costs	(75)	0
Net cash used in financing activities	(2,002)	(2,331)
Effects of exchange rate changes on cash and cash equivalents	1,428	(2,973)
Net change in cash and cash equivalents	(56,621)	(112,411)
Cash and cash equivalents at beginning of period	138,120	254,351
Cash and cash equivalents at end of period	81,499	141,940
Supplemental disclosure of cash flow information
Cash paid for interest	2,497	2,993
Cash paid for income taxes	1,977	4,046
Non-cash investing and financing activities
Issuance of common stock in connection with acquisitions	0	103
Issuance of common stock in satisfaction of bonuses	265	865
Acquisition of property and equipment in accrued expenses	483	$ 1,940
Common shares received for settlement of escrow account	$ 635

Description of Business and Bas

Description of Business and Basis of Presentation	9 Months Ended
	Sep. 30, 2016
Accounting Policies [Abstract]
Description of Business and Basis of Presentation	1. Description of Business and Basis of Presentation Description of Business EnerNOC, Inc. (the Company) is a leading provider of energy intelligence software (EIS) and demand response solutions to enterprises, utilities, and electric power grid operators. The Company’s EIS provides enterprises with a Software-as-a-Service (SaaS) energy management application that enables them to better manage and control energy costs for their organizations. The Company offers premium professional services that support the implementation of its EIS and help its enterprise customers set their energy management strategy. The Company's professional services offerings also include energy audits and retro-commissioning. The Company’s demand response solutions provide utilities and electric power grid operators with a managed service demand response resource that matches obligation in the form of megawatts (MWs) that the Company agrees to deliver to utilities and/or electric power grid operators, with supply, in the form of MWs that are curtailed from the electric power grid through the Company's arrangements with commercial and industrial end-users of energy (C&I end-users). The Company’s demand response solutions are also capable of providing utilities with the underlying technology to manage their own utility-sponsored demand response programs and secure reliable demand-side resources. Reclassifications Effective during the first quarter of 2016, the Company began operating as two reportable segments: Software and Demand Response. The Company updated the presentation of the revenue categories on its consolidated statements of operations for the three and nine months ended September 30, 2016 to present revenue for each of these segments. The Company has reclassified prior period revenue categories to conform to the current period presentation. This reclassification had no impact on total revenue or any other income statement result. For further discussion regarding the Company's reorganization and the impact on segment reporting, please refer to Note 2. Basis of Presentation The accompanying unaudited condensed consolidated financial statements of the Company include the accounts of its wholly-owned subsidiaries and have been prepared by the Company in accordance with accounting principles generally accepted in the United States (GAAP) for interim financial information pursuant to Rule 10-01 of Regulation S-X. Accordingly, they do not include all of the information and notes required by GAAP for complete financial statements. Intercompany transactions and balances are eliminated in consolidation. 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 unaudited condensed consolidated financial statements and accompanying notes. The Company owns 60% of EnerNOC Japan K.K., for which it consolidates the results of operations and financial position in the accompanying financial statements. The remaining 40% represents a noncontrolling interest in the accompanying unaudited condensed consolidated balance sheets and statements of operations. Use of Estimates The preparation of financial statements in conformity with 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, expected future cash flows used to evaluate the recoverability of long-lived assets, amortization methods and periods, valuation of cost-method investments, certain accrued expenses and other related charges, stock-based compensation, contingent liabilities, tax reserves and the 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, may vary from these estimates. Summary of Significant Accounting Policies The Company’s significant accounting policies are described in Note 1, “Description of Business, Basis of Presentation and Summary of Significant Accounting Policies,” in the Company’s Annual Report on Form 10-K for the fiscal year ended December 31, 2015 (2015 Form 10-K). Recently Adopted Accounting Standards In April 2015, the Financial Accounting Standards Board (FASB) issued Accounting Standards Update (ASU) 2015-05, Customer’s Accounting for Fees Paid in a Cloud Computing Arrangement (ASU 2015-05) . ASU 2015-05 amends Accounting Standards Codification (ASC) 350-40, Internal Use Software , to exclude cloud-computing arrangements from its scope. The guidance was effective as of January 1, 2016 for arrangements entered into or materially modified after the effective date. The Company adopted this standard prospectively on January 1, 2016 and the adoption of ASU 2015-05 did not have a material impact on the Company's consolidated financial statements.

Segment Information

Segment Information	9 Months Ended
	Sep. 30, 2016
Segment Reporting [Abstract]
Segment Information	2. Segment Information Effective in the first quarter of 2016 , the Company began operating as two reportable segments: Software and Demand Response. The Company’s Chief Operating Decision Maker (CODM), who is the Company's Chief Executive Officer, primarily evaluates the business and assesses performance based on the revenue and adjusted EBITDA of the Company's Software and Demand Response segments. The Company defines segment adjusted EBITDA as segment income (loss) from operations excluding depreciation, amortization and asset impairments; stock-based compensation and restructuring charges. In addition, the Company does not allocate to its operating segments certain corporate level expenses; gains on the sale of businesses; and direct and incremental expenses and gains associated with acquisitions, divestitures, reorganizations and settlements. Management considers segment adjusted EBITDA to be an important indicator of the segments' operational strength and the performance of its businesses. The financial results of each segment are based on revenues from external customers, cost of revenues and operating expenses that are directly attributable to the segment and an allocation of costs from shared functions. These shared functions include, but are not limited to, facilities, human resources, information technology, and engineering. Allocations are made based on management’s judgment of the most relevant cost drivers, such as head count, number of customer sites, or other operational data that contributes to the shared costs. Certain corporate level expenses, including executive, legal, and finance, have not been allocated as they are not attributable to either segment. Segment level asset information has not been provided as such information is not reviewed by the CODM for purposes of assessing segment performance and allocating resources. There are no intersegment sales or transactions. The accounting policies of the reportable segments are consistent with those described in Note 1, “Description of Business, Basis of Presentation and Summary of Significant Accounting Policies,” in the Company's 2015 Form 10-K. Software Segment The Software segment provides enterprises with the Company's EIS, which includes subscription software, energy procurement solutions, and professional services. The Software segment is responsible for developing and maintaining the Company's software platform; selling and marketing to enterprise customers; supporting customer relationships and managing customer projects; delivering software implementations, trainings, and other professional services; and managing contracts, invoicing and collection activities related to Software customer contracts. Demand Response Segment The Demand Response segment provides utilities and electric power grid operators with the Company’s demand response solutions. The Demand Response segment is responsible for developing and shaping demand response markets and securing future demand response obligations; procuring MWs that are available for curtailment through arrangements with C&I end-users; installing and maintaining a network of EnerNOC site servers to collect energy data for use in the management of demand response programs and to support the Company's subscription software offerings; providing C&I end-users and certain utility customers with software tools to manage their demand response activities; coordinating the curtailment of MWs for delivery to utilities and electric power grid operators when called upon; and financially settling with utilities, electric power grid operators, and C&I end-users. The following table presents segment revenue and segment adjusted EBITDA, along with the reconciliation of segment adjusted EBITDA to consolidated income (loss) before income tax: Three Months Ended September 30, Nine Months Ended September 30, Revenues: 2016 2015 2016 2015 Software Subscription software $ 7,221 $ 4,916 $ 18,966 $ 14,234 Procurement solutions 9,840 8,398 27,568 25,874 Professional services 1,668 4,714 5,460 15,245 Total Software Revenue 18,729 18,028 51,994 55,353 Demand Response Grid operator 121,500 171,928 252,985 237,281 Utility 27,552 27,368 48,876 47,741 Total Demand Response Revenue 149,052 199,296 301,861 285,022 Consolidated Revenue $ 167,781 $ 217,324 $ 353,855 $ 340,375 Three Months Ended September 30, Nine Months Ended September 30, 2016 2015 2016 2015 Segment Adjusted EBITDA: Software adjusted EBITDA $ (10,583 ) $ (13,842 ) $ (48,620 ) $ (49,088 ) Demand Response adjusted EBITDA 46,299 49,433 70,780 56,630 Total Segment adjusted EBITDA 35,716 35,591 22,160 7,542 Reconciliation to consolidated income (loss) before income tax Corporate unallocated expenses (4,239 ) (3,884 ) (14,446 ) (12,043 ) Depreciation, amortization and asset impairments (1) (7,418 ) (9,511 ) (25,888 ) (29,259 ) Stock-based compensation (3,452 ) (3,655 ) (10,236 ) (11,385 ) Restructuring charges (Note 3) (2,933 ) — (6,627 ) — Gains on sale of businesses (Note 4) 2,229 — 19,605 2,991 Direct and incremental (expenses) gains associated with acquisitions, divestitures, reorganizations and settlements (2) 3,525 (70 ) 2,961 (2,913 ) Noncontrolling interest expense (7 ) (23 ) (43 ) (37 ) Interest and other income (expense), net (2,114 ) (5,067 ) (6,069 ) (12,551 ) Consolidated income (loss) before income tax $ 21,307 $ 13,381 $ (18,583 ) $ (57,655 ) (1) Includes impairments of equipment excluded from restructuring charges. (2) Includes expenses that are direct and incremental to business acquisitions and divestitures, including third party professional fees for legal, accounting and valuation services; employee related costs associated with reorganizing the business; and a gain recorded in the three and nine months ended September 30, 2016 associated with the recovery of an escrow settlement claim as further described in Note 9.

Restructuring Activities

Restructuring Activities	9 Months Ended
	Sep. 30, 2016
Restructuring and Related Activities [Abstract]
Restructuring Activities	3. Restructuring Activities On May 23, 2016, the Board of Directors of the Company approved a restructuring plan (the Q2 2016 Restructuring Plan) to reduce its North American workforce by approximately 5% in order to enhance the Company’s strategic focus, deliver operational and cost efficiencies, and hold its utility customer engagement (UCE) business for sale. On September 21, 2016, the Board of Directors of the Company approved a restructuring plan (the Q3 2016 Restructuring Plan) to reduce the Company's global workforce by approximately 15% in order to materially reduce operating expenses, primarily related to the Company’s subscription-based energy intelligence software business. Workforce Reduction The Q2 2016 Restructuring Plan resulted in employee related charges of $271 and $1,146 for the three and nine months ended September 30, 2016. Specifically, the charges represent severance for terminated employees and retention costs for employees who remained with the Company until the UCE business was sold. These expenses were all paid by September 30, 2016 and no further costs are expected related to the Q2 2016 Restructuring Plan. In addition, as a result of the sale of an additional component of the business (see Note 4), the Company incurred $325 in incremental retention bonuses that are included in restructuring charges for the nine months ended September 30, 2016. The Q3 2016 Restructuring Plan resulted in employee related charges of $1,983 for the three and nine months ended September 30, 2016. The Company expects to complete the Q3 2016 Restructuring Plan by December 31, 2016, incurring a total aggregate expense of approximately $2,200 . Unpaid severance benefits associated with these charges was $1,616 as of September 30, 2016. Contract Terminations During the three months ended September 30, 2016 , the Company terminated certain vendor contracts primarily associated with annual trade shows and conferences. As a result, the Company recognized a $679 charge for termination fees and non-refundable deposits. Asset Impairments During the three months ended June 30, 2016, the Company modified a non-cancelable sublease agreement with a third party for excess office space in its corporate headquarters. In connection with this sublease, the Company determined that the carrying value for the associated leasehold improvements and furniture and fixtures would not be recovered, resulting in a $2,494 impairment charge. As the Company evaluates future cost savings, additional facility charges may be incurred. The following table summarizes the current year restructuring activities. These charges are included in "restructuring charges" on the consolidated statements of operations. As discussed in Note 2, these charges are excluded from the Company's segment adjusted EBITDA. Employee Related Contract Terminations Asset Impairments Total Accrued restructuring liability at January 1, 2016 $ — $ — $ — $ — Charges for the three and six months ended June 30, 2016 1,200 — 2,494 3,694 Cash payments (1,082 ) — — (1,082 ) Adjustments for non-cash items — — (2,494 ) (2,494 ) Accrued restructuring liability at June 30, 2016 118 — — 118 Charges for the three months ended September 30, 2016 2,254 679 — 2,933 Cash payments (756 ) (679 ) — (1,435 ) Accrued restructuring liability at September 30, 2016 $ 1,616 $ — $ — $ 1,616 Total restructuring charges for the nine months ended September 30, 2016 $ 3,454 $ 679 $ 2,494 $ 6,627

