Advanced Energy Industries (AEIS) 10-Q 12 Nov 19 2019 Q3 Quarterly report Financial data

Document and Entity Information

Document and Entity Information - shares	9 Months Ended
	Sep. 30, 2019	Nov. 07, 2019
Document and Entity Information
Document Type	10-Q
Document Quarterly Report	true
Document Period End Date	Sep. 30, 2019
Document Transition Report	false
Entity Registrant Name	ADVANCED ENERGY INDUSTRIES INC
Entity Incorporation, State or Country Code	DE
Entity File Number	000-26966
Entity Tax Identification Number	84-0846841
Entity Address, Address Line One	1625 Sharp Point Drive
Entity Address, City or Town	Fort Collins
Entity Address, State or Province	CO
Entity Address, Postal Zip Code	80525
City Area Code	970
Local Phone Number	221-4670
Title of 12(b) Security	Common Stock, $0.001 par value
Trading Symbol	AEIS
Security Exchange Name	NASDAQ
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Large Accelerated Filer
Entity Small Business	false
Entity Emerging Growth Company	false
Entity Shell Company	false
Entity Common Stock, Shares Outstanding		38,331,630
Entity Central Index Key	0000927003
Current Fiscal Year End Date	--12-31
Document Fiscal Year Focus	2019
Document Fiscal Period Focus	Q3
Amendment Flag	false

Condensed Consolidated Balance

Condensed Consolidated Balance Sheets - USD ($) $ in Thousands	Sep. 30, 2019	Dec. 31, 2018
Current assets:
Cash and cash equivalents	$ 340,402	$ 349,301
Marketable securities	747	2,470
Accounts and other receivable, net of allowances of $3,831 and $1,856, respectively	250,151	100,442
Inventories	240,699	97,987
Income taxes receivable	2,124	2,220
Other current assets	45,757	10,173
Current assets from discontinued operations	84	5,855
Total current assets	879,964	568,448
Property and equipment, net	104,568	31,269
Operating lease right-of-use assets	111,193
Deposits and other assets	20,650	6,874
Goodwill	232,200	101,900
Intangible assets, net	189,601	54,910
Deferred income tax assets	56,488	47,099
Non-current assets from discontinued operations	755	5,984
TOTAL ASSETS	1,595,419	816,484
Current liabilities:
Accounts payable	210,647	39,646
Income taxes payable	7,070	13,258
Accrued payroll and employee benefits	48,685	21,775
Other accrued expenses	42,633	22,999
Customer deposits and other	10,804	7,345
Current portion of long-term debt	17,500
Current portion of operating lease liabilities	17,648
Current liabilities from discontinued operations	910	5,286
Total current liabilities	355,897	110,309
LONG-TERM LIABILITIES:
Long-term debt	325,769
Operating lease liabilities	95,101
Deferred income tax liabilities	46,992	6,988
Uncertain tax positions	15,708	14,318
Long-term deferred revenue	8,153	29,108
Other long-term liabilities	86,586	37,744
Non-current liabilities from discontinued operations	1,045	10,715
Total liabilities	935,251	209,182
Commitments and contingencies (Note 19)
Stockholders' equity:
Preferred stock, $0.001 par value, 1,000 shares authorized, none issued and outstanding
Common stock, $0.001 par value, 70,000 shares authorized; 38,332 and 38,164 issued and outstanding, respectively	38	38
Additional paid-in capital	101,757	97,418
Accumulated other comprehensive loss	(9,628)	(3,449)
Retained earnings	567,460	512,783
Advanced Energy stockholders' equity	659,627	606,790
Noncontrolling interest	541	512
Total stockholders' equity	660,168	607,302
TOTAL LIABILITIES AND STOCKHOLDERS' EQUITY	$ 1,595,419	$ 816,484

Condensed Consolidated Balanc_2

Condensed Consolidated Balance Sheets (Parenthetical) - USD ($) $ in Thousands	Sep. 30, 2019	Dec. 31, 2018
Condensed Consolidated Balance Sheets
Accounts receivable, allowances	$ 3,831	$ 1,856
Preferred stock, par value (in dollars per share)	$ 0.001	$ 0.001
Preferred stock, shares authorized (in shares)	1,000	1,000
Preferred stock, shares issued (in shares)	0	0
Preferred Stock, Shares Outstanding	0	0
Common stock, par value (in dollars per share)	$ 0.001	$ 0.001
Common stock, shares authorized (in shares)	70,000,000	70,000,000
Common stock, shares issued (in shares)	38,332,000	38,164,000
Common stock, shares outstanding (in shares)	38,332,000	38,164,000

Condensed Consolidated Statemen

Condensed Consolidated Statements of Operations - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Sales, net:
Total sales, net	$ 175,127	$ 173,082	$ 450,680	$ 564,731
Cost of sales:
Total cost of sales	101,636	87,543	247,323	274,312
Gross profit	73,491	85,539	203,357	290,419
Operating expenses:
Research and development	24,546	18,451	67,675	55,283
Selling, general and administrative	36,401	25,386	93,027	78,792
Amortization of intangible assets	3,002	1,437	6,849	3,958
Restructuring expense	152	403	3,620	403
Total operating expenses	64,101	45,677	171,171	138,436
Operating income	9,390	39,862	32,186	151,983
Other income (expense), net	1,361	401	17,649	(58)
Income from continuing operations, before income taxes	10,751	40,263	49,835	151,925
Provision for income taxes	3,495	5,106	3,819	23,998
Income from continuing operations	7,256	35,157	46,016	127,927
Income (loss) from discontinued operations, net of income taxes	375	(371)	8,690	(226)
Net income	7,631	34,786	54,706	127,701
Income from continuing operations attributable to noncontrolling interest	10	7	29	82
Net income attributable to Advanced Energy Industries, Inc.	$ 7,621	$ 34,779	$ 54,677	$ 127,619
Basic weighted-average common shares outstanding	38,313	38,970	38,258	39,309
Diluted weighted-average common shares outstanding	38,489	39,195	38,457	39,594
Continuing operations: Basic earnings per share	$ 0.19	$ 0.90	$ 1.20	$ 3.25
Continuing operations: Diluted earnings per share	0.19	0.90	1.20	3.23
Discontinued operations: Basic earnings per share	0.01	(0.01)	0.23	(0.01)
Discontinued operations: Diluted earnings per share	0.01	(0.01)	0.23	(0.01)
Basic earnings per share	0.20	0.89	1.43	3.25
Diluted earnings per share	$ 0.20	$ 0.89	$ 1.42	$ 3.23
Product [Member]
Sales, net:
Total sales, net	$ 148,138	$ 144,843	$ 366,443	$ 485,287
Cost of sales:
Total cost of sales	87,536	73,019	204,450	233,778
Service [Member]
Sales, net:
Total sales, net	26,989	28,239	84,237	79,444
Cost of sales:
Total cost of sales	$ 14,100	$ 14,524	$ 42,873	$ 40,534

Condensed Consolidated Statem_2

Condensed Consolidated Statements of Comprehensive Income - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Condensed Consolidated Statements of Comprehensive Income
Net income	$ 7,631	$ 34,786	$ 54,706	$ 127,701
Other comprehensive income:
Foreign currency translation	(4,849)	(735)	(6,281)	(4,679)
Minimum benefit retirement liability, net of income taxes	(92)	(27)	(102)	9
Comprehensive income	2,874	34,078	48,527	123,013
Comprehensive income attributable to noncontrolling interest	10	7	29	82
Comprehensive income attributable to Advanced Energy Industries, Inc.	$ 2,864	$ 34,071	$ 48,498	$ 122,931

Condensed Consolidated Statem_3

Condensed Consolidated Statements of Stockholders' Equity - USD ($) $ in Thousands	Common Stock	Additional Paid-in Capital	Foreign Currency Translation	Minimum Benefit Retirement Liability	Retained Earnings	Non-controlling Interest	Total
Adoption of new accounting standards					$ 19,706		$ 19,706
Beginning Balance at Dec. 31, 2017	$ 40	$ 184,843	$ 4,695	$ (2,162)	333,225		520,641
Beginning Balance (in shares) at Dec. 31, 2017	39,604,000
Non-controlling interest from acquisition						$ 431	431
Stock issued from equity plans		(4,127)					(4,127)
Stock issued from equity plans (in shares)	113,000
Stock-based compensation		4,494					4,494
Stock buyback		(12,750)					(12,750)
Stock buyback (in shares)	(181,000)
Foreign currency translation			2,472				2,472
Minimum benefit retirement liability				(168)			(168)
Net income					46,479
Net Income, Non-controlling Interest						31	46,510
Ending Balance at Mar. 31, 2018	$ 40	172,460	7,167	(2,330)	399,410	462	577,209
Ending Balance (in shares) at Mar. 31, 2018	39,536,000
Beginning Balance at Dec. 31, 2017	$ 40	184,843	4,695	(2,162)	333,225		520,641
Beginning Balance (in shares) at Dec. 31, 2017	39,604,000
Stock buyback							(69,021)
Foreign currency translation							(4,679)
Minimum benefit retirement liability							(9)
Net income							127,619
Net Income, Non-controlling Interest							127,701
Ending Balance at Sep. 30, 2018	$ 39	120,628	16	(2,171)	480,550	513	599,575
Ending Balance (in shares) at Sep. 30, 2018	38,716,000
Beginning Balance at Mar. 31, 2018	$ 40	172,460	7,167	(2,330)	399,410	462	577,209
Beginning Balance (in shares) at Mar. 31, 2018	39,536,000
Stock issued from equity plans		1,552					1,552
Stock issued from equity plans (in shares)	111,000
Stock-based compensation		1,943					1,943
Stock buyback	$ (1)	(25,308)					(25,309)
Stock buyback (in shares)	(407,000)
Foreign currency translation			(6,416)				(6,416)
Minimum benefit retirement liability				132			132
Net income					46,361
Net Income, Non-controlling Interest						44	46,405
Ending Balance at Jun. 30, 2018	$ 39	150,647	751	(2,198)	445,771	506	595,516
Ending Balance (in shares) at Jun. 30, 2018	39,240,000
Stock issued from equity plans		(81)					(81)
Stock issued from equity plans (in shares)	9,000
Stock-based compensation		1,024					1,024
Stock buyback		(30,962)					(30,962)
Stock buyback (in shares)	(533,000)
Foreign currency translation			(735)				(735)
Minimum benefit retirement liability				27			27
Net income					34,779		34,779
Net Income, Non-controlling Interest						7	34,786
Ending Balance at Sep. 30, 2018	$ 39	120,628	16	(2,171)	480,550	513	599,575
Ending Balance (in shares) at Sep. 30, 2018	38,716,000
Beginning Balance at Dec. 31, 2018	$ 38	97,418	(590)	(2,859)	512,783	512	$ 607,302
Beginning Balance (in shares) at Dec. 31, 2018	38,164,000						38,164,000
Stock issued from equity plans		(1,707)					$ (1,707)
Stock issued from equity plans (in shares)	72,000
Stock-based compensation		3,199					3,199
Foreign currency translation			(1,975)				(1,975)
Minimum benefit retirement liability				(53)			(53)
Net income					15,370
Net Income, Non-controlling Interest						8	15,378
Ending Balance at Mar. 31, 2019	$ 38	98,910	(2,565)	(2,912)	528,153	520	622,144
Ending Balance (in shares) at Mar. 31, 2019	38,236,000
Beginning Balance at Dec. 31, 2018	$ 38	97,418	(590)	(2,859)	512,783	512	$ 607,302
Beginning Balance (in shares) at Dec. 31, 2018	38,164,000						38,164,000
Foreign currency translation							$ (6,281)
Minimum benefit retirement liability							102
Net income							54,677
Net Income, Non-controlling Interest							54,706
Ending Balance at Sep. 30, 2019	$ 38	101,757	(6,871)	(2,757)	567,460	541	$ 660,168
Ending Balance (in shares) at Sep. 30, 2019	38,332,000						38,332,000
Beginning Balance at Mar. 31, 2019	$ 38	98,910	(2,565)	(2,912)	528,153	520	$ 622,144
Beginning Balance (in shares) at Mar. 31, 2019	38,236,000
Stock issued from equity plans		665					665
Stock issued from equity plans (in shares)	69,000
Stock-based compensation		937					937
Foreign currency translation			543				543
Minimum benefit retirement liability				63			63
Net income					31,686
Net Income, Non-controlling Interest						11	31,697
Ending Balance at Jun. 30, 2019	$ 38	100,512	(2,022)	(2,849)	559,839	531	656,049
Ending Balance (in shares) at Jun. 30, 2019	38,305,000
Stock issued from equity plans		328					328
Stock issued from equity plans (in shares)	27,000
Stock-based compensation		917					917
Foreign currency translation			(4,849)				(4,849)
Minimum benefit retirement liability				92			92
Net income					7,621		7,621
Net Income, Non-controlling Interest						10	7,631
Ending Balance at Sep. 30, 2019	$ 38	$ 101,757	$ (6,871)	$ (2,757)	$ 567,460	$ 541	$ 660,168
Ending Balance (in shares) at Sep. 30, 2019	38,332,000						38,332,000

Condensed Consolidated Statem_4

Condensed Consolidated Statements of Cash Flows $ in Thousands	9 Months Ended
	Sep. 30, 2019USD ($)	Sep. 30, 2018USD ($)
CASH FLOWS FROM OPERATING ACTIVITIES:
Net income	$ 54,706	$ 127,701
Income from discontinued operations, net of income taxes	8,690	(226)
Income from continuing operations, net of income taxes	46,016	127,927
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	15,301	9,488
Stock-based compensation expense	5,053	7,461
Provision for deferred income taxes	2,825
Gain on sale of central inverter service business	(14,804)
Net loss on disposal of assets	104	167
Changes in operating assets and liabilities, net of assets acquired:
Accounts and other receivable, net	(23,292)	(6,739)
Inventories	(7,217)	(22,132)
Other assets	13,695	717
Accounts payable	23,676	(8,553)
Other liabilities and accrued expenses	(17,779)	49
Income taxes	(14,720)	10,098
Net cash provided by operating activities from continuing operations	28,858	118,483
Net cash provided by (used in) operating activities from discontinued operations	317	(4,550)
Net cash provided by operating activities	29,175	113,933
CASH FLOWS FROM INVESTING ACTIVITIES:
Purchases of marketable securities		(93)
Proceeds from sale of marketable securities	1,742	6
Acquisitions, net of cash acquired	(365,798)	(93,801)
Issuance of notes receivable	(2,800)
Purchases of property and equipment	(15,681)	(16,586)
Net cash used in investing activities from continuing operations	(382,537)	(110,474)
CASH FLOWS FROM FINANCING ACTIVITIES:
Net proceeds from long-term borrowings	347,486
Payments on long-term borrowings	(4,375)
Purchase and retirement of common stock		(69,021)
Net payments related to stock-based award activities	(714)	(2,636)
Net cash provided by (used in) financing activities from continuing operations	342,397	(71,657)
EFFECT OF CURRENCY TRANSLATION ON CASH	(3,185)	(722)
DECREASE IN CASH AND CASH EQUIVALENTS	(14,150)	(68,920)
CASH AND CASH EQUIVALENTS, beginning of period	354,552	415,037
CASH AND CASH EQUIVALENTS, end of period	340,402	346,117
Less cash and cash equivalents from discontinued operations		7,444
CASH AND CASH EQUIVALENTS FROM CONTINUING OPERATIONS, end of period	340,402	338,673
SUPPLEMENTAL DISCLOSURE OF CASH FLOW INFORMATION:
Cash paid for interest	1,049	171
Cash paid for income taxes	15,372	14,180
Cash received for refunds of income taxes	$ 1,537	$ 734

