Advanced Energy Industries (AEIS) 10-K 16 Mar 22 2021 FY Annual report Financial data

Document and Entity Information

Document and Entity Information - USD ($)	12 Months Ended
	Dec. 31, 2021	Mar. 10, 2022	Jun. 30, 2021
Document and Entity Information
Document Type	10-K
Document Annual Report	true
Document Transition Report	false
Document Period End Date	Dec. 31, 2021
Entity File Number	000-26966
Entity Registrant Name	ADVANCED ENERGY INDUSTRIES INC
Entity Incorporation, State or Country Code	DE
Entity Tax Identification Number	84-0846841
Entity Address, Address Line One	1595 Wynkoop Street, Suite 800
Entity Address, City or Town	Denver
Entity Address, State or Province	CO
Entity Address, Postal Zip Code	80202
City Area Code	970
Local Phone Number	407-6626
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
ICFR Auditor Attestation Flag	true
Entity Shell Company	false
Entity Well-known Seasoned Issuer	Yes
Entity Voluntary Filers	No
Entity Public Float			$ 4,280,072,758
Entity Common Stock, Shares Outstanding		37,558,687
Auditor Name	Ernst & Young LLP
Auditor Firm ID	42
Auditor Location	Denver, Colorado
Entity Central Index Key	0000927003
Current Fiscal Year End Date	--12-31
Document Fiscal Year Focus	2021
Document Fiscal Period Focus	FY
Amendment Flag	false

Consolidated Balance Sheets

Consolidated Balance Sheets - USD ($) $ in Thousands	Dec. 31, 2021	Dec. 31, 2020
Current assets:
Cash and cash equivalents	$ 544,372	$ 480,368
Marketable securities	2,296	2,654
Accounts and other receivable, net	237,227	235,178
Inventories	338,410	221,346
Income taxes receivable	10,768	4,804
Other current assets	29,161	35,899
Total current assets	1,162,234	980,249
Property and equipment, net	114,830	114,731
Operating lease right-of-use assets	101,769	103,858
Deposits and other assets	19,669	19,101
Goodwill	212,190	209,983
Intangible assets, net	159,406	168,939
Deferred income tax assets	47,242	50,801
TOTAL ASSETS	1,817,340	1,647,662
Current liabilities:
Accounts payable	193,708	125,224
Income taxes payable	9,226	11,850
Accrued payroll and employee benefits	55,833	63,487
Other accrued expenses	53,445	49,565
Customer deposits and other	22,141	12,179
Current portion of long-term debt	20,000	17,500
Current portion of operating lease liabilities	15,843	16,592
Total current liabilities	370,196	296,397
Long-term debt, net	372,733	304,546
Operating lease liabilities	95,180	95,993
Pension benefits	67,255	80,447
Deferred income tax liabilities	9,921	10,088
Uncertain tax positions	5,940	12,839
Long-term deferred revenue	6,200	7,352
Other long-term liabilities	18,419	24,660
Total liabilities	945,844	832,322
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; 37,589 and 38,293 issued and outstanding at December 31, 2021 and 2020, respectively	38	38
Additional paid-in capital	115,706	105,009
Accumulated other comprehensive loss	(1,216)	(2,605)
Retained earnings	756,323	712,297
Advanced Energy stockholders' equity	870,851	814,739
Noncontrolling interest	645	601
Total stockholders' equity	871,496	815,340
TOTAL LIABILITIES AND STOCKHOLDERS' EQUITY	$ 1,817,340	$ 1,647,662

Consolidated Balance Sheets (Pa

Consolidated Balance Sheets (Parenthetical) - $ / shares shares in Thousands	Dec. 31, 2021	Dec. 31, 2020
Consolidated Balance Sheets
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 (in shares)	0	0
Common stock, par value (in dollars per share)	$ 0.001	$ 0.001
Common stock, shares authorized (in shares)	70,000	70,000
Common stock, shares issued (in shares)	37,589	38,293
Common stock, shares outstanding (in shares)	37,589	38,293