Gain on Sale of Businesses

Gain on Sale of Businesses	9 Months Ended
	Sep. 30, 2016
Discontinued Operations and Disposal Groups [Abstract]
Business Held for Sale	4. Gains on Sale of Businesses On August 31, 2016, the Company entered into a definitive stock purchase agreement with a 9% shareholder to sell the UCE business, which was a component of the Software segment. On August 31, 2016 the Company completed the sale of the UCE business for $11,500 . In accordance with the agreement, $1,500 of the purchase price has been placed in escrow to cover general representations and warranties and is included in "prepaid expenses and other current assets" on the consolidated balance sheet. Other than amounts held in escrow, there were no significant amounts due to or from the buyer as of September 30, 2016. In connection with the sale of the UCE business, all of the Company's equity interest in a wholly-owned foreign subsidiary was transferred to the buyer and, following the sale, the Company had no retained investment or interest in the subsidiary. Accordingly, the net assets of the subsidiary were deconsolidated and the associated cumulative currency translation adjustments, which were in an unrealized loss position prior to the sale, were reclassified from accumulated other comprehensive loss and included as a reduction to the gain on the sale of the business. On May 31, 2016, the Company sold the utility programs group (UPG) business, which provided professional services to utilities with an emphasis on energy efficiency initiatives and was a component of the Software segment. The UPG business was sold to a third party for $14,471 in cash, of which $1,600 was placed in escrow to cover general representations and warranties and is included in "prepaid expenses and other current assets" on the consolidated balance sheet. The purchase price reflects a working capital adjustment of $286 that was accrued as of September 30, 2016 and settled in October 2016. The Company concluded that the sales of the UCE and UPG businesses did not qualify as discontinued operations as the disposals did not represent a strategic shift that will have a major effect on the Company’s operations and financial results. The following table summarizes the preliminary calculation of the gains associated with each transaction as well as the net assets and liabilities that were transferred to the respective buyers and derecognized as of the respective closing dates of the sales of these businesses. UCE UPG Total Sale price $ 11,500 $ 14,471 $ 25,971 Less: Net working capital deficit (1) (648 ) (4,337 ) (4,985 ) Fixed assets 128 — 128 Intangible assets 5,655 — 5,655 Goodwill 1,025 1,357 2,382 Net deferred tax liabilities (92 ) — (92 ) Net assets (liabilities) sold 6,068 (2,980 ) 3,088 Cumulative translation adjustments reclassified from accumulated other comprehensive loss 2,403 — 2,403 Direct and incremental transaction costs 800 75 875 Gains on sale of businesses $ 2,229 $ 17,376 $ 19,605 (1) Net working capital deficit primarily includes deferred revenue partially offset by accounts receivable.

Goodwill & Intangible Assets

Goodwill & Intangible Assets	9 Months Ended
	Sep. 30, 2016
Goodwill and Intangible Assets Disclosure [Abstract]
Goodwill & Intangible Assets	5. Goodwill and Intangible Assets Goodwill As discussed in Note 1, in January 2016 the Company reorganized its reporting structure and began operating as two reportable segments: Software and Demand Response. Accordingly, goodwill was reallocated from the Company's prior reporting units, which were defined as i) North America Software and Services and ii) International, to the new reporting units within the Software and Demand Response segments, as shown in the following table within "transfers". During 2016, the Company sold two business components that were part of the Software segment, as discussed in Note 4 . Goodwill was allocated to these business components based on their fair value relative to the overall reporting unit prior to the divestitures. The following table rolls forward goodwill for the nine months ended September 30, 2016 : EnerNOC, Inc. Demand Response Software Total Goodwill 1 Balance at December 31, 2015 $ 39,747 $ — $ — $ 39,747 Transfers (39,747 ) 27,391 12,356 — Foreign exchange — 918 (25 ) 893 Sale of business components (Note 4) — — (2,382 ) (2,382 ) Balance at September 30, 2016 $ — $ 28,309 $ 9,949 $ 38,258 1 Accumulated impairment losses as of December 31, 2015 and September 30, 2016 was $108,763 . The Company tests goodwill for impairment at the reporting unit level annually as of November 30. In addition, as part of its ongoing assessment as to the existence of goodwill impairment indicators, the Company considers factors such as updated long-range financial forecasts, current economic conditions, the Company's market capitalization as well as other qualitative factors. As a result of this assessment for the period ended September 30, 2016 , no impairment indicators were identified. In future periods, the Company may be subject to factors that constitute a change in circumstances, indicating that the carrying value of goodwill could exceed fair value. These changes may consist of, but are not limited to, a sustained decline in the Company's market capitalization, reduced future cash flow estimates, an adverse action or assessment by a regulatory agency, and slower growth rates in the Company's industry. Any of these factors, or others, could require the Company to record a charge to earnings in the consolidated financial statements during the period in which any impairment of goodwill is determined, negatively impacting the Company's results of operations. 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, 2016 and December 31, 2015 : As of September 30, 2016 As of December 31, 2015 Gross Carrying Amount Accumulated Amortization Gross Carrying Amount Accumulated Amortization Customer relationships $ 60,635 $ (31,642 ) $ 60,938 $ (26,043 ) Customer contracts 8,228 (7,755 ) 8,042 (6,786 ) Employment and non-compete agreements 2,530 (2,309 ) 3,055 (2,283 ) Software 170 (170 ) 170 (170 ) Developed technology 17,133 (6,492 ) 24,168 (6,867 ) Trade name 1,057 (1,057 ) 1,087 (1,035 ) Patents 180 (117 ) 180 (104 ) Total $ 89,933 $ (49,542 ) $ 97,640 $ (43,288 ) The decrease in the gross carrying amount of intangible assets as of September 30, 2016 as compared to December 31, 2015 , is primarily due to $5,655 of net intangible assets, including gross carrying amounts of $8,804 and accumulated amortization of $3,149 , associated with the UCE business that was sold during the period as discussed in Note 4. Three Months Ended September 30, Nine Months Ended September 30, 2016 2015 2016 2015 Amortization expense included in cost of revenues $ 364 $ 923 $ 1,853 $ 2,848 Amortization expense included in operating expenses 2,150 2,739 6,841 8,759 Total amortization expense $ 2,514 $ 3,662 $ 8,694 $ 11,607 Definite-lived intangible asset lives range from 1 to 15 years and have a weighted average remaining life of 4.6 years at September 30, 2016 . In accordance with ASC 360, Impairment and Disposals of Long-Lived Assets , the Company records impairment losses on long-lived assets, including intangible assets, that are used in operations when events or circumstances indicate that these long-lived assets might be impaired. As a result of the Company’s restructuring actions initiated in the third quarter of 2016, the Company reviewed the undiscounted cash flows and indicators of fair value associated with its intangible assets. Although the Company’s analysis indicated that the fair value of its intangible assets exceeded their carrying amounts as of September 30, 2016, and therefore no impairment charge was required for the current period, changes in circumstances and changes to the Company’s assumptions, estimates, or use of these intangible assets may result in an impairment charge in the near term.

Net Income (Loss) Per Share

Net Income (Loss) Per Share	9 Months Ended
	Sep. 30, 2016
Earnings Per Share [Abstract]
Net Income (Loss) Per Share	6. Net Income (Loss) Per Share The computation of basic and diluted net income (loss) per share is as follows (in thousands, except share and per share information): Three Months Ended September 30, Nine Months Ended September 30, Numerator: 2016 2015 2016 2015 Net income (loss) for basic earnings per share $ 20,625 $ 12,987 $ (19,811 ) $ (56,095 ) ADD: Interest expense related to convertible notes 1,715 2,118 — — Net income (loss) for diluted earnings per share $ 22,340 $ 15,105 $ (19,811 ) $ (56,095 ) Denominator: Basic weighted average common shares outstanding 29,349,772 28,507,939 29,188,693 28,282,647 Weighted average common stock equivalents 399,854 340,707 — — Incremental shares from assumed conversion of convertible notes 4,576,630 5,774,928 — — Diluted weighted average common shares outstanding 34,326,256 34,623,574 29,188,693 28,282,647 Basic net income (loss) per share $ 0.70 $ 0.46 $ (0.68 ) $ (1.98 ) Diluted net income (loss) per share $ 0.65 $ 0.44 $ (0.68 ) $ (1.98 ) Weighted average anti-dilutive shares related to: Incremental shares from assumed conversion of convertible notes — — 4,576,630 5,774,928 Stock options 292,916 473,848 292,749 418,024 Nonvested restricted stock 1,812,661 2,285,100 1,925,246 2,228,630 Restricted stock units 183,668 72,261 658,668 72,261 On May 27, 2015, the Company received stockholder approval to elect to settle conversions of the aggregate outstanding principal amount of its 2.25% convertible senior notes due August 15, 2019 (the Convertible Notes) by paying or delivering cash, shares of common stock or a combination of cash and shares of common stock. However, for purposes of the calculation of diluted net income per share, it is assumed that conversion would be settled entirely in shares of common stock. For the three months ended September 30, 2016 , the Convertible Notes are assumed to be converted as the impact is dilutive. For the nine months ended September 30, 2016 , the Convertible Notes are not assumed to be converted as the impact of conversion is anti-dilutive . For further information regarding the Convertible Notes, please refer to Note 8 . Restricted stock awards are excluded from the calculation of basic weighted-average common shares outstanding until they vest. For restricted stock awards that vest based on achievement of performance conditions, the number of contingently issuable common shares included in diluted weighted-average common shares outstanding is 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, assuming the result would be dilutive. The Company includes 254,654 shares of common stock related to a component of the deferred purchase price consideration for a business acquired in 2011 in the calculation of both the basic and diluted weighted-average common shares outstanding as the shares are not subject to adjustment and the issuance of such shares is not subject to any contingency. These shares are expected to be issued in 2018. The Company excludes common shares held in escrow pursuant to business combinations from the calculation of basic weighted average shares outstanding where the release of such shares is contingent upon an event not solely subject to the passage of time. During the three months ended September 30, 2016, in accordance with a settlement agreement as further described in Note 9, the Company received 87,483 shares of common stock that had been held in escrow related to the acquisition of Pulse Energy Inc. As these shares were delivered to the Company and subsequently retired, they are excluded from basic weighted average shares for the period. As of September 30, 2016, there were no further common shares held in escrow.