Basis of Presentation

Basis of Presentation	9 Months Ended
	Sep. 30, 2019
Basis of Presentation
BASIS OF PRESENTATION	​ NOTE 1. BASIS OF PRESENTATION Advanced Energy Industries, Inc., a Delaware corporation, and its wholly-owned subsidiaries ("we," "us," "our," "Advanced Energy," or the "Company") design, manufacture, sell and support precision power products that transform, refine, and modify the raw electrical power from the utility and convert it into various types of highly-controllable usable power that is predictable, repeatable and customizable. Our power solutions enable innovation in complex semiconductor and thin film plasma processes such as dry etch, strip, chemical and physical deposition, high and low voltage applications such as process control, analytical instrumentation and medical equipment, and in temperature-critical thermal applications such as material and chemical processing. We also supply related instrumentation products for advanced temperature measurement and control, electrostatic instrumentation products for test and measurement applications, and gas sensing and monitoring solutions for a number of industrial markets. Our network of service support centers provides local repair and field service capability in key regions, provide upgrades and refurbishment services, and sell used equipment to businesses that use our products. In September 2019, we acquired Artesyn Embedded Power business adding new power products and technologies used in networking and computing, data center, and industrial and medical applications. As of December 31, 2015, we discontinued our engineering, production, and sales of our Inverter product line. As such, all Inverter product revenues, costs, assets and liabilities are reported in Discontinued Operations for all periods presented herein, and we currently report as a single unit. See Note 4. Disposed and Discontinued Operations In the opinion of management, the accompanying Unaudited Condensed Consolidated Financial Statements contain all adjustments, consisting of normal, recurring adjustments, necessary to present fairly the financial position of the Company as of September 30, 2019, and the results of our operations and cash flows for the three and nine months ended September 30, 2019 and 2018. The Unaudited Condensed Consolidated Financial Statements included herein have been prepared pursuant to the rules and regulations of the Securities and Exchange Commission ("SEC"). Certain information and footnote disclosures normally included in financial statements prepared in accordance with accounting principles generally accepted in the United States of America ("U.S. GAAP") have been condensed or omitted pursuant to such rules and regulations. These Unaudited Condensed Consolidated Financial Statements should be read in conjunction with the audited Consolidated Financial Statements and Notes thereto contained in our Annual Report on Form 10-K for the fiscal year ended December 31, 2018 and other financial information filed with the SEC. Estimates and Assumptions The preparation of our Consolidated Financial Statements in conformity with U.S. GAAP requires us to make estimates, assumptions and judgments that affect the reported amounts of assets and liabilities, and disclosure of contingent liabilities at the date of the financial statements and the reported amounts of revenue and expenses during the reporting period. We believe that the significant estimates, assumptions, and judgments when accounting for items and matters such as allowances for doubtful accounts, excess and obsolete inventory, warranty reserves, right-of-use assets and related liabilities, acquisitions, asset valuations, asset life, depreciation, amortization, recoverability of assets, impairments, deferred revenue, stock option and restricted stock grants, taxes, and other provisions are reasonable, based upon information available at the time they are made. Actual results may differ from these estimates, making it possible that a change in these estimates could occur in the near term. Critical Accounting Policies Our accounting policies are described in our audited Consolidated Financial Statements and Notes contained in our Annual Report on Form 10-K for the year ended December 31, 2018. See Note 16. Leases New Accounting Standards From time to time, the Financial Accounting Standards Board ("FASB") or other standards setting bodies issue new accounting pronouncements. Updates to the FASB Accounting Standards Codification ("ASC") are communicated through issuance of an Accounting Standards Update ("ASU"). Unless otherwise discussed, we believe that the impact of recently issued guidance, whether adopted or to be adopted in the future, is not expected to have a material impact on the Consolidated Financial Statements upon adoption. Recently issued accounting pronouncements not yet adopted In June 2016, the FASB issued ASU 2016-13, "Financial Instruments—Credit Losses (Topic 326)", Measurement of Credit Losses on Financial Instruments ("ASU 2016-13"). This ASU changes the methodology for measuring credit losses on financial instruments and the timing of when such losses are recorded. ASU 2016-13 is effective for fiscal years, and interim periods within those years, beginning after December 15, 2019. Early adoption is permitted for fiscal years, and interim periods within those years, beginning after December 15, 2018. We are currently assessing the impact ASU 2016-13 will have on our Consolidated Financial Statements. In August 2018, the FASB issued ASU 2018-13, "Fair Value Measurement (Topic 820)" ("ASU 2018-13"). ASU 2018-13 modifies the disclosure requirements on fair value measurements in Topic 820, Fair Value Measurement, based on the concepts in the Concepts Statement, including the consideration of costs and benefits. ASU 2018-13 is effective for fiscal years ending after December 15, 2019 and shall be applied to all periods presented on a retrospective basis. Early adoption is permitted. We are currently assessing and do not believe ASU 2018-13 will have a significant impact on our fair value measurements disclosure requirements. In August 2018, the FASB issued ASU 2018-14, "Compensation—Retirement Benefits—Defined Benefit Plans—General (Subtopic 715-20)" ("ASU 2018-14"). ASU 2018-14 eliminates requirements for certain disclosures and requires additional disclosures under defined benefit pension plans and other post-retirement plans. ASU 2018-14 is effective for fiscal years ending after December 15, 2020 and shall be applied to all periods presented on a retrospective basis. Early adoption is permitted. We are currently assessing and do not believe ASU 2018-14 will have a significant impact on our defined benefit plan disclosure requirements. Recently adopted accounting pronouncements In February 2018, the FASB issued ASU 2018-02, "Income Statement—Reporting Comprehensive Income" to give companies the option to reclassify the income tax effects on items within accumulated other comprehensive income resulting from the Tax Act to retained earnings. ASU 2018-02 is effective for fiscal years beginning after December 15, 2018, including interim periods within those years. We adopted ASU 2018-02 during the first quarter of fiscal year 2019 which did not materially impact on our Consolidated Financial Statements. In June 2018, the FASB issued ASU 2018-07, "Compensation-Stock Compensation (Topic 718)", Improvements to Non-employee Share-based Payments (“ASU 2018-07”). This ASU expands the scope of Topic 718 to include share-based payment transactions for acquiring goods and services from non-employees. ASU 2018-07 is effective for fiscal years beginning after December 15, 2018. The new guidance is required to be applied retrospectively with the cumulative effect recognized at the date of initial application. We adopted ASU 2018-07 during the first quarter of fiscal year 2019 which did not materially impact on our Consolidated Financial Statements. In August 2017, the FASB issued ASU 2017-12, "Derivatives and Hedging (Topic 815)", Targeted Improvements to Accounting for Hedging Activities ("ASU 2017-12"). This ASU simplifies certain aspects of hedge accounting and results in a more accurate portrayal of the economics of an entity’s risk management activities in its financial statements. ASU 2017-12 is effective for fiscal years beginning after December 15, 2018, and the interim periods within those fiscal years. We adopted ASU 2017-12 during the first quarter of fiscal year 2019 using the modified retrospective basis. The adoption of the provisions of ASU 2017-12 did not materially impact the Company’s Consolidated Balance Sheet or Statement of Operations. In February 2016, the FASB issued ASU 2016-02, "Leases (Topic 842)," to increase transparency and comparability among organizations by recognizing lease right-of-use assets and lease liabilities on the balance sheet and disclosing key information about leasing arrangements. ASU 2016-02 is effective for fiscal years beginning after December 15, 2018, including interim periods within the year of adoption. We adopted ASU 2016-02 using the modified retrospective approach and recorded $38.2 million of operating lease right-of-use assets and $38.4 million of operating lease liabilities as the cumulative-effect in the first quarter of fiscal year 2019. As of September 30, 2019, we have recorded $111.2 million of operating lease right-of-use assets and $112.7 million of operating lease liabilities. The adoption of ASU 2016-02 did not materially impact the Company’s Consolidated Statement of Operations or Consolidated Statement of Cash Flows for the period ended September 30, 2019.

Business Acquisitions

Business Acquisitions	9 Months Ended
	Sep. 30, 2019
Business Acquisitions
BUSINESS ACQUISITIONS	NOTE 2. BUSINESS ACQUISITIONS Artesyn’s Embedded Power Business In September 2019, we completed the acquisition of Artesyn Embedded Technologies, Inc.’s (“Artesyn”) Embedded Power business pursuant to the Stock Purchase Agreement (“Acquisition Agreement”), as amended, dated May 14, 2019. Pursuant to the Acquisition Agreement, we acquired all of Artesyn’s issued and outstanding shares for a purchase price of $367.8 million including the assumption of certain liabilities and subject to an adjustment for net working capital. In connection with the Acquisition Agreement, we entered into a credit agreement that provided us with aggregate financing of $500.0 million which was used to partially fund the Artesyn acquisition. Note 22. Credit Facility for additional details related to the credit agreement. Artesyn’s Embedded Power business is one of the world’s largest providers of highly engineered, application-specific power supplies for demanding applications. This acquisition will diversify our product portfolio and give us access to additional growth markets, including hyperscale data centers, telecom infrastructure in next generation 5G networks, embedded industrial power applications and medical power for diagnostic and treatment applications. The components of the fair value of the total consideration transferred for the acquisition is as follows: ​ ​ ​ ​ ​ ​ Artesyn Cash paid for acquisition ​ $ 389,023 Non-cash consideration ​ ​ 2,000 Total fair value of consideration transferred ​ ​ 391,023 Less cash acquired ​ (23,225) Total purchase price ​ $ 367,798 ​ ​ The following table summarizes the estimated preliminary fair values of the assets acquired and liabilities assumed from the acquisition: ​ ​ ​ ​ ​ ​ Preliminary: September 10, 2019 Accounts and other receivable, net ​ $ 128,221 Inventories ​ 140,678 Property and equipment ​ 65,016 Operating lease right-of-use assets ​ ​ 60,217 Goodwill ​ 143,262 Intangible assets ​ 125,000 Deferred income tax assets ​ 14,767 Other assets ​ 61,511 Total assets acquired ​ 738,672 Accounts payable ​ 144,652 Operating lease liability ​ ​ 59,634 Pension liability ​ ​ 48,494 Deferred income tax liabilities ​ 37,218 Other liabilities ​ 80,876 Total liabilities assumed ​ 370,874 Total fair value of net assets acquired ​ $ 367,798 ​ A summary of the intangible assets acquired, amortization method and estimated useful lives are as follows: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Amortization ​ ​ ​ Artesyn ​ Method ​ Useful Life Technology ​ $ 30,000 Straight-line 5 Customer relationships ​ 75,000 Straight-line 15 Tradename ​ 20,000 Straight-line 10 Total ​ $ 125,000 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Goodwill and intangible assets are recorded in the functional currency of the entity and are subject to changes due to translation at each balance sheet date. The goodwill represents expected operating synergies from combining operations with the acquired companies and the estimated value associated with the enhancements to our comprehensive product lines and access to new markets. Advanced Energy is still evaluating the fair value for the assets acquired and liabilities assumed related to the Artesyn acquisition. Accordingly, the purchase price allocation presented above is preliminary. ​ LumaSense Technologies Holdings, Inc. In September 2018, we acquired LumaSense Technologies Holdings, Inc. ("LumaSense"), a privately held company with primary operations in Santa Clara, California; Frankfurt, Germany; and Ballerup, Denmark for a net purchase price of $84.7 million in cash. LumaSense designs, manufactures and sells a line of photonic-based measurement and monitoring solutions that are synergistic with the Company's precision power control technologies in both semiconductor and industrial markets allowing customers the ability to better control critical parameters of thermal and material processes. The acquisition of LumaSense expands our current electrostatic chuck solutions, including high voltage power supply and electrostatic metrology, complements our leading pyrometry solutions with additional fiber optic thermometry for an extended range of semiconductor applications in etch and deposition, provides integrated industrial temperature control and metrology applications for both thin films coating and thermal processing, and adds industrial pyrometry and gas sensing technologies. The components of the fair value of the total consideration transferred for our acquisition is as follows: ​ ​ ​ ​ ​ ​ LumaSense Cash paid for acquisition ​ $ 94,946 Cash acquired ​ (10,262) Total fair value of consideration transferred ​ $ 84,684 ​ The following table summarizes the fair values of the assets acquired and liabilities assumed from our acquisition, including measurement period adjustments: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Preliminary: September 1, 2018 ​ Measurement Period Adjustments ​ Adjusted: September 1, 2018 Accounts and other receivable, net ​ $ 7,167 ​ $ - ​ $ 7,167 Inventories ​ 9,372 ​ ​ - ​ ​ 9,372 Property and equipment ​ 1,353 ​ ​ - ​ ​ 1,353 Goodwill ​ 48,032 ​ ​ (11,774) ​ ​ 36,258 Intangible assets ​ 26,000 ​ ​ 17,240 ​ ​ 43,240 Deferred income tax assets ​ 8,116 ​ ​ (1,785) ​ ​ 6,331 Other assets ​ 5,126 ​ ​ 878 ​ ​ 6,004 Total assets acquired ​ 105,166 ​ ​ 4,559 ​ ​ 109,725 Accounts payable ​ 5,734 ​ ​ - ​ ​ 5,734 Deferred income tax liabilities ​ 7,984 ​ ​ 3,715 ​ ​ 11,699 Other liabilities ​ 6,764 ​ ​ 844 ​ ​ 7,608 Total liabilities assumed ​ 20,482 ​ ​ 4,559 ​ ​ 25,041 Total fair value of net assets acquired ​ $ 84,684 ​ $ - ​ $ 84,684 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ A summary of the intangible assets acquired, amortization method and estimated useful lives are as follows: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Amortization ​ ​ ​ LumaSense ​ Method ​ Useful Life Technology ​ $ 35,530 Straight-line 15 Customer relationships ​ 4,360 Straight-line 10 Tradename ​ 3,350 Straight-line 10 Total ​ $ 43,240 ​ Goodwill and intangible assets are recorded in the functional currency of the entity and are subject to changes due to translation at each balance sheet date. The goodwill represents expected operating synergies from combining operations with the acquired companies and the estimated value associated with the enhancements to our comprehensive product lines. During the nine months ended September 30, 2019, we adjusted the estimated values of the assets acquired and liabilities assumed based upon the valuation report. These adjustments included additional liabilities, changes to deferred taxes and changes in the allocation of excess purchase price between goodwill and intangibles. Pro forma results for Advanced Energy Inc. giving effect to the LumaSense Technologies Holdings, Inc. and the Artesyn Embedded Power Business Transactions The following unaudited pro forma financial information presents the combined results of operations of Advanced Energy, LumaSense and Artesyn as if each of the acquisitions had been completed at the beginning of the fiscal year prior to their acquisition. The unaudited pro forma financial information is presented for informational purposes and is not indicative of the results of operations that would have been achieved if the acquisitions had taken place at the beginning of the year prior to the acquisition dates, nor are they indicative of future results. The unaudited pro forma financial information for the three and nine months ended September 30, 2019 includes Advanced Energy’s results, including the post-acquisition results of LumaSense, since September 1, 2018 and the post-acquisition results of Artesyn, since September 10, 2019. The unaudited pro forma financial information for the three and nine months ended September 30, 2018 combines Advanced Energy’s results with the pre-acquisition results of LumaSense and Artesyn for that period. The following tables present our unaudited pro forma results for the acquisitions of LumaSense and Artesyn: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Three Months Ended September 30, ​ ​ 2019 ​ 2018 ​ As Reported Pro Forma As Reported Pro Forma Total sales $ 175,127 $ 292,669 $ 173,082 $ 333,050 Net income attributable to Advanced Energy Industries, Inc. $ 7,621 $ 11,095 $ 34,779 $ 36,887 Earnings per share: ​ ​ ​ ​ Basic earnings per share ​ $ 0.20 ​ $ 0.29 ​ $ 0.89 ​ $ 0.95 Diluted earnings per share ​ $ 0.20 ​ $ 0.29 ​ $ 0.89 ​ $ 0.94 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Nine Months Ended September 30, ​ ​ 2019 ​ 2018 ​ ​ As Reported Pro Forma As Reported Pro Forma Total sales ​ $ 450,680 $ 863,190 $ 564,731 $ 1,037,113 Net income attributable to Advanced Energy Industries, Inc. ​ $ 54,677 $ 58,615 $ 127,619 $ 135,994 Earnings per share: ​ ​ ​ ​ ​ Basic earnings per share ​ $ 1.43 ​ $ 1.53 ​ $ 3.25 ​ $ 3.46 Diluted earnings per share ​ $ 1.42 ​ $ 1.52 ​ $ 3.23 ​ $ 3.44 ​ The unaudited pro forma results for all periods presented include adjustments made to account for certain costs and transactions that would have been incurred had the acquisitions been completed at the beginning of the year prior to the year of acquisition. These include adjustments to amortization charges for acquired intangible assets, interest and financing expenses, transaction costs, amortization of purchased gross profit and the alignment of various accounting policies. These adjustments are net of any applicable tax impact and were included to arrive at the pro forma results above. LumaSense’s operating results have been included in the Advanced Energy’s operating results for the periods subsequent to the completion of the acquisition on September 1, 2018. During the three months ended September 30, 2019, LumaSense contributed total sales of $12.0 million and net income of $1.0 million. During the nine months ended September 30, 2019, LumaSense contributed total sales of $35.8 million and net income of $3.6 million. ​ Artesyn’s operating results have been included in the Advanced Energy’s operating results for the periods subsequent to the completion of the acquisition on September 10, 2019. During the three and nine months ended September 30, 2019, Artesyn contributed total sales of $40.9 million and net income of $1.2 million, including interest and other expense associated with the financing of the transaction. Cost of goods sold includes $1.5 million of acquisition related costs during the three and nine months ended September 30, 2019. Selling, general and administrative expenses includes $6.4 million and $7.9 million of acquisition related costs during the three and nine months ended September 30, 2019, respectively.