Consolidated Statements of Oper

Consolidated Statements of Operations - USD ($) shares in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Consolidated Statements of Operations
Sales, net	$ 1,455,954	$ 1,415,826	$ 788,948
Cost of sales	923,632	873,957	473,296
Gross profit	532,322	541,869	315,652
Operating expenses:
Research and development	161,831	143,961	101,503
Selling, general, and administrative	191,998	188,590	142,555
Amortization of intangible assets	22,060	20,129	12,168
Restructuring expense	4,752	13,166	5,038
Total operating expenses	380,641	365,846	261,264
Operating income	151,681	176,023	54,388
Other income (expense), net	(2,970)	(17,876)	12,806
Income from continuing operations, before income taxes	148,711	158,147	67,194
Provision for income taxes	14,004	22,996	10,699
Income from continuing operations	134,707	135,151	56,495
Income (loss) from discontinued operations, net of income taxes	73	(421)	8,480
Net income	134,780	134,730	64,975
Less: income from continuing operations attributable to noncontrolling interest	44	55	34
Net income attributable to Advanced Energy Industries, Inc.	$ 134,736	$ 134,675	$ 64,941
Basic weighted-average common shares outstanding	38,143	38,314	38,281
Diluted weighted-average common shares outstanding	38,355	38,542	38,495
Earnings per share:
Continuing operations: Basic earnings per share	$ 3.53	$ 3.53	$ 1.47
Continuing operations: Diluted earnings per share	3.51	3.51	1.47
Discontinued operations: Basic earnings (loss) per share		(0.01)	0.22
Discontinued operations: Diluted earnings (loss) per share		(0.01)	0.22
Net income:
Basic earnings per share	3.53	3.52	1.70
Diluted earnings per share	$ 3.51	$ 3.50	$ 1.69

Consolidated Statements of Comp

Consolidated Statements of Comprehensive Income - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Consolidated Statements of Comprehensive Income
Net income	$ 134,780	$ 134,730	$ 64,975
Other comprehensive income (loss), net of income taxes
Foreign currency translation	(12,262)	13,095	(2,523)
Change in fair value of cash flow hedges	4,246	(2,139)
Minimum benefit retirement liability	9,405	(7,664)	75
Comprehensive income	136,169	138,022	62,527
Comprehensive income attributable to noncontrolling interest	44	55	34
Comprehensive income attributable to Advanced Energy Industries, Inc.	$ 136,125	$ 137,967	$ 62,493

Consolidated Statements of Stoc

Consolidated Statements of Stockholders' Equity - USD ($) shares in Thousands, $ in Thousands	Common Stock	Additional Paid-in Capital	Accumulated Other Comprehensive Income	Retained EarningsCumulative Effect, Period of Adoption, Adjustment [Member]	Retained Earnings	Non-controlling Interest	Cumulative Effect, Period of Adoption, Adjustment [Member]	Total
Beginning Balance at Dec. 31, 2018	$ 38	$ 97,418	$ (3,449)		$ 512,783	$ 512		$ 607,302
Beginning Balance (in shares) at Dec. 31, 2018	38,164
Stock issued from equity plans		104						104
Stock issued from equity plans (in shares)	194
Stock-based compensation		7,327						7,327
Other comprehensive income (loss)			(2,448)					(2,448)
Net income					64,941	34		64,975
Ending Balance at Dec. 31, 2019	$ 38	104,849	(5,897)	$ (102)	577,724	546	$ (102)	677,260
Ending Balance (in shares) at Dec. 31, 2019	38,358
Stock issued from equity plans		(482)						(482)
Stock issued from equity plans (in shares)	179
Stock-based compensation		12,272						12,272
Share repurchase		(11,630)						(11,630)
Share repurchase (in shares)	(244)
Other comprehensive income (loss)			3,292					3,292
Net income					134,675	55		134,730
Ending Balance at Dec. 31, 2020	$ 38	105,009	(2,605)		712,297	601		$ 815,340
Ending Balance (in shares) at Dec. 31, 2020	38,293							38,293
Stock issued from equity plans		(1,931)						$ (1,931)
Stock issued from equity plans (in shares)	197
Stock-based compensation		15,428						15,428
Share repurchase		(2,800)			(75,325)			(78,125)
Share repurchase (in shares)	(901)
Dividends declared					(15,385)			(15,385)
Other comprehensive income (loss)			1,389					1,389
Net income					134,736	44		134,780
Ending Balance at Dec. 31, 2021	$ 38	$ 115,706	$ (1,216)		$ 756,323	$ 645		$ 871,496
Ending Balance (in shares) at Dec. 31, 2021	37,589							37,589