Fair Value Measurements

Fair Value Measurements	9 Months Ended
	Sep. 30, 2016
Fair Value Disclosures [Abstract]
Fair Value Measurements	7. Fair Value Measurements The Company measures the fair value of financial instruments pursuant to the guidelines of ASC 820, Fair Value Measurement , which establishes a fair value hierarchy that prioritizes the inputs used to measure fair value. The hierarchy gives the highest priority to quoted market prices in active markets for identical assets and liabilities (Level 1); then to quoted prices for similar instruments in active markets, quoted prices for identical or similar instruments in markets that are not active, and model-based valuation techniques for which all significant assumptions are observable in the market (Level 2); and then to model-based techniques that use significant assumptions that are not observable in the market (Level 3). Financial Instruments and Investments The Company’s financial instruments mainly consist of cash and cash equivalents, restricted cash, accounts receivable and accounts payable. The carrying amounts of such financial instruments approximate their fair value due to their short-term nature. In addition, the Company has long-term investments in non-marketable equity securities that are accounted for as cost-method investments. These investments are not adjusted to fair value on a recurring basis but are periodically assessed for indications of a reduction in fair value that is other-than-temporary. The Company's financial instruments also include its Convertible Notes for which fair value is disclosed. Recurring Fair Value Measurements The table below presents the assets and liabilities measured at fair value on a recurring basis at September 30, 2016 and December 31, 2015 : Fair Value Measured and Recorded Using Totals Quoted Prices in Significant Other (Level 2) Unobservable Inputs (Level 3) As of September 30, 2016 Assets: Money market funds $ 63,331 $ 63,331 $ — $ — As of December 31, 2015 Assets: Money market funds $ 115,847 $ 115,847 $ — $ — Liabilities: Contingent purchase price consideration (1) $ 840 $ — $ — $ 840 (1) The contingent purchase price consideration as of December 31, 2015 relates to the Company’s 2014 acquisition of Activation Energy DSU Limited and was reflected in accrued expense and other current liabilities as of December 31, 2015 . The amount was paid in full in February 2016. The following table rolls forward liabilities measured at fair value on a recurring basis for which the measurement is categorized as Level 3: Liabilities Balance January 1, 2016 $ 840 Cash payment during the period (840 ) Balance September 30, 2016 $ — Non-Recurring Fair Value Measurements Cost method investments and non-financial assets, such as intangible assets, property and equipment, and assets and liabilities held for sale, are adjusted to fair value only if an impairment is recognized. There were no assets or liabilities measured at fair value on a non-recurring basis at either September 30, 2016 or December 31, 2015 . During the three months ended June 30, 2016, the Company recorded an impairment loss of $1,200 , included in "other income (expense), net", to adjust the carrying amount of cost method investments due to a decline in fair value that was deemed to be other-than-temporary. In assessing the fair value of these investments, the Company evaluated all available information, both qualitative and quantitative, including current financial forecasts, recent or pending rounds of financing activity, and other available market data. The fair value of the investments, for which the inputs are categorized as Level 3 on the fair value hierarchy, was determined based on a probability-weighted assessment of liquidation scenarios. As of September 30, 2016 , the carrying value of these investments was $1,300 and no further impairment indicators were noted. As discussed in Note 3, during the second quarter of 2016 the Company recorded a $2,494 impairment charge related to leasehold improvements and furniture and fixtures associated with subleased office space. The fair value of the asset group, for which the inputs are categorized as Level 3 on the fair value hierarchy, was determined based on the discrete cash flows of the asset group and incorporated assumptions relative to how a market participant would value the group. Assets and Liabilities for which Fair Value Disclosure is Required The Company had $126,800 of principal outstanding on its Convertible Notes at September 30, 2016 and December 31, 2015 . The carrying value of the Convertible Notes, which includes the unamortized debt discount and issuance costs, was $114,205 and $111,254 as of September 30, 2016 and December 31, 2015 , respectively, and the fair value of the Convertible Notes was approximately $91,930 and $73,624 as of September 30, 2016 and December 31, 2015 , respectively. The fair value was determined based on the quoted market price of the Convertible Notes as of those dates and is classified as a Level 1 measurement.

Borrowings and Credit Arrangeme

Borrowings and Credit Arrangements (Notes)	9 Months Ended
	Sep. 30, 2016
Debt Disclosure [Abstract]
Borrowings and Credit Arrangements	8. Borrowings and Credit Arrangements Credit Agreement In August 2014, the Company entered into a $30,000 senior secured revolving credit facility (the 2014 credit facility) with Silicon Valley Bank (SVB) pursuant to a loan and security agreement, as amended, which is available for issuances of letters of credit and revolving loans. In August 2016, the Company and SVB entered into a third amendment to the 2014 credit facility for a fee of $75 to extend the maturity date from August 9, 2016 to August 8, 2017. The 2014 credit facility is subject to continued covenant compliance and borrowing base requirements. As of September 30, 2016 , the Company was in compliance with all of its covenants, had no outstanding borrowings and had outstanding letters of credit totaling $23,287 under the 2014 credit facility. As of September 30, 2016 , there was $6,713 available under the 2014 credit facility for future borrowings or additional issuances of letters of credit. In the event of termination or default, the Company may be required to cash collateralize any outstanding letters of credit up to 105% of their face amount. Convertible Notes On August 12, 2014, the Company sold $160,000 aggregate principal amount of Convertible Notes due August 15, 2019. The Convertible Notes include customary terms and covenants, including certain events of default after which they may be declared or become due and payable immediately. The Convertible Notes are convertible at an initial conversion rate of 36.0933 shares of common stock per $1 principal amount (equivalent to an initial conversion price of approximately $27.71 per share of common stock). The Company may elect to settle conversions by paying or delivering, as the case may be, cash, shares of common stock or a combination of cash and shares of common stock. Upon issuance, the Company accounted for the liability and equity components of the Convertible Notes separately to reflect a non-convertible 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 proceeds of $22,570 were allocated to the conversion feature (equity component) with a corresponding offset recognized as a discount to reduce the net carrying value. In addition, debt issuance costs were allocated to the liability and equity components. The amounts allocated to the liability component are included as part of the debt discount, which 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 December 2015, in privately negotiated transactions, the Company repurchased in cash $33,200 in aggregate principal amount of the outstanding Convertible Notes for a total purchase price of $19,733 plus accrued interest. The consideration was allocated to the fair value of the liability component of the repurchased Convertible Notes immediately before extinguishment. Following the repurchases, the remaining principal outstanding was $126,800 . The following table shows the gross and net carrying amount of the Convertible Notes at September 30, 2016 and December 31, 2015 : September 30, 2016 December 31, 2015 Convertible Notes, principal amount $ 126,800 $ 126,800 Less: debt discount and issuance costs (12,595 ) (15,546 ) Convertible Notes, net $ 114,205 $ 111,254 Interest expense under the Convertible Notes is as follows: Three Months Ended September 30, Nine Months Ended September 30, 2016 2015 2016 2015 Accretion of debt discount and issuance costs $ 1,002 $ 1,218 $ 2,951 $ 3,571 2.25% accrued interest 713 900 2,131 2,680 Total interest expense from Convertible Notes $ 1,715 $ 2,118 $ 5,082 $ 6,251

Commitments and Contingencies

Commitments and Contingencies	9 Months Ended
	Sep. 30, 2016
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies	9. Commitments and Contingencies Performance Guarantees 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, 2016 were $21,790 and included deposits held by certain customers of $212 . These amounts primarily represent upfront 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 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, 2016 , the Company had $600 in deferred fees for these arrangements, which were included in deferred revenues. As of September 30, 2016 , 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 $3,364 . Lease Arrangements The Company leases office space under various operating leases. The Company has entered into sublease arrangements for certain excess space related to these leased facilities. As of September 30, 2016 , future non-cancelable sublease payments were $7,964 over the next four years. Contingencies and Indemnifications 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. No lawsuit has been filed and 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 a loss may have been incurred related to this matter. The potential amount of such a loss is not currently estimable because the matter involves unresolved questions of fact. In August 2016, a former employee filed a complaint and demand for a trial jury in state court in the Commonwealth of Massachusetts against the Company related to the payment of commissions and other claims. In September 2016, the Company answered the complaint, denying the claims. 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 a loss may have been incurred related to this matter. The potential amount of such a loss is not currently estimable because the matter is in its early stages and involves unresolved questions of fact. Escrow Settlement On July 27, 2016, the Company and the former shareholders of Pulse Energy Inc. (Pulse) reached a settlement with respect to claims made by the Company related to certain general representations and warranties made by the former shareholders related to the stock purchase agreement pursuant to which the Company acquired Pulse in December 2014. In accordance with the settlement agreement, $2,900 of the cash and 87,483 shares of the Company's common stock that were held in escrow as security for indemnification obligations were released to the Company in settlement of the claims. As a result, the Company recorded a gain of $3,535 for the three and nine months ended September 30, 2016 , which is included in the consolidated statement of operations within general and administrative expenses. The gain includes the $2,900 of cash and $635 , which represents the fair value of the 87,483 common shares as of the date of the settlement. The fair value of the shares, which were subsequently retired, was recorded as an adjustment to additional paid-in capital. General Contingencies 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 such matters to have a material adverse effect on its consolidated financial condition, results of operations or cash flows.

Stockholders' Equity

Stockholders' Equity	9 Months Ended
	Sep. 30, 2016
Equity [Abstract]
Stockholders' Equity	10. Stockholder's Equity Stock-Based Compensation The Company grants share-based awards to employees, consultants, members of the board of directors and advisory board members. 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. Stock-based compensation recorded in the consolidated statements of operations was as follows: Three Months Ended September 30, Nine Months Ended September 30, 2016 2015 2016 2015 Selling and marketing $ 975 $ 1,243 $ 2,767 $ 3,194 General and administrative 2,147 2,061 6,466 7,187 Research and development 330 351 1,003 1,004 Total stock-based compensation (1) $ 3,452 $ 3,655 $ 10,236 $ 11,385 (1) Stock-based compensation expense for the three and nine months ended September 30, 2015 includes $2 and $495 related to the Company's acquisition of World Energy Solutions, Inc. that was settled with equivalent cash payments. The Company’s Chief Executive Officer is required to receive his performance-based bonus, if achieved, in shares of the Company's common stock. During the nine months ended September 30, 2016 and 2015 , the Company recorded $324 and $380 of stock based compensation, respectively, related to this performance based bonus. Stock Options The following is a summary of the Company’s stock option activity during the nine months ended September 30, 2016 : Nine Months Ended September 30, Number of Shares Underlying Options Weighted- Average Exercise Price Per Share Aggregate Intrinsic Value Weighted Average Remaining Life (in years) Outstanding at December 31, 2015 610,855 $ 18.93 Granted — — Exercised (19,426 ) 0.51 Cancelled (206,074 ) 25.20 Outstanding at September 30, 2016 385,355 $ 16.52 $ 452 Exercisable at end of period 379,249 $ 16.60 $ 452 1.6 Vested or expected to vest at September 30, 2016 384,818 $ 16.52 $ 452 1.6 The aggregate intrinsic value as of September 30, 2016 in the preceding table represents the total pre-tax intrinsic value, based on the Company's closing stock price of $5.41 on September 30, 2016 , that would have been received by the option holders had all option holders exercised their "in-the-money" options as of that date. The total number of shares issuable upon the exercise of "in-the-money" options exercisable as of September 30, 2016 was approximately 92,241 . The total intrinsic value of options exercised during the nine months ended September 30, 2016 was $127 . For unvested stock options outstanding as of September 30, 2016 , the Company had $52 of unrecognized stock-based compensation, which is expected to be recognized over a weighted average period of 1.3 years. Restricted Stock The following table summarizes the Company’s restricted stock activity during the nine months ended September 30, 2016 : Number of Shares Weighted Average Grant Date Fair Value Per Share Nonvested at December 31, 2015 2,294,691 $ 14.20 Granted 935,355 6.87 Vested (857,303 ) 13.50 Cancelled (391,599 ) 11.97 Nonvested at September 30, 2016 1,981,144 $ 11.48 For unvested restricted stock outstanding as of September 30, 2016 , the Company had $16,222 of unrecognized stock-based compensation expense, which is expected to be recognized over a weighted average period of 2.1 years. Restricted Stock Units The following table summarizes the Company’s restricted stock unit activity during the nine months ended September 30, 2016 : Number of Shares Weighted Average Grant Date Fair Value Per Share Nonvested at December 31, 2015 258,983 $ 15.27 Granted 710,750 6.15 Vested (87,136 ) 7.39 Cancelled (185,230 ) 9.78 Nonvested at September 30, 2016 697,367 $ 8.42 For non-vested restricted stock units subject to service-based vesting conditions outstanding as of September 30, 2016 , the Company had $2,976 of unrecognized stock-based compensation, which is expected to be recognized over a weighted average period of 2.4 years. For non-vested restricted stock units subject to outstanding performance-based vesting conditions that were not probable of vesting at September 30, 2016 , the Company had $1,423 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 stock-based compensation. Employee Stock Purchase Plan On May 26, 2016, the Company's shareholders approved an employee stock purchase plan (the 2016 ESPP). The 2016 ESPP permits eligible employees, through payroll withholdings, to purchase shares of the Company's common stock at a 15% discount from the fair market value of the stock as determined on specific dates at six month intervals. The maximum amount of shares issuable under the 2016 ESPP is 3,000,000 . In any six month period, the maximum amount of shares issuable is limited to 500 shares per participant and 350,000 shares for all participants. No offerings are expected to be made under the ESPP during 2016. Share Repurchase Activity In connection with the vesting of restricted stock and restricted stock units under its equity incentive plans, the Company withheld 302,301 shares of its common stock during the nine months ended September 30, 2016 to satisfy employee minimum statutory income tax withholding obligations 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 Company's equity incentive plans. Accumulated Other Comprehensive Income (Loss) Changes in accumulated other comprehensive income (loss), which are entirely comprised of foreign currency translation adjustments, net of tax, are as follows: Foreign Currency Translation Adjustments Balance at December 31, 2015 $ 8,524 Other comprehensive loss (income) before reclassifications (2,331 ) Reclassification due to liquidation of a foreign entity (Note 4) (2,403 ) Balance at September 30, 2016 $ 3,790