Revenue

Revenue	9 Months Ended
	Sep. 30, 2019
Revenue
REVENUE	NOTE 3. REVENUE Revenue Recognition We recognize revenue when we have satisfied our performance obligations which typically occurs when control of the products or services has been transferred to our customers. The transaction price is based upon the standalone selling price. In most transactions, we have no obligations to our customers after the date products are shipped, other than pursuant to warranty obligations. Shipping and handling fees billed to customers, if any, are recognized as revenue. The related shipping and handling costs are recognized in cost of sales. Support services include warranty and non-warranty repair services, upgrades, and refurbishments on the products we sell. Repairs that are covered under our standard warranty do not generate revenue. Practical Expedients We expense incremental costs of obtaining contracts when the amortization period of the costs is less than 1 year. These costs are included in selling, general, and administrative expenses. Nature of goods and services Products Advanced Energy provides highly engineered, mission-critical, precision power conversion, measurement and control solutions to our global customers. We design, manufacture, sell and support precision power products that transform electrical power into various usable forms. Our power conversion products refine, modify and control the raw electrical power from a utility and convert it into power that is predictable, repeatable and customizable. Our products enable thin film manufacturing processes such as plasma enhanced chemical and physical deposition and etch for various semiconductor and industrial products, industrial thermal applications for material and chemical processes, and specialty power for critical industrial technology applications. We also supply thermal instrumentation products for advanced temperature measurement and control in these markets. As a result of the Artesyn acquisition we now sell precision power conversion products into the telecom and networking, data center, and additional medical and industrial markets. Our products are designed to enable new process technologies, improve productivity, and lower the cost of ownership for our customers. We also provide repair and maintenance services for all our products. We principally serve original equipment manufacturers ("OEM") and end customers in the semiconductor, flat panel display, high voltage, solar panel, telecom and networking, data center, medical, and other industrial capital equipment markets. Our advanced power products are used in diverse markets, applications, and processes including the manufacture of capital equipment for semiconductor device manufacturing, thin film applications for thin film renewables and architectural glass, and for other thin film applications including flat panel displays, and industrial coatings. Our embedded power products are used in a wide range of applications, including 5G, datacenter including hyperscale and other industrial and medical applications. Services Our services group offers warranty and after-market repair services in the regions in which we operate, providing us with preventive maintenance opportunities. Our customers continue to pursue low cost of ownership of their capital equipment and are increasingly sensitive to the costs of system downtime. They expect that suppliers offer comprehensive local repair service and customer support. To meet these market requirements, we maintain a worldwide support organization comprising of both direct and indirect activities, through partnership with local distributors, primarily in the United States ("U.S."), the People’s Republic of China ("PRC"), Japan, South Korea, Taiwan, Germany, Singapore and United Kingdom. As part of our ongoing service business, we satisfy our service obligations under preventative maintenance contracts and extended warranties which had previously been offered on our discontinued inverter products. Any up-front fees received for extended warranties or maintenance plans are deferred. Revenue under these arrangements is recognized ratably over the underlying terms as we do not have historical information which would allow us to project the estimated service usage pattern at this time. In May 2019, we sold our grid-tied central inverter repair and service operation to a third party. In connection with this sale, approximately $22.0 million of deferred revenue related to extended warranties and service contracts, were transferred to the buyer. See Note 4. Disposed and Discontinued Operations Disaggregation of Revenue The following table presents our net sales by market, inclusive of both products and services, which reflects a reclassification in prior periods to conform to the current presentation: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Three Months Ended September 30, ​ Nine Months Ended September 30, ​ ​ 2019 2018 2019 2018 ​ Semiconductor Equipment ​ $ 96,426 ​ $ 119,969 ​ $ 277,911 ​ $ 426,380 ​ Telecom & Networking ​ ​ 10,016 ​ ​ — ​ ​ 10,016 ​ ​ — ​ Data Center Computing ​ ​ 13,498 ​ ​ — ​ ​ 13,498 ​ ​ — ​ Industrial & Medical ​ 55,187 ​ 53,113 ​ 149,255 ​ 138,351 ​ Total ​ $ 175,127 ​ $ 173,082 ​ $ 450,680 ​ $ 564,731 ​ ​ The following table presents our net sales by geographic region, which includes a reclassification in prior periods to conform to the current presentation: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Three Months Ended September 30, ​ Nine Months Ended September 30, ​ 2019 ​ 2018 ​ 2019 ​ 2018 North America ​ $ 83,632 $ 85,728 ​ $ 203,531 $ 295,567 Asia ​ 66,157 ​ 61,691 ​ ​ 175,554 ​ 198,020 Europe ​ 25,008 ​ 25,538 ​ ​ 70,526 ​ 70,802 Other Countries ​ 330 ​ 125 ​ ​ 1,069 ​ 342 Total ​ $ 175,127 $ 173,082 ​ $ 450,680 $ 564,731 ​ The following table presents our net sales by extended warranty and service contracts recognized over time and our product and service revenue recognized at a point in time: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Three Months Ended September 30, ​ Nine Months Ended September 30, ​ ​ 2019 2018 2019 2018 ​ Product and service revenue recognized at point in time ​ $ 174,827 ​ $ 171,806 ​ $ 448,964 ​ $ 561,578 ​ Extended warranty and service contracts recognized over time ​ 300 ​ 1,276 ​ 1,716 ​ 3,153 ​ Total ​ $ 175,127 ​ $ 173,082 ​ $ 450,680 ​ $ 564,731 ​ ​

Disposed and Discontinued Opera

Disposed and Discontinued Operations	9 Months Ended
	Sep. 30, 2019
Disposed and Discontinued Operations
DISPOSED AND DISCONTINUED OPERATIONS	NOTE 4. DISPOSED AND DISCONTINUED OPERATIONS Disposed Operations In May 2019, we sold our grid-tied central solar inverter services business to Bold Renewables Holdings, LLC (“Buyer”) for $1.00 dollar and assumption of our initial product warranty and our extended warranty service obligations. In connection with this transaction, we entered into a Loan and Security Agreement with the Buyer. Under this agreement, we initially loaned $2.8 million to the buyer at closing and have made available an additional $5.25 million that may be borrowed in the future, subject to certain operating and liquidity covenants, for operating needs over the next ten years. The borrowings under the Loan and Security Agreement bear interest at 0% for the first seven years and 5% thereafter. Additionally, the Loan and Security Agreement provides for early payment discounts of 50% during the first three years, 45% for years four and five and 40% thereafter up to 30 days prior to the maturity of the Loan and Security Agreement. A discount on the initial $2.8 million funding under the Loan and Security Agreement of $2.3 million has been recognized as a reduction to the gain recognized on the sale. As a result of the transaction, we reduced our liabilities held in discontinued operations approximately $10.9 million related to initial product warranty and reduced Other liabilities of our continuing operations of approximately $22.0 million related to extended warranty service obligations as well as other assets and liabilities associated with the continuing grid-tied central solar inverter service and repair business. A $14.8 million non-cash gain was recognized in Other income (expense) from continuing operations and an $8.6 million non-cash gain, net of tax expense of $2.4 million, was recognized in Income from discontinued operations. Discontinued Operations In December 2015, we completed the wind down of engineering, manufacturing and sales of our solar inverter product line (the "inverter business"). Accordingly, the results of our inverter business have been reflected as "Income (loss) from discontinued operations, net of income taxes" on our Consolidated Statements of Operations for all periods presented herein. The effect of our sales of extended inverter warranties to our customers continues to be reflected in deferred revenue in our Consolidated Balance Sheets. Deferred revenue for extended inverter warranties and the associated costs of warranty service will be reflected in Sales and Cost of goods sold, respectively, from continuing operations in future periods in our Consolidated Statement of Operations, as the deferred revenue, is earned and the associated services are rendered. Extended warranties related to the inverter product line are no longer offered. The significant items included in "Income (loss) from discontinued operations, net of income taxes" are as follows: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Three Months Ended September 30, ​ Nine Months Ended September 30, ​ ​ 2019 2018 2019 2018 ​ Sales ​ $ — ​ $ — ​ $ — ​ $ — ​ Cost of sales ​ (700) ​ — ​ (900) ​ (88) ​ Total operating expense ​ 133 ​ — ​ 514 ​ 31 ​ Operating income from discontinued operations ​ 567 ​ — ​ 386 ​ 57 ​ Other income (expense) ​ (84) ​ (258) ​ 10,835 ​ (261) ​ Income (loss) from discontinued operations before income taxes ​ 483 ​ (258) ​ 11,221 ​ (204) ​ Provision (benefit) for income taxes ​ 108 ​ 113 ​ 2,531 ​ 22 ​ Income (loss) from discontinued operations, net of income taxes ​ $ 375 ​ $ (371) ​ $ 8,690 ​ $ (226) ​ ​ Assets and Liabilities of discontinued operations within the Condensed Consolidated Balance Sheets are comprised of the following: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ September 30, ​ December 31, ​ ​ 2019 2018 ​ Cash and cash equivalents ​ $ — ​ $ 5,251 ​ Other current assets ​ ​ — ​ ​ 406 ​ Inventories ​ ​ 84 ​ ​ 198 ​ Current assets of discontinued operations ​ $ 84 ​ $ 5,855 ​ ​ ​ ​ ​ ​ ​ ​ ​ Other assets ​ $ — ​ $ 67 ​ Deferred income tax assets ​ 755 ​ 5,917 ​ Non-current assets of discontinued operations ​ $ 755 ​ $ 5,984 ​ ​ ​ ​ ​ ​ ​ ​ ​ Accounts payable and other accrued expenses ​ $ — ​ $ 350 ​ Accrued warranty ​ 910 ​ 4,936 ​ Current liabilities of discontinued operations ​ $ 910 ​ $ 5,286 ​ ​ ​ ​ ​ ​ ​ ​ ​ Accrued warranty ​ $ 903 ​ $ 10,429 ​ Other liabilities ​ 142 ​ 286 ​ Non-current liabilities of discontinued operations ​ $ 1,045 ​ $ 10,715 ​ ​

Income Taxes

Income Taxes	9 Months Ended
	Sep. 30, 2019
Income Taxes
INCOME TAXES	NOTE 5. INCOME TAXES The following table sets out the tax expense and the effective tax rate for our income from continuing operations: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Three Months Ended September 30, ​ Nine Months Ended September 30, ​ ​ 2019 2018 2019 2018 ​ Income from continuing operations, before income taxes ​ $ 10,751 ​ $ 40,263 ​ $ 49,835 ​ $ 151,925 ​ Provision for income taxes ​ ​ 3,495 ​ ​ 5,106 ​ ​ 3,819 ​ ​ 23,998 ​ Effective tax rate ​ ​ 32.5 % ​ 12.7 % ​ 7.7 % ​ 15.8 % ​ Our effective tax rates differ from the U.S. federal statutory rate of 21% for the three and nine months ended September 30, 2019 and 2018, respectively, primarily due to the benefit of earnings in foreign jurisdictions which are subject to lower tax rates, partially offset by additional GILTI tax in the U.S. The effective tax rate for the first nine months of 2019 was lower than the same period in 2018 primarily due to the release of liabilities for uncertain tax positions in the first quarter of 2019 based on the completion of additional procedures during the quarter to support a change in facts with respect to a specific prior period position. The higher effective tax rate in the three months ended September 2019 was primarily due to the non-deductibility of certain transaction costs related to the Artesyn transaction and a change in the indefinite reinvestment assertion of unremitted earnings in China and Korea.

Earnings Per Share

Earnings Per Share	9 Months Ended
	Sep. 30, 2019
Earnings Per Share
EARNINGS PER SHARE	NOTE 6. EARNINGS PER SHARE Basic earnings per share ("EPS") is computed by dividing income available to common stockholders by the weighted-average number of common shares outstanding during the period. The computation of our diluted EPS is similar to the computation of our basic EPS except that the denominator is increased to include the number of additional common shares that would have been outstanding (using the if-converted and treasury stock methods), if our outstanding stock options and restricted stock units had been converted to common shares, and if such assumed conversion is dilutive. The following is a reconciliation of the weighted-average shares outstanding used in the calculation of basic and diluted EPS for the three and nine months ended September 30, 2019 and 2018: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Three Months Ended September 30, ​ Nine Months Ended September 30, ​ ​ 2019 2018 2019 2018 ​ Income from continuing operations ​ $ 7,256 ​ $ 35,157 ​ $ 46,016 ​ $ 127,927 ​ Income from continuing operations attributable to noncontrolling interest ​ 10 ​ 7 ​ 29 ​ 82 ​ Income from continuing operations attributable to Advanced Energy Industries, Inc. ​ $ 7,246 ​ $ 35,150 ​ $ 45,987 ​ $ 127,845 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Basic weighted-average common shares outstanding ​ 38,313 ​ 38,970 ​ 38,258 ​ 39,309 ​ Assumed exercise of dilutive stock options and restricted stock units ​ 176 ​ 225 ​ 199 ​ 285 ​ Diluted weighted-average common shares outstanding ​ 38,489 ​ 39,195 ​ 38,457 ​ 39,594 ​ Continuing operations: ​ ​ ​ ​ ​ Basic earnings per share ​ $ 0.19 ​ $ 0.90 ​ $ 1.20 ​ $ 3.25 ​ Diluted earnings per share ​ $ 0.19 ​ $ 0.90 ​ $ 1.20 ​ $ 3.23 ​ ​ The following restricted stock units were excluded in the computation of diluted earnings per share because they were anti-dilutive: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Three Months Ended September 30, ​ Nine Months Ended September 30, ​ ​ 2019 2018 2019 2018 ​ Restricted stock units 4 1 1 — ​ Stock Buyback In September 2015, our Board of Directors authorized a program to repurchase up to $150.0 million of our stock over a thirty-month period. In November 2017, our Board of Directors approved an extension of the share repurchase program to December 2019 from its original maturity of March 2018. In May 2018 our Board of Directors approved a $50 million increase in its authorization to repurchase shares of Company common stock under this same program. As of September 30, 2019, we had $24.9 million remaining for the future repurchase of shares of our common stock. In order to execute the repurchase of shares of our common stock, the company periodically enters into stock repurchase agreements. During the three and nine months ended September 30, 2019 and 2018, the company has repurchased the following shares of common stock: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Three Months Ended September 30, ​ Nine Months Ended September 30, ​ ​ 2019 2018 2019 2018 ​ Amount paid to repurchase shares ​ $ — ​ $ 30,962 ​ $ — ​ $ 69,021 ​ Number of shares repurchased ​ — ​ 533 ​ — ​ 1,121 ​ Average repurchase price per share ​ $ — ​ $ 58.12 ​ $ — ​ $ 61.57 ​ ​ There were no shares repurchased from related parties. All shares repurchased were recognized as a reduction to Additional paid-in capital. Repurchased shares were retired and assumed the status of authorized and unissued shares.

Marketable Securities and Asset

Marketable Securities and Assets Measured at Fair Value	9 Months Ended
	Sep. 30, 2019
Marketable Securities and Assets Measured at Fair Value
MARKETABLE SECURITIES AND ASSETS MEASURED AT FAIR VALUE	NOTE 7. MARKETABLE SECURITIES AND ASSETS MEASURED AT FAIR VALUE Our investments with original maturities of more than three months at the time of purchase and that are intended to be held for no more than 12 months, are considered marketable securities available for sale. Our marketable securities consist of certificates of deposit as follows: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ September 30, 2019 ​ December 31, 2018 ​ Cost Fair Value Cost Fair Value Total marketable securities ​ $ 741 ​ $ 747 ​ $ 2,463 ​ $ 2,470 ​ The maturities of our marketable securities available for sale as of September 30, 2019 are as follows: ​ ​ ​ ​ ​ ​ ​ ​ ​ Earliest ​ Latest Certificates of deposit 10/14/2019 to 7/28/2020 ​ The value and liquidity of the marketable securities we hold are affected by market conditions, as well as the ability of the issuers of such securities to make principal and interest payments when due, and the functioning of the markets in which these securities are traded. As of September 30, 2019, we do not believe any of the underlying issuers of our marketable securities are at risk of default. The following tables present information about our marketable securities measured at fair value, on a recurring basis, as of September 30, 2019 and December 31, 2018. The tables indicate the fair value hierarchy of the valuation techniques utilized to determine fair value. We did not have any financial liabilities measured at fair value, on a recurring basis, as of September 30, 2019 and December 31, 2018. ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ September 30, 2019 Level 1 Level 2 Level 3 Total Total marketable securities ​ $ — ​ $ 747 ​ $ — ​ $ 747 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, 2018 Level 1 Level 2 Level 3 Total Total marketable securities ​ $ — ​ $ 2,470 ​ $ — ​ $ 2,470 ​ There were no transfers in or out of Level 1, 2, or 3 fair value measurements during three and nine months ended September 30, 2019.