Consolidated Statements of St_2

Consolidated Statements of Stockholders' Equity (Parenthetical)	12 Months Ended
	Dec. 31, 2021$ / shares
Consolidated Statements of Stockholders' Equity
Dividends declared (in dollars per share)	$ 0.10

Consolidated Statements of Cash

Consolidated Statements of Cash Flows - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
CASH FLOWS FROM OPERATING ACTIVITIES:
Net income	$ 134,780	$ 134,730	$ 64,975
Less: income (loss) from discontinued operations, net of income taxes	73	(421)	8,480
Income from continuing operations, net of income taxes	134,707	135,151	56,495
Adjustments to reconcile net income to net cash from operating activities:
Depreciation and amortization	52,893	47,770	26,147
Stock-based compensation expense	15,739	12,272	7,327
Provision for deferred income taxes	1,326	(622)	1,015
(Gain) loss from discount on notes receivable	(638)	721	1,100
Gain on sale of central inverter service business			(14,795)
Loss on disposal of assets	1,496	1,296	700
Changes in operating assets and liabilities, net of assets acquired:
Accounts and other receivable, net	5,271	15,412	(18,879)
Inventories	(115,737)	11,658	3,687
Other assets	(2,910)	1,750	23,544
Accounts payable	67,111	(48,163)	(16,094)
Other liabilities and accrued expenses	(4,414)	24,520	(12,486)
Income taxes	(13,930)	394	(9,862)
Net cash from operating activities from continuing operations	140,914	202,159	47,899
Net cash from operating activities from discontinued operations	(669)	(923)	493
Net cash from operating activities	140,245	201,236	48,392
CASH FLOWS FROM INVESTING ACTIVITIES:
Net proceeds from sale of marketable securities		3	1,742
Receipt (issuance) of notes receivable	3,050	(1,000)	(4,300)
Proceeds from sale of assets	3,060	116
Purchases of property and equipment	(31,877)	(36,483)	(25,188)
Acquisitions, net of cash acquired	(21,535)	(5,476)	(366,101)
Net cash from investing activities	(47,302)	(42,840)	(393,847)
CASH FLOWS FROM FINANCING ACTIVITIES:
Proceeds from long-term borrowings	85,000		347,486
Payment of debt-issuance costs	(1,350)
Payments on long-term borrowings	(13,750)	(17,500)	(8,750)
Dividend payments	(15,385)
Purchase and retirement of common stock	(78,125)	(11,630)
Net payments related to stock-based awards	(1,762)	(482)	104
Net cash from financing activities	(25,372)	(29,612)	338,840
EFFECT OF CURRENCY TRANSLATION ON CASH AND CASH EQUIVALENTS	(3,567)	5,143	(1,496)
NET CHANGE IN CASH AND CASH EQUIVALENTS	64,004	133,927	(8,111)
CASH AND CASH EQUIVALENTS, beginning of period	480,368	346,441	354,552
CASH AND CASH EQUIVALENTS, end of period	544,372	480,368	346,441
SUPPLEMENTAL DISCLOSURE OF CASH FLOW INFORMATION:
Cash paid for interest	4,040	5,278	3,479
Cash paid for income taxes	32,543	21,032	18,594
Cash received for refunds of income taxes	$ 12,506	$ 1,569	$ 1,762