Income Taxes

Income Taxes	9 Months Ended
	Sep. 30, 2016
Income Tax Disclosure [Abstract]
Income Taxes	11. 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 months ended September 30, 2016 , 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 worldwide income tax expense of $689 and $1,271 for the three and nine months ended September 30, 2016 , respectively. The income tax expense for the nine months ended September 30, 2016 is driven by the mix of earnings from foreign operations and reflects changes relating to valuation allowances associated with deferred tax assets for certain foreign entities. The Company recorded an income tax expense of $417 and an income tax benefit of $1,523 for the three and nine months ended September 30, 2015 , respectively, which included a $2,268 benefit during the nine months ended September 30, 2015 due to the release of a portion of a U.S. valuation allowance in connection with the World Energy Solutions, Inc. acquisition. 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 months ended September 30, 2016 , there were no material changes in the Company’s uncertain tax positions. The Company reviews all available evidence to evaluate the recovery of deferred tax assets, including the recent history of losses in all tax jurisdictions, as well as its ability to generate income in future periods. As of September 30, 2016 , due to the uncertainty around the realizability of certain domestic and foreign deferred tax assets, the Company continues to maintain a valuation allowance.

Concentrations of Credit Risk

Concentrations of Credit Risk	9 Months Ended
	Sep. 30, 2016
Risks and Uncertainties [Abstract]
Concentrations of Credit Risk	12. Concentration of Credit Risk For the three and nine months ended September 30, 2016, the Company had a large concentration of revenue with PJM Interconnection (PJM). PJM is an electric power grid operator in the mid-Atlantic region 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. Revenues from PJM are included within the Demand Response operating segment. No other customer represented more than 10% of consolidated revenue for the three and nine months ended September 30, 2016 and 2015. The following table presents PJM revenues for the three and nine months ended September 30, 2016 and 2015 : Three Months Ended September 30, 2016 2015 Revenues % of Total Revenues % of Total PJM $ 94,398 56 % $ 143,804 66 % Nine Months Ended September 30, 2016 2015 Revenues % of Total Revenues % of Total PJM $ 179,179 51 % $ 161,618 47 % The Company has accounts receivable balances from certain customers that represent more than 10% of the Company's total accounts receivable balance of September 30, 2016 . These customers include Southern California Edison and Korea Power Exchange representing 12% and 11% of total accounts receivable, respectively. The Company currently participates in three PJM programs, which the Company refers to as Limited, Extended and Annual. Each program has a different delivery period, but the Company receives payments for all three programs ratably throughout PJM’s fiscal year, which ends May 31. The delivery period for the Limited program is June through September. The delivery period for the Extended program is June through October and then the following May. The delivery period for the Annual program is June through May. In all three programs, revenues earned could potentially be subject to retroactive adjustment or refund based on performance during the delivery period and, therefore, the price is not considered fixed or determinable until the end of the program period. Accordingly, revenues from all three programs are deferred and recognized at the end of the applicable delivery period. In the case of the Limited program, because the delivery period ends before the end of PJM’s fiscal year, throughout which the Company receives payments, a portion of the revenues earned are recorded and accrued as unbilled revenue. Unbilled revenue related to PJM was $69,838 and $68,859 at September 30, 2016 and December 31, 2015 , respectively. In the event the Company completely eliminates its obligation in a program through portfolio management, including participation in PJM incremental auctions, revenues related to such activity are recognized at the beginning of the delivery period.

Recent Accounting Pronouncement

Recent Accounting Pronouncements	9 Months Ended
	Sep. 30, 2016
Accounting Changes and Error Corrections [Abstract]
Recent Accounting Pronouncements	13. Recent Accounting Pronouncements In May 2014, the FASB issued ASU 2014-09, Revenue from Contracts with Customers (Topic 606) (ASU 2014-09). ASU 2014-09 provides that revenue should be recognized when an entity transfers promised goods or services to customers in an amount that reflects the consideration to which the entity expects to be entitled in exchange for those goods or services. In addition, the standard requires disclosure of the nature, amount, timing and uncertainty of revenue and cash flow arising from contracts with customers. The FASB has issued several amendments and updates to the new revenue standard, including guidance related to when an entity should recognize revenue gross as a principal or net as an agent and how an entity should identify performance obligations. As amended, the new guidance is effective for annual and interim periods beginning after December 15, 2017, with early adoption permitted no earlier than the original effective date of the standard, which is the first quarter of fiscal 2017 for the Company. The new guidance allows for full retrospective adoption applied to all periods presented or a modified retrospective adoption with the cumulative effect of initially applying the new guidance recognized at the date of initial application. The Company is continuing to evaluate the future impact and method of adoption of ASU 2014-09 and related amendments on its consolidated financial statements and related disclosures. The Company is considering early adoption of the new standard using the modified retrospective method in the first quarter of 2017. The Company's ability to early adopt the standard is dependent on system readiness and the completion of analysis necessary to meet the requirements under ASU 2014-09. While management continues to assess all potential impacts of the new standard, the Company currently believes that the most significant impact of adoption relates to the enhanced level of disclosures related to revenue from contracts with customers, the accounting for demand response programs, and the timing of revenue recognition related to procurement auctions. The Company anticipates that revenue for certain demand response programs, for which revenue is currently deferred until the end of the program period, will be recognized ratably over the program delivery period under the new revenue guidance. The Company also anticipates that revenue for certain procurement auctions, for which revenue is currently recognized as fees become payable based on energy usage, will be recognized when the Company's performance obligation relative to the auction is complete. In August 2014, the FASB issued 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). ASU 2014-15 requires that the Company evaluate, 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 and interim periods ending after December 15, 2016, and early adoption is permitted. The Company does not expect to early adopt ASU 2014-15 and does not believe the standard will have a material impact on its consolidated financial statements and related disclosures. In January 2016, the FASB issued ASU 2016-01, Recognition and Measurement of Financial Assets and Financial Liabilities (ASU 2016-01), which provides new guidance on the recognition and measurement of financial assets and financial liabilities. ASU 2016-01 will impact the accounting for equity investments and financial liabilities under the fair value option, and the presentation and disclosure requirements for financial instruments. All equity investments in unconsolidated entities (other than those accounted for under the equity method of accounting) will generally be measured at fair value with changes in fair value recognized in earnings. There will no longer be an "available-for-sale" classification for equity securities with readily determinable fair values. In general, the new guidance will require modified retrospective application to all outstanding instruments, with a cumulative effect adjustment recorded to opening retained earnings. This guidance is effective January 1, 2018. The Company is currently evaluating the effect of this standard on its consolidated financial statements and related disclosures. In February 2016, the FASB issued ASU 2016-02, Leases (ASU 2016-02). ASU 2016-02 requires lessees to recognize the assets and liabilities on their balance sheet for the rights and obligations created by most leases and continue to recognize expenses on their income statements over the lease term. The standard will also require disclosures designed to give financial statement users information on the amount, timing, and uncertainty of cash flows arising from leases. The guidance is effective for annual reporting periods beginning after December 15, 2018 and interim periods within those fiscal years, with early adoption permitted. The Company does not anticipate that it will early adopt the new standard. The Company is currently evaluating the effect of the standard on its consolidated financial statements and related disclosures. In March 2016, the FASB issued ASU 2016-09, Improvements to Employee Share-Based Payment Accounting (ASU 2016-09). ASU 2016-09 simplifies several aspects of the accounting for share-based payment award transactions, including income tax consequences, classification of awards as either equity or liabilities, and classification on the statement of cash flows. ASU 2016-09 is effective for the Company's fiscal year ending December 31, 2017 and interim periods therein. While the Company is continuing to evaluate the impact of the standard on its consolidated financial statements and related disclosures, the Company does not expect that the adoption of the new standard in 2017 will have a significant impact on its provision for income taxes or cash flow presentation. In August 2016, the FASB issued ASU 2016-15, Classification of Certain Cash Receipts and Cash Payments (ASU 2016-15). ASU 2016-15 provides guidance on the classification of certain transactions in the statement of cash flows, such as contingent consideration payments made in connection with a business combination and debt prepayment or extinguishment costs. The new guidance is effective for the Company's fiscal year ending December 31, 2018 and interim periods therein and early adoption is permitted. When adopted, the new guidance will be applied retrospectively. The Company expects that the adoption of ASU 2016-15 will primarily impact the cash flow classification of payments related to contingent consideration from business combinations and changes in restricted cash.