Derivative Financial Instrument

Derivative Financial Instruments	9 Months Ended
	Sep. 30, 2019
Derivative Financial Instruments
DERIVATIVE FINANCIAL INSTRUMENTS	NOTE 8. DERIVATIVE FINANCIAL INSTRUMENTS We are impacted by changes in foreign currency exchange rates. We may manage these risks through the use of derivative financial instruments, primarily forward contracts with banks for one-month periods. These forward contracts manage the exchange rate risk associated with intercompany debt denominated in nonfunctional currencies. These derivative instruments are not designated as hedges; however, they do offset the fluctuations of our intercompany debt due to foreign exchange rate changes. We did not enter into any new foreign currency exchange forward contracts during the three and nine months ended September 30, 2019 and 2018. We did not have any currency exchange rate contracts outstanding as of September 30, 2019 and 2018. During the three and nine months ended September 30, 2019 and 2018 the gains and losses recorded related to the foreign currency exchange contracts are as follows: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Three Months Ended September 30, ​ Nine Months Ended September 30, ​ ​ 2019 2018 2019 2018 ​ Foreign currency loss from foreign currency exchange contracts ​ $ — ​ $ — ​ $ — ​ $ (750) ​ ​ These gains and losses were offset by corresponding gains and losses on the revaluation of the underlying intercompany debt and both are included as a component of Other income (expense), net, in our Unaudited Condensed Consolidated Statements of Operations.

Accounts and Other Receivable

Accounts and Other Receivable	9 Months Ended
	Sep. 30, 2019
Accounts and Other Receivable
ACCOUNTS AND OTHER RECEIVABLE	NOTE 9. ACCOUNTS AND OTHER RECEIVABLE Accounts and other receivable are recorded at net realizable value. Components of accounts and other receivable, net of reserves, are as follows: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ September 30, ​ December 31, ​ 2019 2018 Amounts billed, net ​ $ 233,464 ​ $ 80,709 Unbilled receivables ​ ​ 16,687 ​ 19,733 Total receivables, net ​ $ 250,151 ​ $ 100,442 ​ Amounts billed, net consist of amounts that have been invoiced to our customers in accordance with our terms and conditions and are shown net of an allowance for doubtful accounts. Unbilled receivables consist of amounts where we have satisfied our contractual obligations related to inventory stocking contracts with customers. Such amounts typically become billable to the customer upon their consumption of the inventory managed under the stocking contracts. We anticipate that substantially all unbilled receivables will be invoiced and collected over the next twelve months.

Inventories

Inventories	9 Months Ended
	Sep. 30, 2019
Inventories
INVENTORIES	NOTE 10. INVENTORIES Our inventories are valued at the lower of cost or net realizable value and computed on a first-in, first-out (FIFO) basis. Components of inventories are as follows: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ September 30, ​ December 31, ​ ​ 2019 2018 ​ Parts and raw materials ​ $ 141,672 ​ $ 76,647 ​ Work in process ​ 13,810 ​ 6,644 ​ Finished goods ​ 85,217 ​ 14,696 ​ Total ​ $ 240,699 ​ $ 97,987 ​ ​

Property and Equipment

Property and Equipment	9 Months Ended
	Sep. 30, 2019
Property and Equipment
PROPERTY AND EQUIPMENT	NOTE 11. PROPERTY AND EQUIPMENT Property and equipment, net is comprised of the following: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ September 30, ​ December 31, ​ ​ 2019 2018 ​ Buildings and land ​ $ 1,633 ​ $ 1,737 ​ Machinery and equipment ​ 93,657 ​ 41,330 ​ Computer and communication equipment ​ 31,204 ​ 24,051 ​ Furniture and fixtures ​ 4,574 ​ 3,203 ​ Vehicles ​ 1,154 ​ 282 ​ Leasehold improvements ​ 33,666 ​ 20,593 ​ Construction in process ​ 6,777 ​ 867 ​ ​ ​ 172,665 ​ 92,063 ​ Less: Accumulated depreciation ​ (68,097) ​ (60,794) ​ Property and equipment, net ​ $ 104,568 ​ $ 31,269 ​ ​ Depreciation expense recorded in continuing operations and included in selling, general and administrative expense is as follows: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Three Months Ended September 30, ​ Nine Months Ended September 30, ​ ​ 2019 2018 2019 2018 ​ Depreciation expense ​ $ 3,903 ​ $ 2,134 ​ $ 8,452 ​ $ 5,530 ​ ​

Goodwill

Goodwill	9 Months Ended
	Sep. 30, 2019
Goodwill and Intangible Assets
GOODWILL	NOTE 12. GOODWILL The following summarizes the changes in goodwill during the nine months ended September 30, 2019: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Effect of ​ ​ ​ Beginning ​ ​ ​ ​ ​ Changes in Ending ​ ​ Balance ​ Adjustments Additions Exchange Rates ​ Balance September 30, 2019 ​ $ 101,900 ​ $ (11,774) ​ $ 143,262 ​ $ (1,188) ​ $ 232,200 ​

Intangible Assets

Intangible Assets	9 Months Ended
	Sep. 30, 2019
Goodwill and Intangible Assets
INTANGIBLE ASSETS	NOTE 13. INTANGIBLE ASSETS Intangible assets consisted of the following as of September 30, 2019 and December 31, 2018: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Gross Carrying Accumulated Net Carrying September 30, 2019 ​ Amount ​ Amortization ​ Amount Technology ​ $ 84,814 ​ $ (11,337) ​ $ 73,477 Customer relationships ​ 108,176 ​ (15,745) ​ 92,431 Trademarks and other ​ 25,766 ​ (2,073) ​ 23,693 Total ​ $ 218,756 ​ $ (29,155) ​ $ 189,601 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Gross Carrying Accumulated Net Carrying December 31, 2018 ​ Amount ​ Amortization ​ Amount Technology ​ $ 39,879 ​ $ (7,927) ​ $ 31,952 Customer relationships ​ 35,509 ​ (13,484) ​ 22,025 Trademarks and other ​ 2,501 ​ (1,568) ​ 933 Total ​ $ 77,889 ​ $ (22,979) ​ $ 54,910 ​ Amortization expense related to intangible assets is as follows: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Three Months Ended September 30, ​ Nine Months Ended September 30, ​ ​ 2019 2018 2019 2018 ​ Amortization expense ​ $ 3,002 ​ $ 1,437 ​ $ 6,849 ​ $ 3,958 ​ ​ Estimated amortization expense related to intangibles is as follows: ​ ​ ​ ​ ​ Year Ending December 31, ​ ​ 2019 (remaining) ​ $ 5,555 2020 ​ 20,307 2021 ​ 20,209 2022 ​ 19,953 2023 ​ 19,935 Thereafter ​ 103,642 Total ​ $ 189,601 ​

Restructuring Costs

Restructuring Costs	9 Months Ended
	Sep. 30, 2019
Restructuring Costs
RESTRUCTURING COSTS	NOTE 14. RESTRUCTURING COSTS During 2018, we committed to a restructuring plan to optimize our manufacturing footprint and to improve our operating efficiencies and synergies related to our recent acquisitions. The table below summarizes the restructuring charges: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Three Months ​ Nine Months ​ Cumulative Cost ​ ​ ​ Ended September 30, ​ Ended September 30, ​ Through September 30, ​ ​ ​ 2019 ​ 2019 ​ 2019 ​ Severance and related charges $ 150 $ 1,868 $ 6,107 Facility relocation and closure charges ​ 2 ​ 1,752 ​ 1,752 Total restructuring charges $ 152 $ 3,620 $ 7,859 ​ ​ The following table summarizes our restructuring liabilities at September 30, 2019: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Cost ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Incurred ​ Cost Paid ​ Effect of ​ ​ ​ ​ ​ Balance at ​ and ​ or ​ Changes in ​ Balance at ​ ​ December 31, ​ Charged to ​ Otherwise ​ Exchange ​ September 30, ​ ​ 2018 ​ Expense ​ Settled ​ Rates ​ 2019 Total restructuring liabilities ​ $ 3,806 ​ $ 3,620 ​ $ (5,560) ​ $ 1 ​ $ 1,867 ​ As of December 31, 2018, and September 30, 2019 the accrued restructuring liabilities related primarily to severance and related charges.

Warranties

Warranties	9 Months Ended
	Sep. 30, 2019
Warranties
WARRANTIES	NOTE 15. WARRANTIES Provisions of our sales agreements include customary product warranties, ranging from 12 months to 24 months following installation. The estimated cost of our warranty obligation is recorded when revenue is recognized and is based upon our historical experience by product and configuration. Our estimated warranty obligation is included in Other accrued expenses in our Consolidated Balance Sheets. Changes in our product warranty obligation are as follows: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Three Months Ended September 30, ​ Nine Months Ended September 30, ​ ​ 2019 2018 2019 2018 ​ Balances at beginning of period ​ $ 3,263 ​ $ 1,981 ​ $ 2,084 ​ $ 2,312 ​ Acquired warranty ​ 3,618 ​ 213 ​ 4,818 ​ 305 ​ Increases to accruals ​ 286 ​ 436 ​ 890 ​ 920 ​ Warranty expenditures ​ (414) ​ (590) ​ (1,045) ​ (1,492) ​ Effect of changes in exchange rates ​ (11) ​ (2) ​ (5) ​ (7) ​ Balances at end of period ​ $ 6,742 ​ $ 2,038 ​ $ 6,742 ​ $ 2,038 ​ ​

Leases

Leases	9 Months Ended
	Sep. 30, 2019
Leases
LEASES	NOTE 16. LEASES We lease manufacturing and office space under non-cancelable operating leases. Some of these leases contain provisions for landlord funded leasehold improvements which are recorded as right of use assets with related liabilities. Additionally, several existing operating leases had deferred rent balances under ASC 840 which resulted in adjusted right of use asset balances recorded upon adoption of ASC 842. Most leases include one or more options to renew. We regularly evaluate the renewal options and when they are reasonably certain of exercise, we include the renewal period in our lease terms, along with the right-of-use assets ("ROU") and lease liabilities. In many cases, we have lease terms that are less than one year and therefore, we have elected the practical expedient to exclude these short-term leases from our ROU assets and lease liabilities. New leases are negotiated and executed to meet business objectives on an on-going basis. Our leases do not provide an implicit rate. Accordingly, we use our incremental borrowing rate based on the information available at the lease commencement date in determining the present value of the lease payments. We have a centrally managed treasury function; therefore, based on the applicable lease terms and the current economic environment, we apply a portfolio approach for determining the incremental borrowing rate. ​ Maturities of our lease liabilities for all operating leases at September 30, 2019 are as follows: ​ ​ ​ ​ ​ Year Ending December 31, ​ 2019 (remaining) ​ $ 4,626 2020 ​ 20,196 2021 ​ 18,527 2022 ​ 13,713 2023 ​ 11,080 Thereafter ​ 71,003 Total lease payments ​ $ 139,145 Less: Interest ​ (26,396) Present value of lease liabilities ​ $ 112,749 ​ The weighted average remaining lease term and discount rate for all our operating leases as of September 30, 2019 were as follows: ​ ​ ​ ​ ​ ​ ​ ​ Weighted Average ​ ​ ​ Remaining Lease ​ Weighted Average ​ ​ Term ​ Discount Rate Operating leases 8.7 4.03 % ​ Cash paid for amounts included in the measurement of lease liabilities for the nine months ended September 30, 2019 was as follows: ​ ​ ​ ​ ​ ​ Cash Outflow Operating leases ​ $ 8,850 ​

Pension Liability

Pension Liability	9 Months Ended
	Sep. 30, 2019
Pension Liability
PENSION LIABILITY	NOTE 17. PENSION LIABILITY In connection with the acquisitions of HiTek Power Group, LumaSense and Artesyn we assumed the liabilities of various pension plans. In order to measure the expense and related benefit obligation, various assumptions are made including discount rates used to value the obligation, expected return on plan assets used to fund these expenses and estimated future inflation rates. These assumptions are based on historical experience as well as facts and circumstances. An actuarial analysis is used to measure the expense and liability associated with pension benefits. We are committed to make annual fixed payments of $0.8 million into the HiTek Power Limited Pension Scheme through April 30, 2024, and then $1.7 million from May 1, 2024 through November 30, 2033. We are obligated to fund the other pension liabilities each year as incurred. The net pension liability is included in Other long-term liabilities in our Consolidated Balance Sheets as follows: ​ ​ ​ ​ ​ ​ ​ ​ ​ September 30, December 31, ​ ​ 2019 ​ 2018 Pension liability ​ $ 66,450 ​ $ 19,266 ​ ​ The following table sets forth the components of net periodic pension cost for the three and nine months ended September 30, 2019 and 2018: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Three Months Ended September 30, ​ Nine Months Ended September 30, ​ ​ 2019 2018 2019 2018 ​ Service cost ​ $ 124 ​ $ — ​ $ 124 ​ $ — ​ Interest cost ​ ​ 274 ​ ​ 205 ​ ​ 668 ​ ​ 637 ​ Expected return on plan assets ​ (160) ​ ​ (151) ​ ​ (496) ​ ​ (470) ​ Amortization of actuarial gains and losses ​ 90 ​ ​ 64 ​ ​ 323 ​ ​ 333 ​ Net periodic pension cost ​ $ 328 ​ $ 118 ​ $ 619 ​ $ 500 ​ ​

Stock-Based Compensation

Stock-Based Compensation	9 Months Ended
	Sep. 30, 2019
Stock-Based Compensation
STOCK-BASED COMPENSATION	NOTE 18. STOCK-BASED COMPENSATION On May 4, 2017, the shareholders approved the Company’s 2017 Omnibus Incentive Plan ("the 2017 Plan") and all shares that were then available for issuance under the 2008 Omnibus Incentive Plan are now available for issuance under the 2017 Plan. The 2017 Plan provides for the grant of stock options, stock appreciation rights, restricted stock, stock units (including deferred stock units), unrestricted stock, and dividend equivalent rights. Any of the awards issued under the 2017 Plan may be issued as performance-based awards to align compensation awards to the attainment of annual or long-term performance goals. As of September 30, 2019, there were 3.0 million shares reserved and 2.3 million shares available for grant under the 2017 Plan. Restricted stock units ("RSU’s") are generally granted with a grant date fair value equal to the market price of our stock at the date of grant and with generally a three or four-year vesting schedule or performance-based vesting as determined at the time of grant. Stock option awards are generally granted with an exercise price equal to the market price of our stock at the date of grant and with either a three or four-year vesting schedule or performance-based vesting as determined at the time of grant. Stock option awards generally have a term of 10 years. We recognize stock-based compensation expense based on the fair value of the awards issued and the functional area of the employee receiving the award. Stock-based compensation for the three and nine months ended September 30, 2019 and 2018 was as follows: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Three Months Ended September 30, ​ Nine Months Ended September 30, ​ ​ 2019 2018 2019 2018 ​ Stock-based compensation expense ​ $ 917 ​ $ 1,024 ​ $ 5,053 ​ $ 7,461 ​ ​ Changes in the outstanding RSU awards during the three and nine months ended September 30, 2019 were as follows: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Three Months Ended September 30, 2019 ​ Nine Months Ended September 30, 2019 ​ ​ ​ Weighted- ​ Weighted- ​ ​ ​ ​ ​ Average ​ ​ ​ Average ​ ​ ​ ​ ​ Grant Date ​ ​ ​ Grant Date ​ ​ ​ Number of RSUs ​ Fair Value ​ Number of RSUs ​ Fair Value ​ RSUs outstanding at beginning of period 553 ​ $ 56.23 352 ​ $ 58.17 RSUs granted 18 ​ $ 57.01 377 ​ $ 52.18 RSUs vested (7) ​ $ 27.69 (153) ​ $ 50.90 RSUs forfeited (30) ​ $ 58.27 (42) ​ $ 51.74 RSUs outstanding at end of period 534 ​ $ 56.52 534 ​ $ 56.52 ​ Changes in the outstanding stock option awards during the three and nine months ended September 30, 2019 were as follows: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Three Months Ended September 30, 2019 ​ Nine Months Ended September 30, 2019 ​ ​ ​ Weighted- ​ Weighted- ​ ​ ​ ​ ​ Average ​ ​ ​ Average ​ ​ ​ Number of ​ Exercise Price ​ Number of ​ Exercise Price ​ ​ ​ Options ​ per Share ​ Options ​ per Share ​ Options outstanding at beginning of period 213 ​ $ 21.50 230 ​ $ 20.73 Options exercised (21) ​ $ 22.90 (37) ​ $ 18.03 Options expired (1) ​ $ 11.21 (2) ​ $ 8.95 Options outstanding at end of period 191 ​ $ 21.37 191 ​ $ 21.37 ​

Commitments and Contingencies

Commitments and Contingencies	9 Months Ended
	Sep. 30, 2019
Commitments and Contingencies
COMMITMENTS AND CONTINGENCIES	NOTE 19. COMMITMENTS AND CONTINGENCIES We have firm purchase commitments and agreements with various suppliers to ensure the availability of components. Purchase commitments as of September 30, 2019 are approximately $179.7 million. Our policy with respect to all purchase commitments is to record losses, if any, when they are probable and reasonably estimable. We continuously monitor these commitments for exposure to potential losses and will record a provision for losses when it is deemed necessary. We are involved in disputes and legal actions arising in the normal course of our business. There have been no material developments in legal proceedings in which we are involved during the three and nine months ended September 30, 2019. We are experiencing increasing claims from customers and suppliers and increasing litigation related to the legacy inverter product line.