OPERATIONS AND SUMMARY OF SIGNI

OPERATIONS AND SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES AND ESTIMATES	12 Months Ended
	Dec. 31, 2021
OPERATIONS AND SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES AND ESTIMATES
OPERATIONS AND SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES AND ESTIMATES	NOTE 1. OPERATIONS AND SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES AND ESTIMATES 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 coming from either the utility or the building facility and convert it into various types of highly controllable, usable power that is predictable, repeatable, and customizable to meet the necessary requirements for powering a wide range of complex equipment. Our power solutions enable innovation in complex semiconductor and thin film plasma processes such as dry etch, strip and deposition, high and low voltage applications such as semiconductor process control, data center computing, networking, telecommunication, medical equipment, life science applications, industrial technology and production, scientific instruments, clean technology production, advanced material production and temperature-critical thermal applications. We also supply related sensing, controls, and instrumentation products for advanced measurement and calibration of radio frequency (“RF”) power and temperature, and electrostatic instrumentation products for test and measurement applications. Our network of global service support centers provides a recurring revenue opportunity as we offer repair services, conversions, upgrades, refurbishments, and used equipment to companies using our products. In September 2019, we acquired the Artesyn Embedded Power business ("Artesyn") Note 4. Disposed and Discontinued Operations Principles of Consolidation Use of Estimates in the Preparation of the Consolidated Financial Statements — ● excess and obsolete inventory; ● pension obligations; ● acquisitions and asset valuations, and ● taxes and other provisions. ​ Foreign Currency Translation — For certain other subsidiaries, the functional currency is the U.S. Dollar. Foreign currency transactions are recorded based on exchange rates at the time such transactions arise. Subsequent changes in exchange rates for foreign currency denominated monetary assets and liabilities result in foreign currency transaction gains and losses, which are reflected as unrealized (based on period end remeasurement) or realized (upon settlement of the transactions) in Other income (expense), net in our Consolidated Statements of Operations. Derivatives — We use derivative financial instruments to manage risks associated with foreign currency and interest rate fluctuations. Unless we meet specific hedge accounting criteria, changes in the fair value of derivative financial instruments are recognized in the Consolidated Statements of Operations within Other income (expense), net. For derivatives designated as cash flow hedges, changes in fair value are recorded to Accumulated other comprehensive loss on the Consolidated Balance Sheets and are reclassified to earnings when the underlying forecasted transaction affects earnings. We reassess the probability of the underlying forecasted transactions occurring on a quarterly basis. Fair Value — U.S. GAAP for fair value establishes a hierarchy that prioritizes fair value measurements based on the types of inputs used for the various valuation techniques (market approach, income approach, and cost approach). Our financial assets and liabilities are measured using inputs from the three levels of the fair value hierarchy. The three levels of the hierarchy and the related inputs are as follows: ● Level 1 — Quoted prices (unadjusted) in active markets for identical assets or liabilities that the entity can access on the measurement date. ● Level 2 — Inputs other than quoted prices included within Level 1 that are observable for the asset or liability, either directly or indirectly. ● Level 3 — Unobservable inputs for the asset or liability. We categorize fair value measurements within the fair value hierarchy based upon the lowest level of the most significant inputs used to determine fair value. Our assessment of the significance of a particular input to the fair value measurement requires judgment and may affect the valuation of the fair value of assets and liabilities and their placement within the fair value hierarchy levels. The carrying amounts of our cash and cash equivalents, accounts receivable, accounts payable and other current assets and liabilities approximate fair value as recorded due to the short-term nature of these instruments. Our non-financial assets, which primarily consist of property and equipment, goodwill, and other intangible assets, are not required to be carried at fair value on a recurring basis and are reported at carrying value. However, on a periodic basis or whenever events or changes in circumstances indicate that their carrying value may not be fully recoverable (and at least annually for goodwill), non-financial instruments are assessed for impairment and, if applicable, written down to and recorded at fair value. See Note 12. Goodwill Note 13. Intangible Assets The fair value of borrowings approximates the recorded borrowing value based upon market interest rates for similar facilities. See Note 21. Credit Facility Cash, Cash Equivalents, and Marketable Securities In some instances, we invest excess cash in money market funds not insured by the Federal Deposit Insurance Corporation. We believe the investments in money market funds are on deposit with credit-worthy financial institutions and the funds are highly liquid. These investments are reported at fair value and included in Cash and cash equivalents. We record interest income within Other income (expense), net in our Consolidated Statement of Operations. We classify investments with stated maturities of greater than three months at time of purchase as marketable securities. Concentrations of Credit Risk — We establish a reserve for credit losses based upon factors surrounding the credit risk of specific customers, historical trends, and other information. Accounts Receivable and Reserve for Credit Losses — Inventories Property and Equipment When depreciable assets are retired, or otherwise disposed of, the cost and related accumulated depreciation are removed from the accounts, and any related gains or losses are included in Other income (expense), net, in our Consolidated Statements of Operations. Purchase accounting Leases Right-of-use assets and operating lease liabilities are recognized at the present value of the future lease payments on the lease commencement date. The interest rate used to determine the present value of the future lease payments is our incremental borrowing rate because the interest