Description of Business and B20

Description of Business and Basis of Presentation (Policies)	9 Months Ended
	Sep. 30, 2016
Accounting Policies [Abstract]
Description Of Business	Description of Business EnerNOC, Inc. (the Company) is a leading provider of energy intelligence software (EIS) and demand response solutions to enterprises, utilities, and electric power grid operators. The Company’s EIS provides enterprises with a Software-as-a-Service (SaaS) energy management application that enables them to better manage and control energy costs for their organizations. The Company offers premium professional services that support the implementation of its EIS and help its enterprise customers set their energy management strategy. The Company's professional services offerings also include energy audits and retro-commissioning. The Company’s demand response solutions provide utilities and electric power grid operators with a managed service demand response resource that matches obligation in the form of megawatts (MWs) that the Company agrees to deliver to utilities and/or electric power grid operators, with supply, in the form of MWs that are curtailed from the electric power grid through the Company's arrangements with commercial and industrial end-users of energy (C&I end-users). The Company’s demand response solutions are also capable of providing utilities with the underlying technology to manage their own utility-sponsored demand response programs and secure reliable demand-side resources.
Basis of Consolidation	Basis of Presentation The accompanying unaudited condensed consolidated financial statements of the Company include the accounts of its wholly-owned subsidiaries and have been prepared by the Company in accordance with accounting principles generally accepted in the United States (GAAP) for interim financial information pursuant to Rule 10-01 of Regulation S-X. Accordingly, they do not include all of the information and notes required by GAAP for complete financial statements. Intercompany transactions and balances are eliminated in consolidation. 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 unaudited condensed consolidated financial statements and accompanying notes. The Company owns 60% of EnerNOC Japan K.K., for which it consolidates the results of operations and financial position in the accompanying financial statements. The remaining 40% represents a noncontrolling interest in the accompanying unaudited condensed consolidated balance sheets and statements of operations.
Use of Estimates in Preparation of Financial Statements	Use of Estimates The preparation of financial statements in conformity with 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, expected future cash flows used to evaluate the recoverability of long-lived assets, amortization methods and periods, valuation of cost-method investments, certain accrued expenses and other related charges, stock-based compensation, contingent liabilities, tax reserves and the 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, may vary from these estimates.
Significant Accounting Policies	Summary of Significant Accounting Policies The Company’s significant accounting policies are described in Note 1, “Description of Business, Basis of Presentation and Summary of Significant Accounting Policies,” in the Company’s Annual Report on Form 10-K for the fiscal year ended December 31, 2015 (2015 Form 10-K).
Recent Accounting Pronouncements	In May 2014, the FASB issued ASU 2014-09, Revenue from Contracts with Customers (Topic 606) (ASU 2014-09). ASU 2014-09 provides that revenue should be recognized when an entity transfers promised goods or services to customers in an amount that reflects the consideration to which the entity expects to be entitled in exchange for those goods or services. In addition, the standard requires disclosure of the nature, amount, timing and uncertainty of revenue and cash flow arising from contracts with customers. The FASB has issued several amendments and updates to the new revenue standard, including guidance related to when an entity should recognize revenue gross as a principal or net as an agent and how an entity should identify performance obligations. As amended, the new guidance is effective for annual and interim periods beginning after December 15, 2017, with early adoption permitted no earlier than the original effective date of the standard, which is the first quarter of fiscal 2017 for the Company. The new guidance allows for full retrospective adoption applied to all periods presented or a modified retrospective adoption with the cumulative effect of initially applying the new guidance recognized at the date of initial application. The Company is continuing to evaluate the future impact and method of adoption of ASU 2014-09 and related amendments on its consolidated financial statements and related disclosures. The Company is considering early adoption of the new standard using the modified retrospective method in the first quarter of 2017. The Company's ability to early adopt the standard is dependent on system readiness and the completion of analysis necessary to meet the requirements under ASU 2014-09. While management continues to assess all potential impacts of the new standard, the Company currently believes that the most significant impact of adoption relates to the enhanced level of disclosures related to revenue from contracts with customers, the accounting for demand response programs, and the timing of revenue recognition related to procurement auctions. The Company anticipates that revenue for certain demand response programs, for which revenue is currently deferred until the end of the program period, will be recognized ratably over the program delivery period under the new revenue guidance. The Company also anticipates that revenue for certain procurement auctions, for which revenue is currently recognized as fees become payable based on energy usage, will be recognized when the Company's performance obligation relative to the auction is complete. In August 2014, the FASB issued 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). ASU 2014-15 requires that the Company evaluate, 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 and interim periods ending after December 15, 2016, and early adoption is permitted. The Company does not expect to early adopt ASU 2014-15 and does not believe the standard will have a material impact on its consolidated financial statements and related disclosures. In January 2016, the FASB issued ASU 2016-01, Recognition and Measurement of Financial Assets and Financial Liabilities (ASU 2016-01), which provides new guidance on the recognition and measurement of financial assets and financial liabilities. ASU 2016-01 will impact the accounting for equity investments and financial liabilities under the fair value option, and the presentation and disclosure requirements for financial instruments. All equity investments in unconsolidated entities (other than those accounted for under the equity method of accounting) will generally be measured at fair value with changes in fair value recognized in earnings. There will no longer be an "available-for-sale" classification for equity securities with readily determinable fair values. In general, the new guidance will require modified retrospective application to all outstanding instruments, with a cumulative effect adjustment recorded to opening retained earnings. This guidance is effective January 1, 2018. The Company is currently evaluating the effect of this standard on its consolidated financial statements and related disclosures. In February 2016, the FASB issued ASU 2016-02, Leases (ASU 2016-02). ASU 2016-02 requires lessees to recognize the assets and liabilities on their balance sheet for the rights and obligations created by most leases and continue to recognize expenses on their income statements over the lease term. The standard will also require disclosures designed to give financial statement users information on the amount, timing, and uncertainty of cash flows arising from leases. The guidance is effective for annual reporting periods beginning after December 15, 2018 and interim periods within those fiscal years, with early adoption permitted. The Company does not anticipate that it will early adopt the new standard. The Company is currently evaluating the effect of the standard on its consolidated financial statements and related disclosures. In March 2016, the FASB issued ASU 2016-09, Improvements to Employee Share-Based Payment Accounting (ASU 2016-09). ASU 2016-09 simplifies several aspects of the accounting for share-based payment award transactions, including income tax consequences, classification of awards as either equity or liabilities, and classification on the statement of cash flows. ASU 2016-09 is effective for the Company's fiscal year ending December 31, 2017 and interim periods therein. While the Company is continuing to evaluate the impact of the standard on its consolidated financial statements and related disclosures, the Company does not expect that the adoption of the new standard in 2017 will have a significant impact on its provision for income taxes or cash flow presentation. In August 2016, the FASB issued ASU 2016-15, Classification of Certain Cash Receipts and Cash Payments (ASU 2016-15). ASU 2016-15 provides guidance on the classification of certain transactions in the statement of cash flows, such as contingent consideration payments made in connection with a business combination and debt prepayment or extinguishment costs. The new guidance is effective for the Company's fiscal year ending December 31, 2018 and interim periods therein and early adoption is permitted. When adopted, the new guidance will be applied retrospectively. The Company expects that the adoption of ASU 2016-15 will primarily impact the cash flow classification of payments related to contingent consideration from business combinations and changes in restricted cash.

Segment Information (Tables)

Segment Information (Tables)	9 Months Ended
	Sep. 30, 2016
Segment Reporting [Abstract]
Reconciliation of Revenue from Segments	The following table presents segment revenue and segment adjusted EBITDA, along with the reconciliation of segment adjusted EBITDA to consolidated income (loss) before income tax: Three Months Ended September 30, Nine Months Ended September 30, Revenues: 2016 2015 2016 2015 Software Subscription software $ 7,221 $ 4,916 $ 18,966 $ 14,234 Procurement solutions 9,840 8,398 27,568 25,874 Professional services 1,668 4,714 5,460 15,245 Total Software Revenue 18,729 18,028 51,994 55,353 Demand Response Grid operator 121,500 171,928 252,985 237,281 Utility 27,552 27,368 48,876 47,741 Total Demand Response Revenue 149,052 199,296 301,861 285,022 Consolidated Revenue $ 167,781 $ 217,324 $ 353,855 $ 340,375
Reconciliation of Segment Adjusted EBITDA	Three Months Ended September 30, Nine Months Ended September 30, 2016 2015 2016 2015 Segment Adjusted EBITDA: Software adjusted EBITDA $ (10,583 ) $ (13,842 ) $ (48,620 ) $ (49,088 ) Demand Response adjusted EBITDA 46,299 49,433 70,780 56,630 Total Segment adjusted EBITDA 35,716 35,591 22,160 7,542 Reconciliation to consolidated income (loss) before income tax Corporate unallocated expenses (4,239 ) (3,884 ) (14,446 ) (12,043 ) Depreciation, amortization and asset impairments (1) (7,418 ) (9,511 ) (25,888 ) (29,259 ) Stock-based compensation (3,452 ) (3,655 ) (10,236 ) (11,385 ) Restructuring charges (Note 3) (2,933 ) — (6,627 ) — Gains on sale of businesses (Note 4) 2,229 — 19,605 2,991 Direct and incremental (expenses) gains associated with acquisitions, divestitures, reorganizations and settlements (2) 3,525 (70 ) 2,961 (2,913 ) Noncontrolling interest expense (7 ) (23 ) (43 ) (37 ) Interest and other income (expense), net (2,114 ) (5,067 ) (6,069 ) (12,551 ) Consolidated income (loss) before income tax $ 21,307 $ 13,381 $ (18,583 ) $ (57,655 ) (1) Includes impairments of equipment excluded from restructuring charges. (2) Includes expenses that are direct and incremental to business acquisitions and divestitures, including third party professional fees for legal, accounting and valuation services; employee related costs associated with reorganizing the business; and a gain recorded in the three and nine months ended September 30, 2016 associated with the recovery of an escrow settlement claim as further described in Note 9.

Restructuring Activities (Table

Restructuring Activities (Tables)	9 Months Ended
	Sep. 30, 2016
Restructuring and Related Activities [Abstract]
Restructuring and Related Costs	The following table summarizes the current year restructuring activities. These charges are included in "restructuring charges" on the consolidated statements of operations. As discussed in Note 2, these charges are excluded from the Company's segment adjusted EBITDA. Employee Related Contract Terminations Asset Impairments Total Accrued restructuring liability at January 1, 2016 $ — $ — $ — $ — Charges for the three and six months ended June 30, 2016 1,200 — 2,494 3,694 Cash payments (1,082 ) — — (1,082 ) Adjustments for non-cash items — — (2,494 ) (2,494 ) Accrued restructuring liability at June 30, 2016 118 — — 118 Charges for the three months ended September 30, 2016 2,254 679 — 2,933 Cash payments (756 ) (679 ) — (1,435 ) Accrued restructuring liability at September 30, 2016 $ 1,616 $ — $ — $ 1,616 Total restructuring charges for the nine months ended September 30, 2016 $ 3,454 $ 679 $ 2,494 $ 6,627

Gain on Sale of Businesses (Tab

Gain on Sale of Businesses (Tables)	9 Months Ended
	Sep. 30, 2016
Discontinued Operations and Disposal Groups [Abstract]
Disposal Groups, Including Discontinued Operations	UCE UPG Total Sale price $ 11,500 $ 14,471 $ 25,971 Less: Net working capital deficit (1) (648 ) (4,337 ) (4,985 ) Fixed assets 128 — 128 Intangible assets 5,655 — 5,655 Goodwill 1,025 1,357 2,382 Net deferred tax liabilities (92 ) — (92 ) Net assets (liabilities) sold 6,068 (2,980 ) 3,088 Cumulative translation adjustments reclassified from accumulated other comprehensive loss 2,403 — 2,403 Direct and incremental transaction costs 800 75 875 Gains on sale of businesses $ 2,229 $ 17,376 $ 19,605 (1) Net working capital deficit primarily includes deferred revenue partially offset by accounts receivable.

Goodwill & Intangible Assets (T

Goodwill & Intangible Assets (Tables)	9 Months Ended
	Sep. 30, 2016
Goodwill and Intangible Assets Disclosure [Abstract]
Schedule of Changes in Carrying Amount of Goodwill	The following table rolls forward goodwill for the nine months ended September 30, 2016 : EnerNOC, Inc. Demand Response Software Total Goodwill 1 Balance at December 31, 2015 $ 39,747 $ — $ — $ 39,747 Transfers (39,747 ) 27,391 12,356 — Foreign exchange — 918 (25 ) 893 Sale of business components (Note 4) — — (2,382 ) (2,382 ) Balance at September 30, 2016 $ — $ 28,309 $ 9,949 $ 38,258 1 Accumulated impairment losses as of December 31, 2015 and September 30, 2016 was $108,763
Schedule of Finite-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, 2016 and December 31, 2015 : As of September 30, 2016 As of December 31, 2015 Gross Carrying Amount Accumulated Amortization Gross Carrying Amount Accumulated Amortization Customer relationships $ 60,635 $ (31,642 ) $ 60,938 $ (26,043 ) Customer contracts 8,228 (7,755 ) 8,042 (6,786 ) Employment and non-compete agreements 2,530 (2,309 ) 3,055 (2,283 ) Software 170 (170 ) 170 (170 ) Developed technology 17,133 (6,492 ) 24,168 (6,867 ) Trade name 1,057 (1,057 ) 1,087 (1,035 ) Patents 180 (117 ) 180 (104 ) Total $ 89,933 $ (49,542 ) $ 97,640 $ (43,288 )
Acquired Finite-Lived Intangible Assets [Line Items]
Schedule of Acquired Indefinite-lived Intangible Assets by Major Class [Table Text Block]	Three Months Ended September 30, Nine Months Ended September 30, 2016 2015 2016 2015 Amortization expense included in cost of revenues $ 364 $ 923 $ 1,853 $ 2,848 Amortization expense included in operating expenses 2,150 2,739 6,841 8,759 Total amortization expense $ 2,514 $ 3,662 $ 8,694 $ 11,607