Related Party Transactions

Related Party Transactions	9 Months Ended
	Sep. 30, 2019
Related Party Transactions
RELATED PARTY TRANSACTIONS	NOTE 20. RELATED PARTY TRANSACTIONS Members of our Board of Directors hold various executive positions and serve as directors at other companies, including companies that are our customers. During the three and nine months ended September 30, 2019 and 2018, we engaged in the following transactions with companies related to members of our Board of Directors, as described below: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Three Months Ended September 30, ​ Nine Months Ended September 30, ​ ​ 2019 2018 2019 2018 ​ Sales to related parties ​ $ 287 ​ $ — ​ $ 1,299 ​ $ 389 ​ Number of related party customers ​ 1 ​ — ​ 1 ​ 1 ​ Our accounts receivable balance from related party customers with outstanding balances as of September 30, 2019 and December 31, 2018 is as follows: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ September 30, ​ December 31, ​ 2019 2018 Accounts receivable from related parties ​ $ 41 ​ $ 109 Number of related party customers ​ 1 ​ 1 ​

Significant Customer Informatio

Significant Customer Information	9 Months Ended
	Sep. 30, 2019
Significant Customer Information
SIGNIFICANT CUSTOMER INFORMATION	​ ​ NOTE 21. SIGNIFICANT CUSTOMER INFORMATION The following table summarizes sales, and percentages of sales, by customers that individually accounted for 10% or more of our sales for the three and nine months ended September 30, 2019 and 2018: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Three Months Ended September 30, ​ 2019 ​ 2018 Applied Materials, Inc. ​ $ 38,957 22.2 % ​ $ 60,546 35.0 % LAM Research ​ 21,991 12.6 % ​ 19,878 11.5 % ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Nine Months Ended September 30, ​ 2019 ​ 2018 Applied Materials, Inc. ​ $ 108,978 24.2 % ​ $ 198,159 35.1 % LAM Research ​ 61,364 13.6 % ​ 92,368 16.4 % ​ The following table summarizes the accounts receivable balances, and percentages of the total accounts receivable, for customers that individually accounted for 10% or more of accounts receivable as of September 30, 2019 and December 31, 2018: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ September 30, December 31, ​ ​ 2019 ​ 2018 Applied Materials, Inc. ​ $ 30,669 12.3 % $ 34,301 34.2 % LAM Research ​ * * % 12,181 12.1 % ​ * Customer’s balance was less than 10% of the total accounts receivable balance.

Credit Facility

Credit Facility	9 Months Ended
	Sep. 30, 2019
Credit Facility
CREDIT FACILITY	NOTE 22. CREDIT FACILITY In September 2019, in connection with the Artesyn Acquisition Agreement, the Company entered into a credit agreement (“Credit Agreement”) that provided aggregate financing of $500.0 million, consisting of a $350.0 million senior unsecured term loan facility (the “Term Loan Facility”) and a $150.0 million senior unsecured revolving facility the (“Revolving Facility”). Both the Term Loan Facility and Revolving Facility mature on September 10, 2024. The Revolving Facility and Term Loan Facility bear interest, at the option of the Company, at a rate based on a reserve adjusted Eurodollar Rate or a Base Rate, as defined in the Credit Agreement, plus an applicable margin. Additionally, the Revolving Facility is subject to an unused line fee. As of September 30, 2019, the effective interest rate for the Revolving Facility and Term Loan Facility was 2.79% and the effective rate for the unused line fee was 0.10%. As of September 30, 2019, the Company had $150.0 million available to withdraw on the Revolving Facility and was in compliance with all covenants. In connection ​ ​ The debt obligation on our Condensed Consolidated Balance Sheets consists of the following: ​ ​ ​ ​ ​ ​ ​ ​ ​ September 30, ​ December 31, ​ 2019 2018 Debt: ​ ​ ​ ​ ​ ​ Term Loan Facility ​ $ 345,625 ​ $ — Revolving Facility ​ ​ — ​ ​ — Other debt issuance costs ​ ​ (2,356) ​ ​ — Total debt ​ ​ 343,269 ​ ​ — Less current portion of debt ​ ​ (17,500) ​ ​ — Total long-term debt ​ $ 325,769 ​ $ — ​ Contractual maturities of the Company’s debt obligations, excluding amortization of debt issuance costs, as of are as September 30, 2019 follows: ​ ​ ​ ​ ​ Amount 2019 (remaining) ​ $ 4,375 2020 ​ ​ 17,500 2021 ​ ​ 17,500 2022 ​ ​ 17,500 2023 ​ ​ 17,500 2024 ​ ​ 271,250 ​ Interest expense and unused line of credit fees were recorded in Other income (expense), net, in our Consolidated Statements of Operations as follows: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Three Months Ended September 30, ​ Nine Months Ended September 30, ​ ​ 2019 2018 2019 2018 ​ Interest expense ​ $ 703 ​ $ — ​ $ 703 ​ $ — ​ Amortization of debt issuance costs ​ ​ 45 ​ ​ — ​ ​ 45 ​ ​ — ​ Unused line of credit fees and other ​ ​ 60 ​ ​ 57 ​ ​ 179 ​ ​ 171 ​ Total interest expense ​ $ 808 ​ $ 57 ​ $ 927 ​ $ 171 ​ ​

Revenue (Policies)

Revenue (Policies)	9 Months Ended
	Sep. 30, 2019
Revenue
Revenue Recognition	We recognize revenue when we have satisfied our performance obligations which typically occurs when control of the products or services has been transferred to our customers. The transaction price is based upon the standalone selling price. In most transactions, we have no obligations to our customers after the date products are shipped, other than pursuant to warranty obligations. Shipping and handling fees billed to customers, if any, are recognized as revenue. The related shipping and handling costs are recognized in cost of sales. Support services include warranty and non-warranty repair services, upgrades, and refurbishments on the products we sell. Repairs that are covered under our standard warranty do not generate revenue.

Commitments and Contingencies (

Commitments and Contingencies (Policies)	9 Months Ended
	Sep. 30, 2019
Commitments and Contingencies
Purchase Commitments	Our policy with respect to all purchase commitments is to record losses, if any, when they are probable and reasonably estimable.

Business Acquisitions (Tables)

Business Acquisitions (Tables)	9 Months Ended
	Sep. 30, 2019
Business Acquisition [Line Items]
Schedule of unaudited pro forma information	The following tables present our unaudited pro forma results for the acquisitions of LumaSense and Artesyn: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Three Months Ended September 30, ​ ​ 2019 ​ 2018 ​ As Reported Pro Forma As Reported Pro Forma Total sales $ 175,127 $ 292,669 $ 173,082 $ 333,050 Net income attributable to Advanced Energy Industries, Inc. $ 7,621 $ 11,095 $ 34,779 $ 36,887 Earnings per share: ​ ​ ​ ​ Basic earnings per share ​ $ 0.20 ​ $ 0.29 ​ $ 0.89 ​ $ 0.95 Diluted earnings per share ​ $ 0.20 ​ $ 0.29 ​ $ 0.89 ​ $ 0.94 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Nine Months Ended September 30, ​ ​ 2019 ​ 2018 ​ ​ As Reported Pro Forma As Reported Pro Forma Total sales ​ $ 450,680 $ 863,190 $ 564,731 $ 1,037,113 Net income attributable to Advanced Energy Industries, Inc. ​ $ 54,677 $ 58,615 $ 127,619 $ 135,994 Earnings per share: ​ ​ ​ ​ ​ Basic earnings per share ​ $ 1.43 ​ $ 1.53 ​ $ 3.25 ​ $ 3.46 Diluted earnings per share ​ $ 1.42 ​ $ 1.52 ​ $ 3.23 ​ $ 3.44
Artesyn's Embedded Power Business [Member]
Business Acquisition [Line Items]
Schedule of components of the fair value of total consideration transferred	The components of the fair value of the total consideration transferred for the acquisition is as follows: ​ ​ ​ ​ ​ ​ Artesyn Cash paid for acquisition ​ $ 389,023 Non-cash consideration ​ ​ 2,000 Total fair value of consideration transferred ​ ​ 391,023 Less cash acquired ​ (23,225) Total purchase price ​ $ 367,798
Schedule of estimated fair value of assets acquired and liabilities assumed	​ The following table summarizes the estimated preliminary fair values of the assets acquired and liabilities assumed from the acquisition: ​ ​ ​ ​ ​ ​ Preliminary: September 10, 2019 Accounts and other receivable, net ​ $ 128,221 Inventories ​ 140,678 Property and equipment ​ 65,016 Operating lease right-of-use assets ​ ​ 60,217 Goodwill ​ 143,262 Intangible assets ​ 125,000 Deferred income tax assets ​ 14,767 Other assets ​ 61,511 Total assets acquired ​ 738,672 Accounts payable ​ 144,652 Operating lease liability ​ ​ 59,634 Pension liability ​ ​ 48,494 Deferred income tax liabilities ​ 37,218 Other liabilities ​ 80,876 Total liabilities assumed ​ 370,874 Total fair value of net assets acquired ​ $ 367,798
Summary of intangible assets	A summary of the intangible assets acquired, amortization method and estimated useful lives are as follows: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Amortization ​ ​ ​ Artesyn ​ Method ​ Useful Life Technology ​ $ 30,000 Straight-line 5 Customer relationships ​ 75,000 Straight-line 15 Tradename ​ 20,000 Straight-line 10 Total ​ $ 125,000
LumaSense Technology Holdings Inc. [Member]
Business Acquisition [Line Items]
Schedule of components of the fair value of total consideration transferred	The components of the fair value of the total consideration transferred for our acquisition is as follows: ​ ​ ​ ​ ​ ​ LumaSense Cash paid for acquisition ​ $ 94,946 Cash acquired ​ (10,262) Total fair value of consideration transferred ​ $ 84,684
Schedule of estimated fair value of assets acquired and liabilities assumed	The following table summarizes the fair values of the assets acquired and liabilities assumed from our acquisition, including measurement period adjustments: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Preliminary: September 1, 2018 ​ Measurement Period Adjustments ​ Adjusted: September 1, 2018 Accounts and other receivable, net ​ $ 7,167 ​ $ - ​ $ 7,167 Inventories ​ 9,372 ​ ​ - ​ ​ 9,372 Property and equipment ​ 1,353 ​ ​ - ​ ​ 1,353 Goodwill ​ 48,032 ​ ​ (11,774) ​ ​ 36,258 Intangible assets ​ 26,000 ​ ​ 17,240 ​ ​ 43,240 Deferred income tax assets ​ 8,116 ​ ​ (1,785) ​ ​ 6,331 Other assets ​ 5,126 ​ ​ 878 ​ ​ 6,004 Total assets acquired ​ 105,166 ​ ​ 4,559 ​ ​ 109,725 Accounts payable ​ 5,734 ​ ​ - ​ ​ 5,734 Deferred income tax liabilities ​ 7,984 ​ ​ 3,715 ​ ​ 11,699 Other liabilities ​ 6,764 ​ ​ 844 ​ ​ 7,608 Total liabilities assumed ​ 20,482 ​ ​ 4,559 ​ ​ 25,041 Total fair value of net assets acquired ​ $ 84,684 ​ $ - ​ $ 84,684 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​
Summary of intangible assets	A summary of the intangible assets acquired, amortization method and estimated useful lives are as follows: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Amortization ​ ​ ​ LumaSense ​ Method ​ Useful Life Technology ​ $ 35,530 Straight-line 15 Customer relationships ​ 4,360 Straight-line 10 Tradename ​ 3,350 Straight-line 10 Total ​ $ 43,240

Revenue (Tables)

Revenue (Tables)	9 Months Ended
	Sep. 30, 2019
Revenue
Schedule of disaggregation of revenue	Disaggregation of Revenue The following table presents our net sales by market, inclusive of both products and services, which reflects a reclassification in prior periods to conform to the current presentation: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Three Months Ended September 30, ​ Nine Months Ended September 30, ​ ​ 2019 2018 2019 2018 ​ Semiconductor Equipment ​ $ 96,426 ​ $ 119,969 ​ $ 277,911 ​ $ 426,380 ​ Telecom & Networking ​ ​ 10,016 ​ ​ — ​ ​ 10,016 ​ ​ — ​ Data Center Computing ​ ​ 13,498 ​ ​ — ​ ​ 13,498 ​ ​ — ​ Industrial & Medical ​ 55,187 ​ 53,113 ​ 149,255 ​ 138,351 ​ Total ​ $ 175,127 ​ $ 173,082 ​ $ 450,680 ​ $ 564,731 ​ ​ The following table presents our net sales by geographic region, which includes a reclassification in prior periods to conform to the current presentation: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Three Months Ended September 30, ​ Nine Months Ended September 30, ​ 2019 ​ 2018 ​ 2019 ​ 2018 North America ​ $ 83,632 $ 85,728 ​ $ 203,531 $ 295,567 Asia ​ 66,157 ​ 61,691 ​ ​ 175,554 ​ 198,020 Europe ​ 25,008 ​ 25,538 ​ ​ 70,526 ​ 70,802 Other Countries ​ 330 ​ 125 ​ ​ 1,069 ​ 342 Total ​ $ 175,127 $ 173,082 ​ $ 450,680 $ 564,731 ​ The following table presents our net sales by extended warranty and service contracts recognized over time and our product and service revenue recognized at a point in time: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Three Months Ended September 30, ​ Nine Months Ended September 30, ​ ​ 2019 2018 2019 2018 ​ Product and service revenue recognized at point in time ​ $ 174,827 ​ $ 171,806 ​ $ 448,964 ​ $ 561,578 ​ Extended warranty and service contracts recognized over time ​ 300 ​ 1,276 ​ 1,716 ​ 3,153 ​ Total ​ $ 175,127 ​ $ 173,082 ​ $ 450,680 ​ $ 564,731 ​

Disposed and Discontinued Ope_2

Disposed and Discontinued Operations (Tables)	9 Months Ended
	Sep. 30, 2019
Disposed and Discontinued Operations
Schedule of disposal groups, including discontinued operations	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Three Months Ended September 30, ​ Nine Months Ended September 30, ​ ​ 2019 2018 2019 2018 ​ Sales ​ $ — ​ $ — ​ $ — ​ $ — ​ Cost of sales ​ (700) ​ — ​ (900) ​ (88) ​ Total operating expense ​ 133 ​ — ​ 514 ​ 31 ​ Operating income from discontinued operations ​ 567 ​ — ​ 386 ​ 57 ​ Other income (expense) ​ (84) ​ (258) ​ 10,835 ​ (261) ​ Income (loss) from discontinued operations before income taxes ​ 483 ​ (258) ​ 11,221 ​ (204) ​ Provision (benefit) for income taxes ​ 108 ​ 113 ​ 2,531 ​ 22 ​ Income (loss) from discontinued operations, net of income taxes ​ $ 375 ​ $ (371) ​ $ 8,690 ​ $ (226) ​ ​ Assets and Liabilities of discontinued operations within the Condensed Consolidated Balance Sheets are comprised of the following: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ September 30, ​ December 31, ​ ​ 2019 2018 ​ Cash and cash equivalents ​ $ — ​ $ 5,251 ​ Other current assets ​ ​ — ​ ​ 406 ​ Inventories ​ ​ 84 ​ ​ 198 ​ Current assets of discontinued operations ​ $ 84 ​ $ 5,855 ​ ​ ​ ​ ​ ​ ​ ​ ​ Other assets ​ $ — ​ $ 67 ​ Deferred income tax assets ​ 755 ​ 5,917 ​ Non-current assets of discontinued operations ​ $ 755 ​ $ 5,984 ​ ​ ​ ​ ​ ​ ​ ​ ​ Accounts payable and other accrued expenses ​ $ — ​ $ 350 ​ Accrued warranty ​ 910 ​ 4,936 ​ Current liabilities of discontinued operations ​ $ 910 ​ $ 5,286 ​ ​ ​ ​ ​ ​ ​ ​ ​ Accrued warranty ​ $ 903 ​ $ 10,429 ​ Other liabilities ​ 142 ​ 286 ​ Non-current liabilities of discontinued operations ​ $ 1,045 ​ $ 10,715 ​

Income Taxes (Tables)