rate implicit in our leases is not readily determinable. Our incremental borrowing rate is estimated to approximate the interest rate on a collateralized basis with similar terms and payments. We have a centrally managed treasury function; therefore, we apply a portfolio approach for determining the incremental borrowing rate applicable to the lease term. Operating lease expense is recognized on a straight-line basis over the lease term. Intangible Assets, Goodwill, and Other Long-Lived Assets The estimation of useful lives and expected cash flows requires us to make judgments regarding future periods that are subject to some factors outside of our control. Changes in these estimates can result in revisions to our carrying value of these assets and may result in material charges to our results of operations. We conduct an annual goodwill impairment analysis using an assessment of qualitative factors in determining if it is more likely than not that goodwill is impaired. If this assessment indicates that it is more likely than not that goodwill is impaired, the next step of impairment testing compares the fair value of a reporting unit to its carrying value. Goodwill would be impaired if the resulting implied fair value of goodwill was less than the recorded carrying value of the goodwill. Debt Issuance Costs Amortization of debt issuance costs is reflected in Other income (expense), net on the Consolidated Statements of Operations. See Note 21. Credit Facility Revenue Recognition We maintain a worldwide support organization in ten countries, including the U.S., the People's Republic of China ("PRC"), Japan, Korea, Taiwan, Germany, Ireland, Singapore, Israel, and Great Britain. 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. Research and Development Expenses Warranty Costs five Note 4. Disposed and Discontinued Operations Note 15. Warranties Stock-Based Compensation We estimate the fair value of restricted stock units ("RSUs") on the grant date. For RSUs that contain a time-based and/or performance-based vesting condition, we estimate fair value using the closing share price on the grant date. We record stock-based compensation expense for awards with time-based vesting conditions over the term of the award. For awards with a performance-based vesting condition, we record stock-based compensation expense (based on management's assessment of the probability of meeting the performance conditions) over the estimated period to achieve the performance conditions. Upon forfeiture or expiration of these awards, we reverse the stock-based compensation expense. Certain RSUs vest based on a market condition. We estimate the fair value and probability of achievement for each tranche of these awards using a Monte Carlo simulation. Because the probability of achievement is a factor in the Monte Carlo simulation, we recognize stock-based compensation expense over each tranche’s estimated achievement period even if some or all of the shares never vest. We estimate the fair value of the purchase rights in our employee stock purchase plan using a Black-Scholes Merton option pricing model and recognize compensation expense over the term of the purchase right. For all stock awards, we estimate forfeitures at the grant date and revise those estimates in subsequent periods if actual forfeitures differ from our estimates. Income Taxes We assess the recoverability of our net deferred tax assets and the need for a valuation allowance on a quarterly basis. Our assessment includes several factors including historical results and taxable income projections for each jurisdiction. The ultimate realization of deferred income tax assets is dependent on the generation of taxable income in appropriate jurisdictions during the periods in which those temporary differences are deductible. We consider the scheduled reversal of deferred income tax liabilities, projected future taxable income, and tax planning strategies in determining the amount of the valuation allowance. Based on the level of historical taxable income and projections for future taxable income over the periods in which the deferred income tax assets are deductible, we determine if we will realize the benefits of these deductible differences. Accounting for income taxes requires a two-step approach to recognize and measure uncertain tax positions. In general, we are subject to regular examination of our income tax returns by the Internal Revenue Service and other tax authorities. The first step is to evaluate the tax position for recognition by determining, if based on the technical merits, it is more likely than not that the position will be sustained upon audit, including resolutions of related appeals or litigation processes, if any. The second step is to measure the tax benefit as the largest amount that is more than 50% likely of being realized upon ultimate settlement. We regularly assess the likelihood of favorable or unfavorable outcomes resulting from these examinations to determine the adequacy of our provision for income taxes. This evaluation is based on factors including, but not limited to, changes in facts or circumstances, changes in tax law, effectively settled issues under audit, and new audit activity. Under U.S. GAAP, an accounting policy election can be made to either recognize deferred taxes for temporary basis differences expected to reverse as global intangible low-tax income ("GILTI") in future years, or to provide for the tax expense related to GILTI in the year the tax is incurred as a period expense only. We have elected to account for GILTI in the year the tax is incurred. Commitments and Contingencies NEW ACCOUNTING STANDARDS 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, will not have a material impact on the consolidated financial statements upon adoption. New Accounting Standards Adopted 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 was effective for us on January 1, 2021. The impact of adoption was not material to our consolidated financial statements. New Accounting Standards In March 2020, the FASB issued ASU 2020-04, "Reference Rate Reform (Topic 848): Facilitation of the Effects of Reference Rate Reform on Financial Reporting" "Reference Rate Reform (Topic 848): Scope" ​ Our Credit Facility (refer to Note 21. Credit Facility Note 8. Derivative Financial Instruments Note 21. Credit Facility In October 2021, the FASB issued ASU 2021-08, " Business Combinations (Topic 806) Accounting for Contract Assets and Contract Liabilities from Contracts with Customers." will improve the accounting for acquired revenue contracts with customers in a business combination. This pronouncement will be effective for us on January 1, 2023. We are still evaluating the impact, if any, that the adoption of ASU 2021-08 may have on our consolidated financial statements.