Net Income (Loss) Per Share (Ta

Net Income (Loss) Per Share (Tables)	9 Months Ended
	Sep. 30, 2016
Earnings Per Share [Abstract]
Computation of Basic and Diluted Net Income (Loss) per Share	The computation of basic and diluted net income (loss) per share is as follows (in thousands, except share and per share information): Three Months Ended September 30, Nine Months Ended September 30, Numerator: 2016 2015 2016 2015 Net income (loss) for basic earnings per share $ 20,625 $ 12,987 $ (19,811 ) $ (56,095 ) ADD: Interest expense related to convertible notes 1,715 2,118 — — Net income (loss) for diluted earnings per share $ 22,340 $ 15,105 $ (19,811 ) $ (56,095 )
Reconciliation of Basic and Diluted Share Amounts	Denominator: Basic weighted average common shares outstanding 29,349,772 28,507,939 29,188,693 28,282,647 Weighted average common stock equivalents 399,854 340,707 — — Incremental shares from assumed conversion of convertible notes 4,576,630 5,774,928 — — Diluted weighted average common shares outstanding 34,326,256 34,623,574 29,188,693 28,282,647 Basic net income (loss) per share $ 0.70 $ 0.46 $ (0.68 ) $ (1.98 ) Diluted net income (loss) per share $ 0.65 $ 0.44 $ (0.68 ) $ (1.98 ) Weighted average anti-dilutive shares related to: Incremental shares from assumed conversion of convertible notes — — 4,576,630 5,774,928 Stock options 292,916 473,848 292,749 418,024 Nonvested restricted stock 1,812,661 2,285,100 1,925,246 2,228,630 Restricted stock units 183,668 72,261 658,668 72,261

Fair Value Measurements (Tables

Fair Value Measurements (Tables)	9 Months Ended
	Sep. 30, 2016
Fair Value Disclosures [Abstract]
Assets and Liabilities Measured at Fair Value on Recurring Basis	The table below presents the assets and liabilities measured at fair value on a recurring basis at September 30, 2016 and December 31, 2015 : Fair Value Measured and Recorded Using Totals Quoted Prices in Significant Other (Level 2) Unobservable Inputs (Level 3) As of September 30, 2016 Assets: Money market funds $ 63,331 $ 63,331 $ — $ — As of December 31, 2015 Assets: Money market funds $ 115,847 $ 115,847 $ — $ — Liabilities: Contingent purchase price consideration (1) $ 840 $ — $ — $ 840 (1) The contingent purchase price consideration as of December 31, 2015 relates to the Company’s 2014 acquisition of Activation Energy DSU Limited and was reflected in accrued expense and other current liabilities as of December 31, 2015 . The amount was paid in full in February 2016.
Liabilities Measured on Recurring Basis with Unobservable Input Reconciliation	The following table rolls forward liabilities measured at fair value on a recurring basis for which the measurement is categorized as Level 3: Liabilities Balance January 1, 2016 $ 840 Cash payment during the period (840 ) Balance September 30, 2016 $ —

Borrowings and Credit Arrange27

Borrowings and Credit Arrangements (Tables)	9 Months Ended
	Sep. 30, 2016
Debt Disclosure [Abstract]
Convertible Debt	The following table shows the gross and net carrying amount of the Convertible Notes at September 30, 2016 and December 31, 2015 : September 30, 2016 December 31, 2015 Convertible Notes, principal amount $ 126,800 $ 126,800 Less: debt discount and issuance costs (12,595 ) (15,546 ) Convertible Notes, net $ 114,205 $ 111,254
Summary of Interest Expense	Interest expense under the Convertible Notes is as follows: Three Months Ended September 30, Nine Months Ended September 30, 2016 2015 2016 2015 Accretion of debt discount and issuance costs $ 1,002 $ 1,218 $ 2,951 $ 3,571 2.25% accrued interest 713 900 2,131 2,680 Total interest expense from Convertible Notes $ 1,715 $ 2,118 $ 5,082 $ 6,251

Stockholders' Equity (Tables)

Stockholders' Equity (Tables)	9 Months Ended
	Sep. 30, 2016
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 recorded in the consolidated statements of operations was as follows: Three Months Ended September 30, Nine Months Ended September 30, 2016 2015 2016 2015 Selling and marketing $ 975 $ 1,243 $ 2,767 $ 3,194 General and administrative 2,147 2,061 6,466 7,187 Research and development 330 351 1,003 1,004 Total stock-based compensation (1) $ 3,452 $ 3,655 $ 10,236 $ 11,385 (1) Stock-based compensation expense for the three and nine months ended September 30, 2015 includes $2 and $495 related to the Company's acquisition of World Energy Solutions, Inc. that was settled with equivalent cash payments.
Schedule of Share-based Compensation, Stock Options, Activity	The following is a summary of the Company’s stock option activity during the nine months ended September 30, 2016 : Nine Months Ended September 30, Number of Shares Underlying Options Weighted- Average Exercise Price Per Share Aggregate Intrinsic Value Weighted Average Remaining Life (in years) Outstanding at December 31, 2015 610,855 $ 18.93 Granted — — Exercised (19,426 ) 0.51 Cancelled (206,074 ) 25.20 Outstanding at September 30, 2016 385,355 $ 16.52 $ 452 Exercisable at end of period 379,249 $ 16.60 $ 452 1.6 Vested or expected to vest at September 30, 2016 384,818 $ 16.52 $ 452 1.6
Reclassification out of Accumulated Other Comprehensive Income	Changes in accumulated other comprehensive income (loss), which are entirely comprised of foreign currency translation adjustments, net of tax, are as follows: Foreign Currency Translation Adjustments Balance at December 31, 2015 $ 8,524 Other comprehensive loss (income) before reclassifications (2,331 ) Reclassification due to liquidation of a foreign entity (Note 4) (2,403 ) Balance at September 30, 2016 $ 3,790
Restricted Stock [Member]
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, 2016 : Number of Shares Weighted Average Grant Date Fair Value Per Share Nonvested at December 31, 2015 2,294,691 $ 14.20 Granted 935,355 6.87 Vested (857,303 ) 13.50 Cancelled (391,599 ) 11.97 Nonvested at September 30, 2016 1,981,144 $ 11.48
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, 2016 : Number of Shares Weighted Average Grant Date Fair Value Per Share Nonvested at December 31, 2015 258,983 $ 15.27 Granted 710,750 6.15 Vested (87,136 ) 7.39 Cancelled (185,230 ) 9.78 Nonvested at September 30, 2016 697,367 $ 8.42

Concentrations of Credit Risk (

Concentrations of Credit Risk (Tables)	9 Months Ended
	Sep. 30, 2016
Risks and Uncertainties [Abstract]
Concentrations of Credit Risk of Significant Customers	The following table presents PJM revenues for the three and nine months ended September 30, 2016 and 2015 : Three Months Ended September 30, 2016 2015 Revenues % of Total Revenues % of Total PJM $ 94,398 56 % $ 143,804 66 % Nine Months Ended September 30, 2016 2015 Revenues % of Total Revenues % of Total PJM $ 179,179 51 % $ 161,618 47 %

Description of Business and B30

Description of Business and Basis of Presentation - Additional Information (Detail) - Segment	9 Months Ended
	Sep. 30, 2016	Aug. 31, 2016
Accounting Policies [Abstract]
Number of Reporting Units	2
Noncontrolling Interest, Ownership Percentage by Parent	60.00%
Noncontrolling Interest, Ownership Percentage by Noncontrolling Owners	40.00%	9.00%

Segment Information (Details)

Segment Information (Details) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2016USD ($)	Sep. 30, 2015USD ($)	Sep. 30, 2016USD ($)Segment	Sep. 30, 2015USD ($)
Segment Reporting Information
Number of Reporting Units | Segment			2
Segment Reporting, Measurement for Transactions Between Reportable Segments			0
Revenues	$ 167,781	$ 217,324	$ 353,855	$ 340,375
Software
Segment Reporting Information
Revenues	18,729	18,028	51,994	55,353
Software | Subscription software
Segment Reporting Information
Revenues	7,221	4,916	18,966	14,234
Software | Procurement solutions
Segment Reporting Information
Revenues	9,840	8,398	27,568	25,874
Software | Professional services
Segment Reporting Information
Revenues	1,668	4,714	5,460	15,245
Demand Response
Segment Reporting Information
Revenues	149,052	199,296	301,861	285,022
Demand Response | Grid operator
Segment Reporting Information
Revenues	121,500	171,928	252,985	237,281
Demand Response | Utility
Segment Reporting Information
Revenues	$ 27,552	$ 27,368	$ 48,876	$ 47,741

Segment Information Reconciliat

Segment Information Reconciliation of EBITDA to Loss before income tax (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended	9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Jun. 30, 2016	Sep. 30, 2016	Sep. 30, 2015
Segment Reporting, Other Significant Reconciling Item [Line Items]
Stock-based compensation expense	$ 3,452	$ 3,655		$ 10,236	$ 11,385
Restructuring Charges	2,933		$ 3,694
Gains on sale of businesses	2,229	0		19,605	2,991
Net loss attributable to noncontrolling interest	(7)	(23)		(43)	(37)
Income (loss) before income tax	21,307	13,381		(18,583)	(57,655)
Segment Reconciling Items
Segment Reporting, Other Significant Reconciling Item [Line Items]
Segment Adjusted EBITDA	35,716	35,591		22,160	7,542
Corporate unallocated expenses	(4,239)	(3,884)		(14,446)	(12,043)
Depreciation, amortization and asset impairments (1)	(7,418)	(9,511)		(25,888)	(29,259)
Stock-based compensation expense	(3,452)	(3,655)		(10,236)	(11,385)
Restructuring Charges	(2,933)	0		(6,627)	0
Gains on sale of businesses	2,229	0		19,605	2,991
Direct and incremental (expenses) gains associated with acquisitions, divestitures, reorganizations and settlements (2)	3,525	(70)		2,961	(2,913)
Net loss attributable to noncontrolling interest	(7)	(23)		(43)	(37)
Interest and other income (expense), net	(2,114)	(5,067)		(6,069)	(12,551)
Segment Reconciling Items | Software
Segment Reporting, Other Significant Reconciling Item [Line Items]
Segment Adjusted EBITDA	(10,583)	(13,842)		(48,620)	(49,088)
Segment Reconciling Items | Demand Response
Segment Reporting, Other Significant Reconciling Item [Line Items]
Segment Adjusted EBITDA	$ 46,299	$ 49,433		$ 70,780	$ 56,630

Restructuring Activities (Detai

Restructuring Activities (Details) - USD ($)	Sep. 21, 2016	May 23, 2016	Sep. 30, 2016	Jun. 30, 2016	Jun. 30, 2016	Sep. 30, 2016	Dec. 31, 2015
Restructuring Cost and Reserve [Line Items]
Restructuring Charges			$ 2,933,000		$ 3,694,000
Restructuring Reserve			1,616,000	$ 118,000	118,000	$ 1,616,000	$ 0
Loss on Contract Termination			679,000
Asset Impairment Charges				2,494,000
Q2 Restructuring Plan [Member]
Restructuring Cost and Reserve [Line Items]
Workforce Reduction Related to Restructure		5.00%
Severance Costs			271,000			1,146,000
Q3 Restructuring Plan [Member]
Restructuring Cost and Reserve [Line Items]
Workforce Reduction Related to Restructure	15.00%
Severance Costs			1,983,000			1,983,000
Restructuring and Related Cost, Expected Cost			2,200,000			2,200,000
Deferred Bonus [Member] | Q2 Restructuring Plan [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring Charges						325
Employee Severance [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring Charges			2,254,000		1,200,000
Restructuring Reserve			$ 1,616,000	$ 118,000	$ 118,000	$ 1,616,000	$ 0

Restructuring Activities - Roll

Restructuring Activities - Rollforward (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended	9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Jun. 30, 2016	Sep. 30, 2016	Sep. 30, 2015
Restructuring Reserve [Roll Forward]
Beginning balance	$ 118		$ 0	$ 0
Restructuring Charges	2,933		3,694
Cash payments	(1,435)		(1,082)
Adjustments for non-cash items			(2,494)
Ending balance	1,616		118	1,616
Total restructuring charges	2,933	$ 0		6,627	$ 0
Employee Severance [Member]
Restructuring Reserve [Roll Forward]
Beginning balance	118		0	0
Restructuring Charges	2,254		1,200
Cash payments	(756)		(1,082)
Ending balance	1,616		118	1,616
Total restructuring charges				3,454
Contract Termination [Member]
Restructuring Reserve [Roll Forward]
Restructuring Charges	679
Cash payments	$ (679)
Total restructuring charges				679
Asset Impairment [Member]
Restructuring Reserve [Roll Forward]
Restructuring Charges			2,494
Adjustments for non-cash items			$ (2,494)
Total restructuring charges				$ 2,494