Income Taxes (Tables)	9 Months Ended
	Sep. 30, 2019
Income Taxes
Schedule of tax expense and the effective tax rate for our income from continuing operations	The following table sets out the tax expense and the effective tax rate for our income from continuing operations: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Three Months Ended September 30, ​ Nine Months Ended September 30, ​ ​ 2019 2018 2019 2018 ​ Income from continuing operations, before income taxes ​ $ 10,751 ​ $ 40,263 ​ $ 49,835 ​ $ 151,925 ​ Provision for income taxes ​ ​ 3,495 ​ ​ 5,106 ​ ​ 3,819 ​ ​ 23,998 ​ Effective tax rate ​ ​ 32.5 % ​ 12.7 % ​ 7.7 % ​ 15.8 %

Earnings Per Share (Tables)

Earnings Per Share (Tables)	9 Months Ended
	Sep. 30, 2019
Earnings Per Share
Reconciliation of the weighted-average shares outstanding used in the calculation of basic and diluted EPS	The following is a reconciliation of the weighted-average shares outstanding used in the calculation of basic and diluted EPS for the three and nine months ended September 30, 2019 and 2018: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Three Months Ended September 30, ​ Nine Months Ended September 30, ​ ​ 2019 2018 2019 2018 ​ Income from continuing operations ​ $ 7,256 ​ $ 35,157 ​ $ 46,016 ​ $ 127,927 ​ Income from continuing operations attributable to noncontrolling interest ​ 10 ​ 7 ​ 29 ​ 82 ​ Income from continuing operations attributable to Advanced Energy Industries, Inc. ​ $ 7,246 ​ $ 35,150 ​ $ 45,987 ​ $ 127,845 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Basic weighted-average common shares outstanding ​ 38,313 ​ 38,970 ​ 38,258 ​ 39,309 ​ Assumed exercise of dilutive stock options and restricted stock units ​ 176 ​ 225 ​ 199 ​ 285 ​ Diluted weighted-average common shares outstanding ​ 38,489 ​ 39,195 ​ 38,457 ​ 39,594 ​ Continuing operations: ​ ​ ​ ​ ​ Basic earnings per share ​ $ 0.19 ​ $ 0.90 ​ $ 1.20 ​ $ 3.25 ​ Diluted earnings per share ​ $ 0.19 ​ $ 0.90 ​ $ 1.20 ​ $ 3.23 ​ ​
Schedule of stock options and restricted units excluded in the computation of diluted earnings per share	The following restricted stock units were excluded in the computation of diluted earnings per share because they were anti-dilutive: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Three Months Ended September 30, ​ Nine Months Ended September 30, ​ ​ 2019 2018 2019 2018 ​ Restricted stock units 4 1 1 — ​
Schedule of repurchase of shares of common stock	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Three Months Ended September 30, ​ Nine Months Ended September 30, ​ ​ 2019 2018 2019 2018 ​ Amount paid to repurchase shares ​ $ — ​ $ 30,962 ​ $ — ​ $ 69,021 ​ Number of shares repurchased ​ — ​ 533 ​ — ​ 1,121 ​ Average repurchase price per share ​ $ — ​ $ 58.12 ​ $ — ​ $ 61.57 ​

Marketable Securities and Ass_2

Marketable Securities and Assets Measured at Fair Value (Tables)	9 Months Ended
	Sep. 30, 2019
Marketable Securities and Assets Measured at Fair Value
Schedule of composition of our marketable securities	Our marketable securities consist of certificates of deposit as follows: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ September 30, 2019 ​ December 31, 2018 ​ Cost Fair Value Cost Fair Value Total marketable securities ​ $ 741 ​ $ 747 ​ $ 2,463 ​ $ 2,470
Schedule of maturities of our marketable securities available for sale	The maturities of our marketable securities available for sale as of September 30, 2019 are as follows: ​ ​ ​ ​ ​ ​ ​ ​ ​ Earliest ​ Latest Certificates of deposit 10/14/2019 to 7/28/2020
Schedule of fair value, assets measured on recurring basis	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ September 30, 2019 Level 1 Level 2 Level 3 Total Total marketable securities ​ $ — ​ $ 747 ​ $ — ​ $ 747 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, 2018 Level 1 Level 2 Level 3 Total Total marketable securities ​ $ — ​ $ 2,470 ​ $ — ​ $ 2,470

Derivative Financial Instrume_2

Derivative Financial Instruments (Tables)	9 Months Ended
	Sep. 30, 2019
Derivative Financial Instruments
Schedule of derivative instruments, gain (loss)	During the three and nine months ended September 30, 2019 and 2018 the gains and losses recorded related to the foreign currency exchange contracts are as follows: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Three Months Ended September 30, ​ Nine Months Ended September 30, ​ ​ 2019 2018 2019 2018 ​ Foreign currency loss from foreign currency exchange contracts ​ $ — ​ $ — ​ $ — ​ $ (750) ​

Accounts and Other Receivable (

Accounts and Other Receivable (Tables)	9 Months Ended
	Sep. 30, 2019
Accounts and Other Receivable
Schedule of accounts and other receivable	Accounts and other receivable are recorded at net realizable value. Components of accounts and other receivable, net of reserves, are as follows: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ September 30, ​ December 31, ​ 2019 2018 Amounts billed, net ​ $ 233,464 ​ $ 80,709 Unbilled receivables ​ ​ 16,687 ​ 19,733 Total receivables, net ​ $ 250,151 ​ $ 100,442

Inventories (Tables)

Inventories (Tables)	9 Months Ended
	Sep. 30, 2019
Inventories
Schedule of components of inventories	Our inventories are valued at the lower of cost or net realizable value and computed on a first-in, first-out (FIFO) basis. Components of inventories are as follows: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ September 30, ​ December 31, ​ ​ 2019 2018 ​ Parts and raw materials ​ $ 141,672 ​ $ 76,647 ​ Work in process ​ 13,810 ​ 6,644 ​ Finished goods ​ 85,217 ​ 14,696 ​ Total ​ $ 240,699 ​ $ 97,987 ​

Property and Equipment (Tables)

Property and Equipment (Tables)	9 Months Ended
	Sep. 30, 2019
Property and Equipment
Schedule of details of property and equipment	Property and equipment, net is comprised of the following: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ September 30, ​ December 31, ​ ​ 2019 2018 ​ Buildings and land ​ $ 1,633 ​ $ 1,737 ​ Machinery and equipment ​ 93,657 ​ 41,330 ​ Computer and communication equipment ​ 31,204 ​ 24,051 ​ Furniture and fixtures ​ 4,574 ​ 3,203 ​ Vehicles ​ 1,154 ​ 282 ​ Leasehold improvements ​ 33,666 ​ 20,593 ​ Construction in process ​ 6,777 ​ 867 ​ ​ ​ 172,665 ​ 92,063 ​ Less: Accumulated depreciation ​ (68,097) ​ (60,794) ​ Property and equipment, net ​ $ 104,568 ​ $ 31,269 ​
Schedule of depreciation expense recorded in continuing operations	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Three Months Ended September 30, ​ Nine Months Ended September 30, ​ ​ 2019 2018 2019 2018 ​ Depreciation expense ​ $ 3,903 ​ $ 2,134 ​ $ 8,452 ​ $ 5,530 ​

Goodwill (Tables)

Goodwill (Tables)	9 Months Ended
	Sep. 30, 2019
Goodwill and Intangible Assets
Schedule of the changes in goodwill	The following summarizes the changes in goodwill during the nine months ended September 30, 2019: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Effect of ​ ​ ​ Beginning ​ ​ ​ ​ ​ Changes in Ending ​ ​ Balance ​ Adjustments Additions Exchange Rates ​ Balance September 30, 2019 ​ $ 101,900 ​ $ (11,774) ​ $ 143,262 ​ $ (1,188) ​ $ 232,200

Intangible Assets (Tables)

Intangible Assets (Tables)	9 Months Ended
	Sep. 30, 2019
Goodwill and Intangible Assets
Schedule of intangible assets	Intangible assets consisted of the following as of September 30, 2019 and December 31, 2018: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Gross Carrying Accumulated Net Carrying September 30, 2019 ​ Amount ​ Amortization ​ Amount Technology ​ $ 84,814 ​ $ (11,337) ​ $ 73,477 Customer relationships ​ 108,176 ​ (15,745) ​ 92,431 Trademarks and other ​ 25,766 ​ (2,073) ​ 23,693 Total ​ $ 218,756 ​ $ (29,155) ​ $ 189,601 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Gross Carrying Accumulated Net Carrying December 31, 2018 ​ Amount ​ Amortization ​ Amount Technology ​ $ 39,879 ​ $ (7,927) ​ $ 31,952 Customer relationships ​ 35,509 ​ (13,484) ​ 22,025 Trademarks and other ​ 2,501 ​ (1,568) ​ 933 Total ​ $ 77,889 ​ $ (22,979) ​ $ 54,910
Schedule of amortization expense relating to intangible assets	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Three Months Ended September 30, ​ Nine Months Ended September 30, ​ ​ 2019 2018 2019 2018 ​ Amortization expense ​ $ 3,002 ​ $ 1,437 ​ $ 6,849 ​ $ 3,958 ​
Schedule of expected future amortization expense	Estimated amortization expense related to intangibles is as follows: ​ ​ ​ ​ ​ Year Ending December 31, ​ ​ 2019 (remaining) ​ $ 5,555 2020 ​ 20,307 2021 ​ 20,209 2022 ​ 19,953 2023 ​ 19,935 Thereafter ​ 103,642 Total ​ $ 189,601

Restructuring Costs (Tables)

Restructuring Costs (Tables)	9 Months Ended
	Sep. 30, 2019
Restructuring Costs
Schedule of restructuring and related costs	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Three Months ​ Nine Months ​ Cumulative Cost ​ ​ ​ Ended September 30, ​ Ended September 30, ​ Through September 30, ​ ​ ​ 2019 ​ 2019 ​ 2019 ​ Severance and related charges $ 150 $ 1,868 $ 6,107 Facility relocation and closure charges ​ 2 ​ 1,752 ​ 1,752 Total restructuring charges $ 152 $ 3,620 $ 7,859
Schedule of restructuring reserve by type of cost	​ The following table summarizes our restructuring liabilities at September 30, 2019: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Cost ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Incurred ​ Cost Paid ​ Effect of ​ ​ ​ ​ ​ Balance at ​ and ​ or ​ Changes in ​ Balance at ​ ​ December 31, ​ Charged to ​ Otherwise ​ Exchange ​ September 30, ​ ​ 2018 ​ Expense ​ Settled ​ Rates ​ 2019 Total restructuring liabilities ​ $ 3,806 ​ $ 3,620 ​ $ (5,560) ​ $ 1 ​ $ 1,867

Warranties (Tables)

Warranties (Tables)	9 Months Ended
	Sep. 30, 2019
Warranties
Schedule of changes in accrued product warranties	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Three Months Ended September 30, ​ Nine Months Ended September 30, ​ ​ 2019 2018 2019 2018 ​ Balances at beginning of period ​ $ 3,263 ​ $ 1,981 ​ $ 2,084 ​ $ 2,312 ​ Acquired warranty ​ 3,618 ​ 213 ​ 4,818 ​ 305 ​ Increases to accruals ​ 286 ​ 436 ​ 890 ​ 920 ​ Warranty expenditures ​ (414) ​ (590) ​ (1,045) ​ (1,492) ​ Effect of changes in exchange rates ​ (11) ​ (2) ​ (5) ​ (7) ​ Balances at end of period ​ $ 6,742 ​ $ 2,038 ​ $ 6,742 ​ $ 2,038 ​

Leases (Tables)

Leases (Tables)	9 Months Ended
	Sep. 30, 2019
Leases
Schedule of maturities of lease liabilities	​ Maturities of our lease liabilities for all operating leases at September 30, 2019 are as follows: ​ ​ ​ ​ ​ Year Ending December 31, ​ 2019 (remaining) ​ $ 4,626 2020 ​ 20,196 2021 ​ 18,527 2022 ​ 13,713 2023 ​ 11,080 Thereafter ​ 71,003 Total lease payments ​ $ 139,145 Less: Interest ​ (26,396) Present value of lease liabilities ​ $ 112,749
Schedule of additional lease information	The weighted average remaining lease term and discount rate for all our operating leases as of September 30, 2019 were as follows: ​ ​ ​ ​ ​ ​ ​ ​ Weighted Average ​ ​ ​ Remaining Lease ​ Weighted Average ​ ​ Term ​ Discount Rate Operating leases 8.7 4.03 % ​ Cash paid for amounts included in the measurement of lease liabilities for the nine months ended September 30, 2019 was as follows: ​ ​ ​ ​ ​ ​ Cash Outflow Operating leases ​ $ 8,850

Pension Liability (Tables)

Pension Liability (Tables)	9 Months Ended
	Sep. 30, 2019
Pension Liability
Schedule of net funded status	The net pension liability is included in Other long-term liabilities in our Consolidated Balance Sheets as follows: ​ ​ ​ ​ ​ ​ ​ ​ ​ September 30, December 31, ​ ​ 2019 ​ 2018 Pension liability ​ $ 66,450 ​ $ 19,266
Schedule of net benefit costs	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Three Months Ended September 30, ​ Nine Months Ended September 30, ​ ​ 2019 2018 2019 2018 ​ Service cost ​ $ 124 ​ $ — ​ $ 124 ​ $ — ​ Interest cost ​ ​ 274 ​ ​ 205 ​ ​ 668 ​ ​ 637 ​ Expected return on plan assets ​ (160) ​ ​ (151) ​ ​ (496) ​ ​ (470) ​ Amortization of actuarial gains and losses ​ 90 ​ ​ 64 ​ ​ 323 ​ ​ 333 ​ Net periodic pension cost ​ $ 328 ​ $ 118 ​ $ 619 ​ $ 500 ​

Stock-Based Compensation (Table

Stock-Based Compensation (Tables)	9 Months Ended
	Sep. 30, 2019
Stock-Based Compensation
Schedule of stock-based compensation	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Three Months Ended September 30, ​ Nine Months Ended September 30, ​ ​ 2019 2018 2019 2018 ​ Stock-based compensation expense ​ $ 917 ​ $ 1,024 ​ $ 5,053 ​ $ 7,461 ​
Summary of stock option activity	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Three Months Ended September 30, 2019 ​ Nine Months Ended September 30, 2019 ​ ​ ​ Weighted- ​ Weighted- ​ ​ ​ ​ ​ Average ​ ​ ​ Average ​ ​ ​ ​ ​ Grant Date ​ ​ ​ Grant Date ​ ​ ​ Number of RSUs ​ Fair Value ​ Number of RSUs ​ Fair Value ​ RSUs outstanding at beginning of period 553 ​ $ 56.23 352 ​ $ 58.17 RSUs granted 18 ​ $ 57.01 377 ​ $ 52.18 RSUs vested (7) ​ $ 27.69 (153) ​ $ 50.90 RSUs forfeited (30) ​ $ 58.27 (42) ​ $ 51.74 RSUs outstanding at end of period 534 ​ $ 56.52 534 ​ $ 56.52 ​ Changes in the outstanding stock option awards during the three and nine months ended September 30, 2019 were as follows: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Three Months Ended September 30, 2019 ​ Nine Months Ended September 30, 2019 ​ ​ ​ Weighted- ​ Weighted- ​ ​ ​ ​ ​ Average ​ ​ ​ Average ​ ​ ​ Number of ​ Exercise Price ​ Number of ​ Exercise Price ​ ​ ​ Options ​ per Share ​ Options ​ per Share ​ Options outstanding at beginning of period 213 ​ $ 21.50 230 ​ $ 20.73 Options exercised (21) ​ $ 22.90 (37) ​ $ 18.03 Options expired (1) ​ $ 11.21 (2) ​ $ 8.95 Options outstanding at end of period 191 ​ $ 21.37 191 ​ $ 21.37

Related Party Transactions (Tab

Related Party Transactions (Tables)	9 Months Ended
	Sep. 30, 2019
Related Party Transactions
Schedule of related party transactions	Members of our Board of Directors hold various executive positions and serve as directors at other companies, including companies that are our customers. During the three and nine months ended September 30, 2019 and 2018, we engaged in the following transactions with companies related to members of our Board of Directors, as described below: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Three Months Ended September 30, ​ Nine Months Ended September 30, ​ ​ 2019 2018 2019 2018 ​ Sales to related parties ​ $ 287 ​ $ — ​ $ 1,299 ​ $ 389 ​ Number of related party customers ​ 1 ​ — ​ 1 ​ 1 ​ Our accounts receivable balance from related party customers with outstanding balances as of September 30, 2019 and December 31, 2018 is as follows: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ September 30, ​ December 31, ​ 2019 2018 Accounts receivable from related parties ​ $ 41 ​ $ 109 Number of related party customers ​ 1 ​ 1