ACQUISITIONS

ACQUISITIONS	12 Months Ended
	Dec. 31, 2021
ACQUISITIONS
ACQUISITIONS	NOTE 2. ACQUISITIONS Intangible Assets Acquired In January 2021, we acquired certain intangible assets related to the manufacturing of fiber optic sensing equipment. As of December 31, 2021, we paid $6.1 million in cash and expect to pay an additional $0.4 million within one year of the closing. These intangible assets have an estimated useful life of five years. See Note 13. Intangible Assets TEGAM, Inc. On June 1, 2021, we acquired 100% of the issued and outstanding shares of capital stock of TEGAM, Inc., which is based in Geneva, Ohio. This acquisition added metrology and calibration instrumentation to Advanced Energy’s RF process power solutions in our Semiconductor and Industrial and Medical markets. The components of the fair value of the total consideration transferred were as follows: ​ ​ ​ ​ ​ Cash paid for acquisition $ 15,430 Holdback ​ ​ 1,800 Total fair value of consideration transferred ​ ​ 17,230 Less cash acquired ​ ​ (177) Total purchase price ​ $ 17,053 ​ The following table summarizes the preliminary values of the assets acquired and liabilities assumed: ​ ​ ​ ​ ​ ​ Preliminary Fair Value Current assets and liabilities, net ​ $ 3,536 Property and equipment ​ ​ 734 Operating lease right-of-use assets ​ ​ 425 Intangible assets ​ ​ 6,900 Goodwill (deductible for tax purposes) ​ ​ 5,877 Other non-current assets ​ ​ 31 Total assets acquired ​ ​ 17,503 Other non-current liabilities ​ ​ 25 Operating lease liability ​ ​ 425 Total liabilities assumed ​ ​ 450 Total fair value of net assets acquired ​ $ 17,053 ​ A summary of the intangible assets acquired, amortization method, and estimated useful lives follows: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Amortization ​ ​ ​ ​ Method Useful Life Technology ​ $ 1,100 Straight-line 5 Customer relationships ​ 5,500 Straight-line 15 Tradename ​ 300 Straight-line 5 Total ​ $ 6,900 ​ Versatile Power, Inc On December 31, 2020, we acquired 100% of the issued and outstanding shares of Versatile Power, Inc., which is based in Campbell, California. This acquisition added radio frequency ("RF") and programmable power supplies for medical and industrial applications to our product portfolio and further expands our presence in the medical market by adding proven technologies, deep customer relationships, expertise in medical design, and a medical-certified manufacturing center. The components of the fair value of the total consideration transferred were as follows: ​ ​ ​ ​ ​ Cash paid for acquisition $ 4,654 Holdback ​ ​ 950 Total fair value of consideration transferred ​ ​ 5,604 Less cash acquired ​ ​ (245) Total purchase price ​ $ 5,359 ​ The following table summarizes the final values of the assets acquired and liabilities assumed: ​ ​ ​ ​ ​ ​ Fair Value Current assets and liabilities, net ​ $ 1,021 Property and equipment ​ ​ 35 Operating lease right-of-use assets ​ ​ 463 Intangible assets ​ ​ 4,000 Goodwill (deductible for tax purposes) ​ ​ 323 Total assets acquired ​ ​ 5,842 Other non-current liabilities ​ ​ 20 Operating lease liability ​ ​ 463 Total liabilities assumed ​ ​ 483 Total fair value of net assets acquired ​ $ 5,359 ​ A summary of the intangible assets acquired, amortization method, and estimated useful lives follows: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Amortization ​ ​ ​ ​ ​ ​ Method ​ Useful Life Technology ​ $ 400 Straight-line 5 Customer relationships ​ 3,600 Straight-line 15 Total ​ $ 4,000 ​ ​