Gain on Sale of Businesses (Det

Gain on Sale of Businesses (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015	Aug. 31, 2016
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Noncontrolling Interest, Ownership Percentage by Noncontrolling Owners	40.00%		40.00%		9.00%
Discontinued Operation, Equity Method Investment Retained after Disposal, Ownership Interest after Disposal			0.00%
Proceeds from sale of businesses			$ 23,157	$ 2,991
Reclassification of cumulative translation adjustments due to liquidation of a foreign entity	$ (2,403)	$ 0	(2,403)	0
Gains on sale of businesses	2,229	$ 0	19,605	$ 2,991
Disposal Group, Held-for-sale, Not Discontinued Operations [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Proceeds from sale of businesses			25,971
Net working capital deficit (1)	(4,985)		(4,985)
Fixed assets	128		128
Intangible assets	5,655		5,655
Goodwill	2,382		2,382
Net deferred tax liabilities	(92)		(92)
Net assets (liabilities) sold	3,088		3,088
Reclassification of cumulative translation adjustments due to liquidation of a foreign entity			2,403
Direct and incremental transaction costs			875
Gains on sale of businesses			19,605
UCE Business [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Intangible assets	5,655		5,655
UCE Business [Member] | Disposal Group, Held-for-sale, Not Discontinued Operations [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Proceeds from sale of businesses			11,500
Net working capital deficit (1)	(648)		(648)
Fixed assets	128		128
Goodwill	1,025		1,025
Net deferred tax liabilities	(92)		(92)
Net assets (liabilities) sold	6,068		6,068
Reclassification of cumulative translation adjustments due to liquidation of a foreign entity			2,403
Direct and incremental transaction costs			800
Gains on sale of businesses			2,229
Utility Programs Group [Member] | Disposal Group, Held-for-sale, Not Discontinued Operations [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Disposal Group, Including Discontinued Operation, Accrued Liabilities	286		286
Proceeds from sale of businesses			14,471
Net working capital deficit (1)	(4,337)		(4,337)
Goodwill	1,357		1,357
Net assets (liabilities) sold	$ 2,980		2,980
Reclassification of cumulative translation adjustments due to liquidation of a foreign entity			0
Direct and incremental transaction costs			75
Gains on sale of businesses			$ 17,376

Gain on Sale of Businesses Util

Gain on Sale of Businesses Utility Programs Group (Details) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Aug. 31, 2016
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Noncontrolling Interest, Ownership Percentage by Noncontrolling Owners	40.00%		9.00%
Proceeds from sale of businesses	$ 23,157	$ 2,991
Disposal Group, Held-for-sale, Not Discontinued Operations [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Proceeds from sale of businesses	25,971
UCE Business [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Escrow Deposit	1,500
UCE Business [Member] | Disposal Group, Held-for-sale, Not Discontinued Operations [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Proceeds from sale of businesses	11,500
Utility Programs Group [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Escrow Deposit	1,600
Utility Programs Group [Member] | Disposal Group, Held-for-sale, Not Discontinued Operations [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Proceeds from sale of businesses	14,471
Disposal Group, Including Discontinued Operation, Accrued Liabilities	$ 286

Goodwill Schedule of Changes in

Goodwill Schedule of Changes in Carrying Amount of Goodwill (Details) $ in Thousands	9 Months Ended	12 Months Ended
	Sep. 30, 2016USD ($)Segment	Dec. 31, 2015USD ($)
Goodwill
Number of Reporting Units | Segment	2
Goodwill, Impairment Loss	$ 108,763	$ 108,763
Goodwill [Roll Forward]
Balance at December 31, 2015	39,747
Transfers	0
Foreign exchange	893
Balance at September 30, 2016	38,258	39,747
EnerNOC, Inc [Member]
Goodwill [Roll Forward]
Balance at December 31, 2015	39,747
Transfers	(39,747)
Balance at September 30, 2016	0	39,747
Demand Response
Goodwill [Roll Forward]
Balance at December 31, 2015	0
Transfers	27,391
Foreign exchange	918
Balance at September 30, 2016	28,309	0
Software
Goodwill [Roll Forward]
Balance at December 31, 2015	0
Transfers	12,356
Foreign exchange	(25)
Balance at September 30, 2016	9,949	$ 0
Utility Programs Group [Member]
Goodwill [Roll Forward]
Goodwill, Period Increase (Decrease)	(2,382)
Utility Programs Group [Member] | Software
Goodwill [Roll Forward]
Goodwill, Period Increase (Decrease)	$ (2,382)

Goodwill and Intangible Assets

Goodwill and Intangible Assets Schedule of Finite-Lived Intangible Assets (Details) - USD ($) $ in Thousands	Sep. 30, 2016	Dec. 31, 2015
Finite-Lived Intangible Assets [Line Items]
Finite-Lived Intangible Assets, Gross	$ 89,933	$ 97,640
Finite-Lived Intangible Assets, Accumulated Amortization	49,542	43,288
Customer Relationships [Member]
Finite-Lived Intangible Assets [Line Items]
Finite-Lived Intangible Assets, Gross	60,635	60,938
Finite-Lived Intangible Assets, Accumulated Amortization	31,642	26,043
Customer Contracts [Member]
Finite-Lived Intangible Assets [Line Items]
Finite-Lived Intangible Assets, Gross	8,228	8,042
Finite-Lived Intangible Assets, Accumulated Amortization	7,755	6,786
Employment Agreements And Noncompete Agreements [Member]
Finite-Lived Intangible Assets [Line Items]
Finite-Lived Intangible Assets, Gross	2,530	3,055
Finite-Lived Intangible Assets, Accumulated Amortization	2,309	2,283
Computer Software, Intangible Asset [Member]
Finite-Lived Intangible Assets [Line Items]
Finite-Lived Intangible Assets, Gross	170	170
Finite-Lived Intangible Assets, Accumulated Amortization	170	170
Developed Technology Rights [Member]
Finite-Lived Intangible Assets [Line Items]
Finite-Lived Intangible Assets, Gross	17,133	24,168
Finite-Lived Intangible Assets, Accumulated Amortization	6,492	6,867
Trade Names [Member]
Finite-Lived Intangible Assets [Line Items]
Finite-Lived Intangible Assets, Gross	1,057	1,087
Finite-Lived Intangible Assets, Accumulated Amortization	1,057	1,035
Patents [Member]
Finite-Lived Intangible Assets [Line Items]
Finite-Lived Intangible Assets, Gross	180	180
Finite-Lived Intangible Assets, Accumulated Amortization	$ 117	$ 104

Goodwill and Intangible Asset39

Goodwill and Intangible Assets Additional Information (Details) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2016	Dec. 31, 2015
Finite-Lived Intangible Assets [Line Items]
Finite-Lived Intangible Assets, Gross	$ 89,933	$ 97,640
Finite-Lived Intangible Assets, Accumulated Amortization	$ 49,542	$ 43,288
Minimum [Member]
Finite-Lived Intangible Assets [Line Items]
Finite-Lived Intangible Asset, Useful Life	1 year
Maximum [Member]
Finite-Lived Intangible Assets [Line Items]
Finite-Lived Intangible Asset, Useful Life	15 years
Weighted Average [Member]
Finite-Lived Intangible Assets [Line Items]
Finite-Lived Intangible Asset, Useful Life	4 years 6 months 25 days
UCE Business [Member]
Finite-Lived Intangible Assets [Line Items]
Intangible assets	$ 5,655
Finite-Lived Intangible Assets, Gross	8,804
Finite-Lived Intangible Assets, Accumulated Amortization	3,149
Disposal Group, Held-for-sale, Not Discontinued Operations [Member]
Finite-Lived Intangible Assets [Line Items]
Intangible assets	$ 5,655

Goodwill and Intangible Asset40

Goodwill and Intangible Assets Amortization Expense Schedule (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Acquired Finite-Lived Intangible Assets [Line Items]
Amortization of Intangible Assets	$ 2,514	$ 3,662	$ 8,694	$ 11,607
Cost of Sales [Member]
Acquired Finite-Lived Intangible Assets [Line Items]
Amortization of Intangible Assets	364	923	1,853	2,848
Operating Expense [Member]
Acquired Finite-Lived Intangible Assets [Line Items]
Amortization of Intangible Assets	$ 2,150	$ 2,739	$ 6,841	$ 8,759

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, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Earnings Per Share [Abstract]
Net income (loss) for basic earnings per share	$ 20,625	$ 12,987	$ (19,811)	$ (56,095)
Interest on Convertible Debt, Net of Tax	1,715	2,118	0	0
Net income (loss) for diluted earnings per share	$ 22,340	$ 15,105	$ (19,811)	$ (56,095)

Net Income (Loss) Per Share - R

Net Income (Loss) Per Share - Reconciliation of Basic and Diluted Share Amounts (Detail) - $ / shares	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Antidilutive Securities Excluded from Computation of Earnings Per Share
Basic weighted average common shares outstanding	29,349,772	28,507,939	29,188,693	28,282,647
Weighted average common stock equivalents	399,854	340,707	0	0
Diluted weighted average common shares outstanding	34,326,256	34,623,574	29,188,693	28,282,647
Basic (in dollars per share)	$ 0.70	$ 0.46	$ (0.68)	$ (1.98)
Diluted (in dollars per share)	$ 0.65	$ 0.44	$ (0.68)	$ (1.98)
Weighted average anti-dilutive shares related to:
Incremental shares from assumed conversion of convertible notes	4,576,630	5,774,928	4,576,630	5,774,928
Stock Options
Weighted average anti-dilutive shares related to:
Stock options	292,916	473,848	292,749	418,024
Nonvested Restricted Stock
Weighted average anti-dilutive shares related to:
Stock options	1,812,661	2,285,100	1,925,246	2,228,630
Restricted Stock Units
Weighted average anti-dilutive shares related to:
Stock options	183,668	72,261	658,668	72,261

Net Income (Loss) Per Share (De

Net Income (Loss) Per Share (Detail) $ in Thousands	3 Months Ended	9 Months Ended
	Sep. 30, 2016USD ($)shares	Sep. 30, 2016USD ($)shares	May 27, 2015
Antidilutive Securities Excluded from Computation of Earnings Per Share
Stated Percentage	2.25%	2.25%
Common Stock Received from Escrow Settlement	87,483	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
Stated Percentage			2.25%
Conversion Ratio		36.0933
Convertible Base Principal Amount Of Conversion | $	$ 1	$ 1

Fair Value Measurements - Asset

Fair Value Measurements - Assets and Liabilities Measured at Fair Value on Recurring Basis (Detail) - Fair Value Measurement, Recurring - USD ($) $ in Thousands	Sep. 30, 2016	Dec. 31, 2015
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Money market funds	$ 63,331	$ 115,847
Accrued Acquisition Contingent Consideration Fair Value Disclosure		840
Quoted Prices in Active Markets for Identical Assets (Level 1)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Money market funds	63,331	115,847
Significant Other Observable Inputs (Level 2)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Money market funds	0
Unobservable Inputs (Level 3)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Money market funds	$ 0
Accrued Acquisition Contingent Consideration Fair Value Disclosure		$ 840

Fair Value Measurements - Ass45

Fair Value Measurements - Assets and Liabilities Measured on Recurring Basis with Unobservable Inputs Reconciliation (Detail) $ in Thousands	9 Months Ended
	Sep. 30, 2016USD ($)
Liabilities
Balance January 1, 2016	$ 840
Cash payment during the period	(840)
Balance September 30, 2016	$ 0