Significant Customer Informat_2

Significant Customer Information (Tables)	9 Months Ended
	Sep. 30, 2019
Significant Customer Information
Schedule of revenue by major customers by reporting segments	The following table summarizes sales, and percentages of sales, by customers that individually accounted for 10% or more of our sales for the three and nine months ended September 30, 2019 and 2018: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Three Months Ended September 30, ​ 2019 ​ 2018 Applied Materials, Inc. ​ $ 38,957 22.2 % ​ $ 60,546 35.0 % LAM Research ​ 21,991 12.6 % ​ 19,878 11.5 % ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Nine Months Ended September 30, ​ 2019 ​ 2018 Applied Materials, Inc. ​ $ 108,978 24.2 % ​ $ 198,159 35.1 % LAM Research ​ 61,364 13.6 % ​ 92,368 16.4 % ​ The following table summarizes the accounts receivable balances, and percentages of the total accounts receivable, for customers that individually accounted for 10% or more of accounts receivable as of September 30, 2019 and December 31, 2018: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ September 30, December 31, ​ ​ 2019 ​ 2018 Applied Materials, Inc. ​ $ 30,669 12.3 % $ 34,301 34.2 % LAM Research ​ * * % 12,181 12.1 %

Credit Facility (Tables)

Credit Facility (Tables)	9 Months Ended
	Sep. 30, 2019
Credit Facility
Schedule of debt obligation	​ ​ ​ ​ ​ ​ ​ ​ ​ September 30, ​ December 31, ​ 2019 2018 Debt: ​ ​ ​ ​ ​ ​ Term Loan Facility ​ $ 345,625 ​ $ — Revolving Facility ​ ​ — ​ ​ — Other debt issuance costs ​ ​ (2,356) ​ ​ — Total debt ​ ​ 343,269 ​ ​ — Less current portion of debt ​ ​ (17,500) ​ ​ — Total long-term debt ​ $ 325,769 ​ $ —
Schedule of contractual maturities of the Company's debt obligations	​ ​ ​ ​ ​ Amount 2019 (remaining) ​ $ 4,375 2020 ​ ​ 17,500 2021 ​ ​ 17,500 2022 ​ ​ 17,500 2023 ​ ​ 17,500 2024 ​ ​ 271,250
Schedule of interest expense and unused line of credit fees	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Three Months Ended September 30, ​ Nine Months Ended September 30, ​ ​ 2019 2018 2019 2018 ​ Interest expense ​ $ 703 ​ $ — ​ $ 703 ​ $ — ​ Amortization of debt issuance costs ​ ​ 45 ​ ​ — ​ ​ 45 ​ ​ — ​ Unused line of credit fees and other ​ ​ 60 ​ ​ 57 ​ ​ 179 ​ ​ 171 ​ Total interest expense ​ $ 808 ​ $ 57 ​ $ 927 ​ $ 171 ​

Basis of Presentation (Details)

Basis of Presentation (Details) - USD ($) $ in Thousands	Sep. 30, 2019	Jun. 30, 2019	Jan. 01, 2019
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Operating lease right-of-use assets	$ 111,193
Operating Lease, Liability	$ 112,749
Accounting Standards Update 2016-02 [Member]
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Operating lease right-of-use assets		$ 111,200	$ 38,200
Operating Lease, Liability		$ 112,700	$ 38,400

Business Acquisitions - Artesyn

Business Acquisitions - Artesyn's Embedded Power Business (Details) - USD ($) $ in Thousands	Sep. 30, 2019	Sep. 10, 2019
Revolving Facility [Member]
Business Acquisition [Line Items]
Line of credit facility, borrowing capacity	$ 500,000
Term Loan Facility [Member]
Business Acquisition [Line Items]
Line of credit facility, borrowing capacity	350,000
Artesyn's Embedded Power Business [Member]
Business Acquisition [Line Items]
Purchase price	$ 367,798	$ 367,798

Business Acquisitions - Conside

Business Acquisitions - Consideration Transferred (Details) - USD ($) $ in Thousands	1 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 10, 2019	Sep. 01, 2018
Artesyn's Embedded Power Business [Member]
Business Acquisition [Line Items]
Cash paid for acquisition	$ 389,023
Non-cash consideration	2,000
Total fair value of consideration transferred	391,023
Less cash acquired	(23,225)
Total purchase price	$ 367,798		$ 367,798
LumaSense Technology Holdings Inc. [Member]
Business Acquisition [Line Items]
Cash paid for acquisition		$ 94,946
Total fair value of consideration transferred		84,684
Less cash acquired		$ (10,262)
Total purchase price				$ 84,684

Business Acquisitions - Assets

Business Acquisitions - Assets Acquired and Liabilities Assumed (Details) - USD ($) $ in Thousands	Sep. 30, 2019	Sep. 10, 2019	Sep. 01, 2018
Artesyn's Embedded Power Business [Member]
Business Acquisition [Line Items]
Accounts and other receivable, net		$ 128,221
Inventories		140,678
Property and equipment		65,016
Operating lease right-of-use assets		60,217
Goodwill		143,262
Intangible assets		125,000
Deferred income tax assets		14,767
Other assets		61,511
Total assets acquired		738,672
Accounts payable		144,652
Operating lease liability		59,634
Pension liability		48,494
Deferred income tax liabilities		37,218
Other liabilities		80,876
Total liabilities assumed		370,874
Total fair value of net assets acquired	$ 367,798	$ 367,798
LumaSense Technology Holdings Inc. [Member]
Business Acquisition [Line Items]
Accounts and other receivable, net			$ 7,167
Inventories			9,372
Property and equipment			1,353
Goodwill			36,258
Intangible assets			43,240
Deferred income tax assets			6,331
Other assets			6,004
Total assets acquired			109,725
Accounts payable			5,734
Deferred income tax liabilities			11,699
Other liabilities			7,608
Total liabilities assumed			25,041
Total fair value of net assets acquired			84,684
LumaSense Technology Holdings Inc. [Member] | Preliminary [Member]
Business Acquisition [Line Items]
Accounts and other receivable, net			7,167
Inventories			9,372
Property and equipment			1,353
Goodwill			48,032
Intangible assets			26,000
Deferred income tax assets			8,116
Other assets			5,126
Total assets acquired			105,166
Accounts payable			5,734
Deferred income tax liabilities			7,984
Other liabilities			6,764
Total liabilities assumed			20,482
Total fair value of net assets acquired			84,684
LumaSense Technology Holdings Inc. [Member] | Measurement Period Adjustments [Member]
Business Acquisition [Line Items]
Goodwill			(11,774)
Intangible assets			17,240
Deferred income tax assets			(1,785)
Other assets			878
Total assets acquired			4,559
Deferred income tax liabilities			3,715
Other liabilities			844
Total liabilities assumed			$ 4,559

Business Acquisitions - Intangi

Business Acquisitions - Intangible Assets Acquired (Details) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2019	Sep. 10, 2019	Sep. 01, 2018
Artesyn's Embedded Power Business [Member]
Acquired Finite-Lived Intangible Assets [Line Items]
Amortizable intangible assets:		$ 125,000
Artesyn's Embedded Power Business [Member] | Technology-Based Intangible Assets [Member]
Acquired Finite-Lived Intangible Assets [Line Items]
Amortizable intangible assets:		30
Useful Life	5 years
Artesyn's Embedded Power Business [Member] | Customer Relationships [Member]
Acquired Finite-Lived Intangible Assets [Line Items]
Amortizable intangible assets:		75
Useful Life	15 years
Artesyn's Embedded Power Business [Member] | Tradename [Member]
Acquired Finite-Lived Intangible Assets [Line Items]
Amortizable intangible assets:		$ 20
Useful Life	10 years
LumaSense Technology Holdings Inc. [Member]
Acquired Finite-Lived Intangible Assets [Line Items]
Amortizable intangible assets:			$ 43,240
LumaSense Technology Holdings Inc. [Member] | Technology-Based Intangible Assets [Member]
Acquired Finite-Lived Intangible Assets [Line Items]
Amortizable intangible assets:			35,530
Useful Life	15 years
LumaSense Technology Holdings Inc. [Member] | Customer Relationships [Member]
Acquired Finite-Lived Intangible Assets [Line Items]
Amortizable intangible assets:			4,360
Useful Life	10 years
LumaSense Technology Holdings Inc. [Member] | Tradename [Member]
Acquired Finite-Lived Intangible Assets [Line Items]
Amortizable intangible assets:			$ 3,350
Useful Life	10 years

Business Acquisitions - Unaudit

Business Acquisitions - Unaudited Pro Forma Results (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended						9 Months Ended
	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Sep. 30, 2019	Sep. 30, 2018
Business Acquisition, Pro Forma Information [Abstract]
Total sales, As Reported	$ 175,127			$ 173,082			$ 450,680	$ 564,731
Total sales, Pro Forma	292,669			333,050			863,190	1,037,113
Net income attributable to Advanced Energy Industries, Inc, As Reported	7,621			34,779			54,677	127,619
Net income attributable to Advanced Energy Industries, Inc., Pro Forma	11,095			36,887			58,615	135,994
Cost of goods sold	101,636			87,543			247,323	274,312
Selling, general and administrative	$ 36,401			$ 25,386			$ 93,027	$ 78,792
Earnings Per Share, Pro Forma [Abstract]
Basic earnings per share, As Reported	$ 0.20			$ 0.89			$ 1.43	$ 3.25
Basic earnings per share, Pro Forma	0.29			0.95			1.53	3.46
Diluted earnings per share, As Reported	0.20			0.89			1.42	3.23
Diluted earnings per share, Pro Forma	$ 0.29			$ 0.94			$ 1.52	$ 3.44
Net income	$ 7,631	$ 31,697	$ 15,378	$ 34,786	$ 46,405	$ 46,510	$ 54,706	$ 127,701
LumaSense Technology Holdings Inc. [Member]
Business Acquisition, Pro Forma Information [Abstract]
Total sales, As Reported	12,000						35,800
Earnings Per Share, Pro Forma [Abstract]
Net income	1,000						3,600
Artesyn's Embedded Power Business [Member]
Business Acquisition, Pro Forma Information [Abstract]
Total sales, As Reported	40,900						40,900
Earnings Per Share, Pro Forma [Abstract]
Net income	1,200						1,200
Artesyn's Embedded Power Business [Member] | Acquisition-related Costs [Member]
Business Acquisition, Pro Forma Information [Abstract]
Cost of goods sold	1,500						1,500
Selling, general and administrative	$ 6,400						$ 7,900

Revenue - Narrative (Details)

Revenue - Narrative (Details) - USD ($) $ in Millions	1 Months Ended	204 Months Ended
	May 31, 2019	Dec. 31, 2035	Sep. 30, 2019	Dec. 31, 2018
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Deferred revenue transferred to buyer during sale	$ 22
Deferred Service Revenue			$ 9.4	$ 33.4
Minimum [Member] | Subsequent Event [Member] | Scenario, Forecast [Member]
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Recognition of Deferred Revenue, Expected Annual Amount		$ 0.1
Maximum [Member] | Subsequent Event [Member] | Scenario, Forecast [Member]
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Recognition of Deferred Revenue, Expected Annual Amount		$ 1

Revenue - Revenue by product li

Revenue - Revenue by product line (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	$ 175,127	$ 173,082	$ 450,680	$ 564,731
North America [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	83,632	85,728	203,531	295,567
Asia [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	66,157	61,691	175,554	198,020
Europe [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	25,008	25,538	70,526	70,802
Other Countries [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	330	125	1,069	342
Semiconductor Equipment [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	96,426	119,969	277,911	426,380
Telecom And Networking [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	10,016		10,016
Data Center Computing [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	13,498		13,498
Industrial And Medical [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	$ 55,187	$ 53,113	$ 149,255	$ 138,351

Revenue - Extended Warranty Rev

Revenue - Extended Warranty Revenue (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	$ 175,127	$ 173,082	$ 450,680	$ 564,731
Transferred at Point in Time [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	174,827	171,806	448,964	561,578
Transferred over Time [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	$ 300	$ 1,276	$ 1,716	$ 3,153

Disposed and Discontinued Ope_3

Disposed and Discontinued Operations - Disposed Operations (Details) - Grid Tied Central Solar Inverter Services Business[Member] - Disposal Group, Disposed of by Sale, Not Discontinued Operations [Member] - Bold Renewables Holdings, LLC [Member]	1 Months Ended
	May 31, 2019USD ($)
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Disposed operations of services	$ 1
Loan	2,800,000
Amount available to borrow	$ 5,250,000
Loan term	10 years
Disposed operation of discount eligibility	30 days
Disposed operations recognized reduction to gain on sale	$ 2,300,000
Non-cash gain, net of tax expense, from discontinued operations	8,600,000
Continuing Operations [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Disposed operations of extended warranty service obligation	22,000,000
Non cash gain from continuing operations	14,800,000
Discontinued Operations [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Disposed operations of reduced liabilities held in discontinued operations	10,900,000
Tax expense from discontinued operations	$ 2,400,000
Interest Rate, First Seven Years [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Disposed operations of interest (percent)	0.00%
Interest Rate, Thereafter [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Disposed operations of interest (percent)	5.00%
Discounts On First Three Years [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Disposed operations of early payment discounts (percent)	50.00%
Discounts On Year Four And Five [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Disposed operations of early payment discounts (percent)	45.00%
Discounts Thereafter [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Disposed operations of early payment discounts (percent)	40.00%

Disposed and Discontinued Ope_4

Disposed and Discontinued Operations - Statement of Operations for Discontinued Operations (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Disposed and Discontinued Operations
Cost of sales	$ (700)		$ (900)	$ (88)
Total operating expense	133		514	31
Operating income from discontinued operations	567		386	57
Other income (expense)	(84)	$ (258)		(261)
Other income (expense)			10,835
Income (loss) from discontinued operations before income taxes	483	(258)	11,221	(204)
Provision (benefit) for income taxes	108	113	2,531	22
Income (loss) from discontinued operations, net of income taxes	$ 375	$ (371)	$ 8,690	$ (226)

Disposed and Discontinued Ope_5

Disposed and Discontinued Operations - Assets and Liabilities of Discontinued Operations (Details) - USD ($) $ in Thousands	Sep. 30, 2019	Dec. 31, 2018	Sep. 30, 2018
Disposed and Discontinued Operations
Cash and cash equivalents		$ 5,251	$ 7,444
Other current assets		406
Inventories	$ 84	198
Current assets of discontinued operations	84	5,855
Other assets		67
Deferred income tax assets	755	5,917
Non-current assets of discontinued operations	755	5,984
Accounts payable and other accrued expenses		350
Accrued warranty	910	4,936
Current liabilities of discontinued operations	910	5,286
Accrued warranty	903	10,429
Other liabilities	142	286
Non-current liabilities of discontinued operations	$ 1,045	$ 10,715

Income Taxes - Schedule of tax

Income Taxes - Schedule of tax expense and effective tax rate for income from continuing operations (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Income Taxes
Income from continuing operations, before income taxes	$ 10,751	$ 40,263	$ 49,835	$ 151,925
Provision for income taxes	$ 3,495	$ 5,106	$ 3,819	$ 23,998
Effective tax rate	32.50%	12.70%	7.70%	15.80%

Income Taxes Narrative (Details

Income Taxes Narrative (Details)	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Income Taxes
Effective Income Tax Rate Reconciliation, at Federal Statutory Income Tax Rate, Percent	21.00%	21.00%	21.00%	21.00%

Earnings Per Share - Reconcilia

Earnings Per Share - Reconciliation of weighted-average shares outstanding used in calculation of basic and diluted EPS (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Earnings Per Share
Income from continuing operations	$ 7,256	$ 35,157	$ 46,016	$ 127,927
Income from continuing operations attributable to noncontrolling interest	10	7	29	82
Income from continuing operations attributable to Advanced Energy Industries, Inc.	$ 7,246	$ 35,150	$ 45,987	$ 127,845
Basic weighted-average common shares outstanding	38,313	38,970	38,258	39,309
Assumed exercise of dilutive stock options and restricted stock units	176	225	199	285
Diluted weighted-average common shares outstanding	38,489	39,195	38,457	39,594
Continuing Operations:
Basic earnings per share	$ 0.19	$ 0.90	$ 1.20	$ 3.25
Diluted earnings per share	$ 0.19	$ 0.90	$ 1.20	$ 3.23

Earnings Per Share - Schedule o

Earnings Per Share - Schedule of stock options and restricted units excluded in the computation of diluted earnings per share (Details) - shares shares in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019
Restricted Stock Units (RSUs) [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Stock options and restricted units excluded from the computation of diluted earnings per share because they were anti-dilutive	4	1	1

Earnings Per Share - Stock Buyb

Earnings Per Share - Stock Buyback (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended			9 Months Ended
	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Sep. 30, 2019	Sep. 30, 2018	May 03, 2018	Sep. 16, 2015
Earnings Per Share
Authorized amount							$ 150,000
Authorized program period repurchase				30 months
Authorized amount increase						$ 50,000
Remaining authorized repurchase amount				$ 24,900
Amount paid to repurchase shares	$ 30,962	$ 25,309	$ 12,750		$ 69,021
Number of shares repurchased	533				1,121
Average repurchase price per share	$ 58.12				$ 61.57