REVENUE

REVENUE	12 Months Ended
	Dec. 31, 2021
REVENUE
REVENUE	NOTE 3. REVENUE 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, refine, and modify the raw electrical power coming from either the utility or the building facility and convert it into various types of highly controllable, usable power that is predictable, repeatable, and customizable to meet the necessary requirements for powering a wide range of complex equipment. Our power solutions enable innovation in complex semiconductor and thin film plasma processes such as dry etch, strip and deposition, high and low voltage applications such as process control, data center computing, networking, telecommunication, medical equipment, life science applications, industrial technology and production, scientific instruments, clean technology production, advanced material production and temperature-critical thermal applications such as material and chemical processing. We also supply related sensing, controls, and instrumentation products for advanced measurement and calibration of radio RF power and temperature, electrostatic instrumentation products for test and measurement applications, and gas sensing and monitoring solutions for multiple industrial markets. Our network of global service support centers provides a recurring revenue opportunity as we offer repair services, conversions, upgrades, refurbishments, and used equipment to companies using our products. 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 in the U.S., the PRC, Japan, Korea, Taiwan, Germany, Ireland, Singapore, Israel, and Great Britain. Support services include warranty and non-warranty repair services, upgrades, and refurbishments on the products we sell. 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. The following table summarizes deferred revenue, which relates to extended warranties and service contracts. We expect to recognize this revenue ratably through the year 2031. ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, ​ December 31, ​ 2021 2020 Deferred revenue ​ $ 7,067 ​ $ 8,671 ​ Disaggregation of Revenue The following tables present additional information regarding our revenue: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Years Ended December 31, ​ ​ ​ 2021 2020 2019 Semiconductor Equipment ​ ​ $ 710,174 ​ $ 611,864 ​ $ 403,018 Industrial and Medical ​ ​ 341,176 ​ 313,646 ​ 245,992 Data Center Computing ​ ​ ​ 270,924 ​ ​ 322,539 ​ ​ 91,438 Telecom and Networking ​ ​ ​ 133,680 ​ ​ 167,777 ​ ​ 48,500 Total ​ ​ $ 1,455,954 ​ $ 1,415,826 ​ $ 788,948 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Years Ended December 31, ​ 2021 2020 2019 United States ​ ​ $ 561,312 ​ 38.5 % $ 530,965 ​ 37.5 % $ 321,869 ​ 40.8 % North America (excluding U.S.) ​ ​ ​ 104,167 7.2 ​ ​ 156,856 11.1 ​ ​ 51,765 6.6 ​ Asia ​ ​ 597,830 41.1 ​ 606,893 42.9 ​ 295,155 37.4 ​ Europe ​ ​ 179,056 12.3 ​ 117,989 8.3 ​ 119,427 15.1 ​ Other ​ ​ 13,589 0.9 ​ 3,123 0.2 ​ 732 0.1 ​ Total ​ ​ $ 1,455,954 100.0 % $ 1,415,826 100.0 % $ 788,948 100.0 % ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Years Ended December 31, ​ 2021 2020 2019 Product ​ $ 1,318,213 ​ $ 1,296,867 ​ $ 678,061 Services ​ ​ 137,741 ​ 118,959 ​ 110,887 Total ​ $ 1,455,954 $ 1,415,826 $ 788,948 ​

DISPOSED AND DISCONTINUED OPERA

DISPOSED AND DISCONTINUED OPERATIONS	12 Months Ended
	Dec. 31, 2021
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 ("Bold") for $1.00 dollar and Bold's assumption of certain product warranty obligations. In connection with this transaction, we entered into a Loan and Security Agreement whereby we loaned Bold an aggregate $5.3 million between May 2019 and the first quarter of 2020. During the year ended December 31, 2021, Bold repaid the amount borrowed at a discounted amount in accordance with the terms of the agreement. The loan is now fully repaid, and the Loan and Security Agreement has been cancelled. As a result of the transaction, during the year ended December 31, 2019, we reduced our discontinued operations liabilities by approximately $10.9 million that were related to initial product warranty and reduced our other liabilities by approximately $22.0 million that were related to extended warranty service obligations as well as reduced other assets and liabilities associated with the continuing grid-tied central solar inverter service and repair business. Accordingly, we recognized a $14.8 million non-cash gain in Other income (expense) from continuing operations and an $8.6 million non-cash gain, net of tax expense of $2.4 million, in Income (loss) from discontinued operations. Discontinued Operations In December 2015, we completed the wind down of engineering, manufacturing, and sales of our solar inverter product line. Accordingly, the results of our inverter business are reflected as Income (loss) from discontinued operations, net of income taxes on our Consolidated Statements of Operations. 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. We no longer offer extended warranties related to the inverter product line.