Fair Value Measurements (Detail

Fair Value Measurements (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Jun. 30, 2016	Sep. 30, 2016	Dec. 31, 2015
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Cost-method Investments, Realized Gain (Loss)	$ 0		$ 1,200
Asset Impairment Charges		$ 2,494
Convertible Debt, Fair Value Disclosures	91,930		91,930	$ 73,624
Convertible Debt [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Long-term Debt, Gross	126,800		126,800	126,800
Long-term Debt	114,205		114,205	$ 111,254
Fair Value, Measurements, Nonrecurring [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Cost Method Investments	$ 1,300		$ 1,300

Borrowings and Credit Arrange47

Borrowings and Credit Arrangements (Detail) - USD ($)	Aug. 11, 2014	Sep. 30, 2016
Line of Credit Facility
Line of Credit Facility, Collateral Fees, Amount		$ 75
Outstanding borrowings		0
Silicon Valley Bank | 2014 Credit Facility
Line of Credit Facility
Remaining borrowing capacity		6,713,000
Silicon Valley Bank | 2014 Credit Facility | Revolving Credit Facility
Line of Credit Facility
Maximum borrowing capacity	$ 30,000,000
Silicon Valley Bank | 2014 Credit Facility | Letter of Credit
Line of Credit Facility
Outstanding letters of credit		$ 23,287,000
Maximum [Member]
Line of Credit Facility
Default Collateral Percentage	105.00%

Borrowings and Credit Arrange48

Borrowings and Credit Arrangements - Convertible Debt (Detail)	3 Months Ended	9 Months Ended	12 Months Ended
	Sep. 30, 2016USD ($)$ / shares	Sep. 30, 2016USD ($)$ / shares	Dec. 31, 2015USD ($)	May 27, 2015	Aug. 18, 2014USD ($)	Aug. 12, 2014USD ($)
Debt Instrument
Stated Percentage	2.25%	2.25%
Convertible Debt [Member]
Debt Instrument
Long-term Debt, Gross	$ 126,800,000	$ 126,800,000	$ 126,800,000
2.25% Convertible Senior Notes Due 2019
Debt Instrument
Face Amount						$ 160,000,000
Stated Percentage				2.25%
Conversion Ratio		36.0933
Convertible Base Principal Amount Of Conversion	$ 1,000	$ 1,000
Conversion Price | $ / shares	$ 27.71	$ 27.71
Convertible Carrying Amount Of Liability Component					$ 137,430,000
Carrying Amount of Equity Component						$ 22,570,000
Remaining Discount Amortization Period	5 years
Repurchased Face Amount			33,200,000
Repayments of Convertible Debt			$ 19,733,000

Borrowings and Credit Arrange49

Borrowings and Credit Arrangements - Convertible Notes Gross and Carrying Amount Summary (Details) - Convertible Debt [Member] - USD ($) $ in Thousands	Sep. 30, 2016	Dec. 31, 2015
Debt Instrument
Long-term Debt, Gross	$ 126,800	$ 126,800
Debt Instrument, Unamortized Discount (Premium), Net	12,595	15,546
Long-term Debt	$ 114,205	$ 111,254

Borrowings and Credit Arrange50

Borrowings and Credit Arrangements - Interest Expense Schedule (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015	May 27, 2015
Debt Instrument
Stated Percentage	2.25%		2.25%
2.25% Convertible Senior Notes Due 2019
Debt Instrument
Amortization of Debt Discount (Premium)	$ 1,002	$ 1,218	$ 2,951	$ 3,571
Interest Costs Incurred	713	900	2,131	2,680
Interest Expense, Debt	$ 1,715	$ 2,118	$ 5,082	$ 6,251
Stated Percentage					2.25%

Commitments and Contingencies (

Commitments and Contingencies (Detail) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Other Commitments
Gains on sale of businesses	$ 2,229	$ 0	$ 19,605	$ 2,991
Performance guarantees	21,790		21,790
Deposits held by customers	212		212
Deferred fees	600		600
Estimated termination penalty	3,364		3,364
Future minimum sublease rentals	7,964		7,964
Cash Gain (Loss) on Disposition of Business	$ 2,900		$ 2,900
Common Stock Received from Escrow Settlement	87,483		87,483
Noncash Gain (Loss) on Fair Value of Common Stock	$ 635		$ 635
Disposal Group, Held-for-sale or Disposed of by Sale, Not Discontinued Operations [Member] | Pulse Energy [Member] | General and Administrative Expense [Member]
Other Commitments
Gains on sale of businesses	$ (3,535)		$ (3,535)

Stockholders' Equity - Stock Ba

Stockholders' Equity - Stock Based Compensation (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Class of Stock [Line Items]
Stock-based compensation expense	$ 3,452	$ 3,655	$ 10,236	$ 11,385
World Energy Solutions [Member]
Class of Stock [Line Items]
Stock-based compensation expense		2		495
Performance Shares [Member]
Class of Stock [Line Items]
Stock-based compensation expense			324	380
Selling and Marketing Expense [Member]
Class of Stock [Line Items]
Stock-based compensation expense	975	1,243	2,767	3,194
General and Administrative Expense [Member]
Class of Stock [Line Items]
Stock-based compensation expense	2,147	2,061	6,466	7,187
Research and Development Expense [Member]
Class of Stock [Line Items]
Stock-based compensation expense	$ 330	$ 351	$ 1,003	$ 1,004

Stockholders' Equity - Summary

Stockholders' Equity - Summary of Stock Options (Details) $ / shares in Units, $ in Thousands	9 Months Ended
	Sep. 30, 2016USD ($)$ / sharesshares
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding [Roll Forward]
Outstanding at period start (in shares) | shares	610,855
Granted (in shares) | shares	0
Exercised (in shares) | shares	19,426
Cancelled (in shares) | shares	206,074
Outstanding at period end (in shares) | shares	385,355
Exercisable at end of period (in shares) | shares	379,249
Vested or expected to vest at period end (in shares) | shares	384,818
Share-based Compensation Arrangement by Share-based Payment Award, Options, Nonvested, Number of Shares [Roll Forward]
Outstanding at period start (in dollars per share) | $ / shares	$ 18.93
Granted (in dollars per share) | $ / shares	0
Exercised (in dollars per share) | $ / shares	0.51
Cancelled (in dollars per share) | $ / shares	25.20
Outstanding at period end (in dollars per share) | $ / shares	16.52
Exercisable at end of period (in dollars per share) | $ / shares	16.60
Vested or expected to vest at period end (in dollars per share) | $ / shares	$ 16.52
Share-based Compensation Arrangement by Share-based Payment Award, Options, Additional Disclosures [Abstract]
Outstanding at period end | $	$ 452
Exercisable at end of period | $	452
Vested or expected to vest at period end | $	$ 452
Exercisable at end of period (in years)	1 year 7 months
Vested or expected to vest at period end (in years)	1 year 7 months

Stockholders' Equity - Stock Op

Stockholders' Equity - Stock Options (Details) $ / shares in Units, $ in Thousands	9 Months Ended
	Sep. 30, 2016USD ($)$ / sharesshares
Equity [Abstract]
Share Price (in dollars per share) | $ / shares	$ 5.41
Payment Award In-the-money Options Exercisable Number (in shares) | shares	92,241
Exercises in Period, Intrinsic Value	$ 127
Nonvested stock-based compensation expense related to employees	$ 52
Weighted average period of stocks	1 year 3 months 18 days

Stockholders' Equity - Restrict

Stockholders' Equity - Restricted Stock Units and Restricted Stock (Details) $ / shares in Units, $ in Thousands	3 Months Ended	9 Months Ended
	Sep. 30, 2016USD ($)$ / sharesshares	Sep. 30, 2016USD ($)$ / sharesshares
Share-based Compensation Arrangement by Share-based Payment Award
Nonvested stock-based compensation expense related to employees | $	$ 52	$ 52
Weighted average period of stocks		1 year 3 months 18 days
Restricted Stock [Member]
Share-based Compensation Arrangement by Share-based Payment Award
Nonvested stock-based compensation expense related to employees | $	$ 16,222	$ 16,222
Weighted average period of stocks	2 years 1 month 3 days
Number of Shares:
Nonvested at beginning of period | shares		2,294,691
Granted | shares		935,355
Vested | shares		(857,303)
Cancelled | shares		(391,599)
Nonvested at end of period | shares	1,981,144	1,981,144
Weighted Average Grant Date Fair Value Per Share (in dollars per share):
Nonvested at beginning of period | $ / shares		$ 14.20
Granted | $ / shares		6.87
Vested | $ / shares		13.50
Cancelled | $ / shares		11.97
Nonvested at end of period | $ / shares	$ 11.48	$ 11.48
Restricted Stock Units
Share-based Compensation Arrangement by Share-based Payment Award
Nonvested stock-based compensation expense related to employees | $	$ 2,976	$ 2,976
Weighted average period of stocks	2 years 4 months 15 days
Number of Shares:
Nonvested at beginning of period | shares		258,983
Granted | shares		710,750
Vested | shares		(87,136)
Cancelled | shares		(185,230)
Nonvested at end of period | shares	697,367	697,367
Weighted Average Grant Date Fair Value Per Share (in dollars per share):
Nonvested at beginning of period | $ / shares		$ 15.27
Granted | $ / shares		6.15
Vested | $ / shares		7.39
Cancelled | $ / shares		9.78
Nonvested at end of period | $ / shares	$ 8.42	$ 8.42
Restricted Stock Performance Based Vesting Awards Not Probable Vesting [Member]
Share-based Compensation Arrangement by Share-based Payment Award
Nonvested stock-based compensation expense related to employees | $	$ 1,423	$ 1,423

Stockholders' Equity - Employee

Stockholders' Equity - Employee Stock Purchase Plan (Details)	9 Months Ended
	Sep. 30, 2016shares
Employee Stock Ownership Plan (ESOP) Disclosures [Line Items]
Number of Shares Available for Grant (in shares)	3,000,000
Maximum Number of Shares Per Employee (in shares)	500
Number of Shares Available for Grant for A Six Month Period (in shares)	350,000
2016 ESPP [Member]
Employee Stock Ownership Plan (ESOP) Disclosures [Line Items]
Discount from Market Price, Purchase Date	15.00%

Stockholders' Equity - Share Re

Stockholders' Equity - Share Repurchase Activity (Details)	3 Months Ended
	Sep. 30, 2016shares
Common Stock [Member] | 2014 Long-Term Incentive Plan
Class of Stock [Line Items]
Stock repurchased	302,301

Stockholders' Equity - Foreign

Stockholders' Equity - Foreign Currency Translation Reconciliation (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Balance at December 31, 2015			$ 8,524
Other comprehensive loss (income) before reclassifications	$ (575)	$ 2,069	(2,331)	$ 4,719
Reclassification due to liquidation of a foreign entity	(2,403)	$ 0	(2,403)	$ 0
Balance at September 30, 2016	$ 3,790		$ 3,790

Income Taxes (Detail)

Income Taxes (Detail) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Income Tax Disclosure [Abstract]
Provision (benefit) from income taxes	$ 689	$ 417	$ 1,271	$ (1,523)
Benefit from income taxes due to release of portion valuation allowance			$ 2,268

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, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015	Dec. 31, 2015
Concentration Risk
Revenues	$ 167,781	$ 217,324	$ 353,855	$ 340,375
PJM
Concentration Risk
Unbilled revenue	69,838		69,838		$ 68,859
Sales Revenue, Net [Member] | Customer Concentration Risk | PJM
Concentration Risk
Revenues	$ 94,398	$ 143,804	$ 179,179	$ 161,618
Share in accounts receivable from major customers	56.00%	66.00%	51.00%	47.00%
Accounts Receivable [Member] | Customer Concentration Risk | Southern California Edison (SCE) [Member]
Concentration Risk
Share in accounts receivable from major customers	12.00%
Accounts Receivable [Member] | Customer Concentration Risk | Korea Power Exchange (KPW) [Member]
Concentration Risk
Share in accounts receivable from major customers	11.00%
Minimum [Member] | Sales Revenue, Net [Member] | Customer Concentration Risk
Concentration Risk
Share in accounts receivable from major customers			10.00%
Minimum [Member] | Accounts Receivable [Member] | Customer Concentration Risk
Concentration Risk
Share in accounts receivable from major customers			10.00%