Marketable Securities and Ass_3

Marketable Securities and Assets Measured at Fair Value (Details) - USD ($) $ in Thousands	Sep. 30, 2019	Dec. 31, 2018
Marketable Securities and Assets Measured at Fair Value
Cost	$ 741	$ 2,463
Fair value	$ 747	$ 2,470

Marketable Securities and Ass_4

Marketable Securities and Assets Measured at Fair Value - Maturities of marketable securities available for sale (Details) - Certificates of Deposit [Member]	Sep. 30, 2019
Minimum [Member]
Debt Securities, Available-for-sale [Line Items]
Maturities of marketable securities, by date	Oct. 14, 2019
Maximum [Member]
Debt Securities, Available-for-sale [Line Items]
Maturities of marketable securities, by date	Jul. 28, 2020

Marketable Securities and Ass_5

Marketable Securities and Assets Measured at Fair Value - Fair Value of Marketable Securities (Details) - USD ($) $ in Thousands	3 Months Ended	9 Months Ended
	Sep. 30, 2019	Sep. 30, 2019	Dec. 31, 2018
Debt Securities, Available-for-sale [Line Items]
Transfers from level 1 to level 2, Assets	$ 0	$ 0
Transfers from level 1 to level 2, Liabilities	0	0
Transfers from level 2 to level 1, Assets	0	0
Transfers from level 2 to level 1, Liabilities	0	0
Transfers in or out, Assets	0	0
Transfers in or out, Liabilities	0	0
Fair Value, Measurements, Recurring [Member]
Debt Securities, Available-for-sale [Line Items]
Assets, Fair Value Disclosure	747	747	$ 2,470
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 2 [Member]
Debt Securities, Available-for-sale [Line Items]
Assets, Fair Value Disclosure	$ 747	$ 747	$ 2,470

Derivative Financial Instrume_3

Derivative Financial Instruments (Details) $ in Thousands	9 Months Ended
	Sep. 30, 2018USD ($)
Foreign Exchange [Member]
Derivative [Line Items]
Foreign currency loss from foreign currency exchange contracts	$ (750)

Accounts and Other Receivable_2

Accounts and Other Receivable (Details) - USD ($) $ in Thousands	Sep. 30, 2019	Dec. 31, 2018
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total receivables, net	$ 250,151	$ 100,442
Amounts billed, net
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total receivables, net	233,464	80,709
Unbilled receivables
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total receivables, net	$ 16,687	$ 19,733

Inventories (Details)

Inventories (Details) - USD ($) $ in Thousands	Sep. 30, 2019	Dec. 31, 2018
Inventories
Parts and raw materials	$ 141,672	$ 76,647
Work in process	13,810	6,644
Finished goods	85,217	14,696
Total	$ 240,699	$ 97,987

Property and Equipment - Detail

Property and Equipment - Details of property and equipment (Details) - USD ($) $ in Thousands	Sep. 30, 2019	Dec. 31, 2018
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	$ 172,665	$ 92,063
Less: Accumulated depreciation	(68,097)	(60,794)
Property and equipment, net	104,568	31,269
Buildings and Land [Member]
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	1,633	1,737
Machinery and Equipment [Member]
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	93,657	41,330
Computer and Communication Equipment [Member]
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	31,204	24,051
Furniture and Fixtures [Member]
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	4,574	3,203
Vehicles [Member]
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	1,154	282
Leasehold Improvements [Member]
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	33,666	20,593
Construction in Process [Member]
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	$ 6,777	$ 867

Property and Equipment - Deprec

Property and Equipment - Depreciation expense recorded in continuing operations (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Property and Equipment
Depreciation expense	$ 3,903	$ 2,134	$ 8,452	$ 5,530

Goodwill - Schedule of the chan

Goodwill - Schedule of the changes in goodwill (Details) $ in Thousands	9 Months Ended
	Sep. 30, 2019USD ($)
Goodwill and Intangible Assets
Beginning Balance	$ 101,900
Adjustments	(11,774)
Additions	143,262
Effect of Changes in Exchange Rates	(1,188)
Ending Balance	$ 232,200

Intangible Assets - Schedule of

Intangible Assets - Schedule of intangible assets (Details) - USD ($) $ in Thousands	Sep. 30, 2019	Dec. 31, 2018
Finite-Lived Intangible Assets [Line Items]
Finite-Lived Intangible Assets, Gross	$ 218,756	$ 77,889
Finite-Lived Intangible Assets, Accumulated Amortization	(29,155)	(22,979)
Finite-lived intangible assets, net	189,601	54,910
Technology Equipment [Member]
Finite-Lived Intangible Assets [Line Items]
Finite-Lived Intangible Assets, Gross	84,814	39,879
Finite-Lived Intangible Assets, Accumulated Amortization	(11,337)	(7,927)
Finite-lived intangible assets, net	73,477	31,952
Customer Relationships [Member]
Finite-Lived Intangible Assets [Line Items]
Finite-Lived Intangible Assets, Gross	108,176	35,509
Finite-Lived Intangible Assets, Accumulated Amortization	(15,745)	(13,484)
Finite-lived intangible assets, net	92,431	22,025
Trademarks and other [Member]
Finite-Lived Intangible Assets [Line Items]
Finite-Lived Intangible Assets, Gross	25,766	2,501
Finite-Lived Intangible Assets, Accumulated Amortization	(2,073)	(1,568)
Finite-lived intangible assets, net	$ 23,693	$ 933

Intangible Assets - Schedule _2

Intangible Assets - Schedule of amortization expense relating to intangible assets (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Goodwill and Intangible Assets
Amortization expense	$ 3,002	$ 1,437	$ 6,849	$ 3,958

Intangible Assets - Schedule _3

Intangible Assets - Schedule of Finite-Lived Intangible Assets, Future Amortization Expense (Details) - USD ($) $ in Thousands	Sep. 30, 2019	Dec. 31, 2018
Goodwill and Intangible Assets
2019 (remaining)	$ 5,555
2020	20,307
2021	20,209
2022	19,953
2023	19,935
Thereafter	103,642
Finite-lived intangible assets, net	$ 189,601	$ 54,910

Restructuring Costs - Schedule

Restructuring Costs - Schedule of Restructuring Reserve by Cost Type (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended		21 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019
Restructuring Cost and Reserve [Line Items]
Restructuring expense	$ 152	$ 403	$ 3,620	$ 403	$ 7,859
Severance and related charges
Restructuring Cost and Reserve [Line Items]
Restructuring expense	150		1,868		6,107
Facility relocation and closure charges
Restructuring Cost and Reserve [Line Items]
Restructuring expense	$ 2		$ 1,752		$ 1,752

Restructuring Costs - Restructu

Restructuring Costs - Restructuring liabilities (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended		21 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019
Restructuring Reserve [Roll Forward]
Beginning balance			$ 3,806
Cost incurred and charged to expense	$ 152	$ 403	3,620	$ 403	$ 7,859
Cost paid or otherwise settled			(5,560)
Effect of change in exchange rates			1
Ending balance	$ 1,867		$ 1,867		$ 1,867

Warranties - Narrative (Details

Warranties - Narrative (Details)	9 Months Ended
	Sep. 30, 2019
Minimum [Member]
Product Liability Contingency [Line Items]
Standard Product Warranty Term	12 months
Maximum [Member]
Product Liability Contingency [Line Items]
Standard Product Warranty Term	24 months

Warranties - Changes in accrued

Warranties - Changes in accrued product warranties (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Movement in Standard Product Warranty Accrual [Roll Forward]
Balances at beginning of period	$ 3,263	$ 1,981	$ 2,084	$ 2,312
Acquired warranty	3,618	213	4,818	305
Increases to accruals	286	436	890	920
Warranty expenditures	(414)	(590)	(1,045)	(1,492)
Effect of changes in exchange rates	(11)	(2)	(5)	(7)
Balances at end of period	$ 6,742	$ 2,038	$ 6,742	$ 2,038

Leases - Operating lease maturi

Leases - Operating lease maturity schedule (Details) $ in Thousands	Sep. 30, 2019USD ($)
Leases
2019 (remaining)	$ 4,626
2020	20,196
2021	18,527
2022	13,713
2023	11,080
Thereafter	71,003
Total lease payments	139,145
Less: Interest	(26,396)
Present value of lease liabilities	$ 112,749

Leases - Additional lease cost

Leases - Additional lease cost information (Details) $ in Thousands	9 Months Ended
	Sep. 30, 2019USD ($)
Leases
Weighted Average Remaining Lease Term	8 years 8 months 12 days
Weighted Average Discount Rate	4.03%
Operating leases	$ 8,850

Pension Liability (Details)

Pension Liability (Details) - USD ($) $ in Thousands	Sep. 30, 2019	Dec. 31, 2018
Defined Benefit Plan Disclosure [Line Items]
Pension liability	$ 66,450	$ 19,266
Payments through April 30, 2024 [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Expected Future Employer Contributions, Next Fiscal Year	800
Payments from May 1, 2024 through November 30, 2033 [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Expected Future Employer Contributions, Next Fiscal Year	$ 1,700

Pension Liability - Net periodi

Pension Liability - Net periodic pension expense (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Pension Liability
Service cost	$ 124		$ 124
Interest cost	274	$ 205	668	$ 637
Expected return on plan assets	(160)	(151)	(496)	(470)
Amortization of actuarial gains and losses	90	64	323	333
Net periodic pension cost	$ 328	$ 118	$ 619	$ 500

Stock-Based Compensation - Narr

Stock-Based Compensation - Narrative (Details) shares in Millions	9 Months Ended
	Sep. 30, 2019shares
2017 OMNIBUS Incentive Plan [Member] [Domain]
Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Reserved	3
Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Available for Grant	2.3
Restricted Stock Units (RSUs) [Member] | Minimum [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Period	3 years
Restricted Stock Units (RSUs) [Member] | Maximum [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Period	4 years
Stock Option Awards [Member]
Share based Compensation Arrangement By Share based Payment Award Options Contractual Term	10 years
Stock Option Awards [Member] | Minimum [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Period	3 years
Stock Option Awards [Member] | Maximum [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Period	4 years

Stock-Based Compensation - Sche

Stock-Based Compensation - Schedule of stock-based compensation (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Stock-Based Compensation
Stock-based compensation expense	$ 917	$ 1,024	$ 5,053	$ 7,461

Stock-Based Compensation - Summ

Stock-Based Compensation - Summary of non-vested Restricted Stock Units activity (Details) - Restricted Stock Units (RSUs) [Member] - $ / shares shares in Thousands	3 Months Ended	9 Months Ended
	Sep. 30, 2019	Sep. 30, 2019	Mar. 31, 2019	Dec. 31, 2018
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Options, Grants in Period, Weighted Average Grant Date Fair Value	$ 57.01	$ 52.18
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Forfeitures, Weighted Average Grant Date Fair Value	$ 58.27	$ 51.74
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number	534	534	553	352
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period	18	377
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Vested in Period, Weighted Average Grant Date Fair Value	$ 27.69	$ 50.90
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Vested in Period	(7)	(153)
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Forfeited in Period	(30)	(42)
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Weighted Average Grant Date Fair Value	$ 56.52	$ 56.52	$ 56.23	$ 58.17

Stock-Based Compensation - Su_2

Stock-Based Compensation - Summary of stock option activity (Details) - Time Based [Member] - $ / shares shares in Thousands	3 Months Ended	9 Months Ended
	Sep. 30, 2019	Sep. 30, 2019	Mar. 31, 2019	Dec. 31, 2018
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Number	191	191	213	230
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Weighted Average Exercise Price	$ 21.37	$ 21.37	$ 21.50	$ 20.73
Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercises in Period	(21)	(37)
Share-based Compensation Arrangements by Share-based Payment Award, Options, Exercises in Period, Weighted Average Exercise Price	$ 22.90	$ 18.03
Share-based Compensation Arrangement by Share-based Payment Award, Options, Expirations in Period	(1)	(2)
Share-based Compensation Arrangement by Share-based Payment Award, Options, Forfeitures and Expirations in Period, Weighted Average Exercise Price	$ 11.21	$ 8.95

Commitments and Contingencies_2

Commitments and Contingencies (Details) $ in Millions	Sep. 30, 2019USD ($)
Commitments and Contingencies
Purchase Commitment, Remaining Minimum Amount Committed	$ 179.7

Related Party Transactions (Det

Related Party Transactions (Details) $ in Thousands	3 Months Ended	9 Months Ended		12 Months Ended
	Sep. 30, 2019USD ($)company	Sep. 30, 2019USD ($)company	Sep. 30, 2018company	Dec. 31, 2018USD ($)company
Related Party Transaction [Line Items]
Number of related party customers	1	1	1
Accounts Receivable, Related Parties | $	$ 41	$ 41		$ 109
Management [Member]
Related Party Transaction [Line Items]
Number of related party customers		1		1

Related Party Transactions - Sc

Related Party Transactions - Schedule of related party transactions (Details) $ in Thousands	3 Months Ended	9 Months Ended
	Sep. 30, 2019USD ($)company	Sep. 30, 2019USD ($)company	Sep. 30, 2018USD ($)company
Related Party Transactions
Sales to related parties | $	$ 287	$ 1,299	$ 389
Number of related party customers | company	1	1	1

Significant Customer Informat_3

Significant Customer Information (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended		12 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018	Dec. 31, 2018
Revenue, Major Customer [Line Items]
Total sales, As Reported	$ 175,127	$ 173,082	$ 450,680	$ 564,731
Product [Member]
Revenue, Major Customer [Line Items]
Total sales, As Reported	$ 148,138	$ 144,843	$ 366,443	$ 485,287
Sales Revenue, Net [Member] | Customer Concentration Risk [Member] | Applied Materials, Inc. [Member]
Revenue, Major Customer [Line Items]
Concentration Risk, Percentage	22.20%	35.00%	24.20%	35.10%
Sales Revenue, Net [Member] | Customer Concentration Risk [Member] | Applied Materials, Inc. [Member] | Product [Member]
Revenue, Major Customer [Line Items]
Total sales, As Reported	$ 38,957	$ 60,546	$ 108,978	$ 198,159
Sales Revenue, Net [Member] | Customer Concentration Risk [Member] | Lam Research [Member]
Revenue, Major Customer [Line Items]
Concentration Risk, Percentage	12.60%	11.50%	13.60%	16.40%
Sales Revenue, Net [Member] | Customer Concentration Risk [Member] | Lam Research [Member] | Product [Member]
Revenue, Major Customer [Line Items]
Total sales, As Reported	$ 21,991	$ 19,878	$ 61,364	$ 92,368
Accounts Receivable [Member] | Customer Concentration Risk [Member] | Applied Materials, Inc. [Member]
Revenue, Major Customer [Line Items]
Concentration Risk, Amount	$ 30,669		$ 30,669		$ 34,301
Concentration Risk, Percentage			12.30%		34.20%
Accounts Receivable [Member] | Customer Concentration Risk [Member] | Lam Research [Member]
Revenue, Major Customer [Line Items]
Concentration Risk, Amount					$ 12,181
Concentration Risk, Percentage					12.10%

Credit Facility (Details)

Credit Facility (Details) $ in Millions	Sep. 30, 2019USD ($)
Revolving Facility [Member]
Line of Credit Facility [Line Items]
Line of credit facility, borrowing capacity	$ 500
Unused line fee payment percentage	0.10%
Credit availability under the Loan Agreement	$ 150
Revolving Facility [Member] | Bank of America N.A. [Member]
Line of Credit Facility [Line Items]
Line of credit facility, current borrowing capacity	150
Term Loan Facility [Member]
Line of Credit Facility [Line Items]
Line of credit facility, borrowing capacity	350
Unsecured Revolving Facility [Member]
Line of Credit Facility [Line Items]
Line of credit facility, borrowing capacity	$ 150
Revolving Credit Facility and Term Loan Facility
Line of Credit Facility [Line Items]
Effective rate percentage	2.79%

Credit Facility - Debt obligati

Credit Facility - Debt obligation (Details) $ in Thousands	Sep. 30, 2019USD ($)
Debt:
Other debt issuance costs	$ (2,356)
Total debt	343,269
Less current portion of debt	(17,500)
Total long-term debt	325,769
Term Loan Facility [Member]
Debt:
Debt	$ 345,625

Credit Facility - Contractual m

Credit Facility - Contractual maturities (Details) $ in Thousands	Sep. 30, 2019USD ($)
Credit Facility
2019 (remaining)	$ 4,375
2020	17,500
2021	17,500
2022	17,500
2023	17,500
2024	$ 271,250

Credit Facility - Interest expe

Credit Facility - Interest expense and unused line of credit fees (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Credit Facility
Interest expense	$ 703		$ 703
Amortization of debt issuance costs	45		45
Unused line of credit fees	60	$ 57	179	$ 171
Total interest expense	$ 808	$ 57	$ 927	$ 171