INCOME TAXES

INCOME TAXES	12 Months Ended
	Dec. 31, 2021
INCOME TAXES
INCOME TAXES	NOTE 5. INCOME TAXES The geographic distribution of pretax income from continuing operations was as follows: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Years Ended December 31, ​ 2021 2020 2019 Domestic ​ $ 24,541 ​ $ 17,526 ​ $ (20,597) Foreign ​ 124,170 ​ 140,621 ​ 87,791 ​ ​ $ 148,711 ​ $ 158,147 ​ $ 67,194 ​ The provision for income taxes from continuing operations is summarized as follows: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Years Ended December 31, ​ 2021 2020 2019 Current: ​ ​ ​ Federal ​ $ (2,468) ​ $ 5,475 ​ $ (9,627) State ​ 929 ​ 1,927 ​ 882 Foreign ​ 14,217 ​ 16,216 ​ 18,429 Total current provision ​ ​ 12,678 ​ ​ 23,618 ​ ​ 9,684 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Deferred: ​ ​ ​ Federal ​ ​ 762 ​ ​ (312) ​ ​ 3,822 State ​ (200) ​ 1,270 ​ (178) Foreign ​ 764 ​ (1,580) ​ (2,629) Total deferred provision (benefit) ​ 1,326 ​ (622) ​ 1,015 Total provision for income taxes ​ $ 14,004 ​ $ 22,996 ​ $ 10,699 ​ Our effective tax rates differ from the U.S. federal statutory rate of 21% for the years ended December 31, 2021, 2020, and 2019 primarily due to the benefit of earnings in foreign jurisdictions which are subject to lower tax rates as well as reductions in uncertain tax positions and tax credits, offset by net U.S. tax on foreign operations, withholding taxes, and audit settlements. ​ The principal causes of the difference between the federal statutory rate and the effective income tax rate for each of the years below are as follows: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Years Ended December 31, ​ 2021 2020 2019 Income taxes per federal statutory rate ​ $ 31,229 ​ $ 33,211 ​ $ 14,111 State income taxes, net of federal deduction ​ ​ 534 ​ ​ 2,793 ​ ​ 10 U.S. tax on foreign operations ​ ​ 5,786 ​ ​ 9,666 ​ ​ 5,805 Foreign derived intangible income deduction ​ ​ (3,927) ​ ​ (4,070) ​ ​ — Tax effect of foreign operations ​ ​ (11,520) ​ ​ (20,527) ​ ​ (13,086) Uncertain tax positions ​ ​ (6,899) ​ ​ (3,215) ​ ​ (4,487) Audit settlements ​ ​ 7,764 ​ ​ — ​ ​ — Unremitted earnings ​ ​ 261 ​ ​ (567) ​ ​ 1,624 Tax credits ​ ​ (6,149) ​ ​ (2,292) ​ ​ (2,088) Change in valuation allowance ​ ​ (73) ​ ​ (1,175) ​ ​ 7,222 Withholding taxes ​ ​ 756 ​ ​ 4,265 ​ ​ 6,500 Executive compensation limitation ​ ​ 1,926 ​ ​ 1,070 ​ ​ 356 Other permanent items, net ​ ​ (5,684) ​ ​ 3,837 ​ ​ (5,268) Total provision for income taxes ​ $ 14,004 ​ $ 22,996 ​ $ 10,699 ​ Deferred tax assets and liabilities are recognized for the future tax consequences of differences between the carrying amounts of assets and liabilities and their respective tax bases using enacted tax rates in effect for the year in which the differences are expected to be reversed. Significant deferred tax assets and liabilities consist of the following: ​ ​ ​ ​ ​ ​ ​ ​ ​ Years Ended December 31, ​ 2021 2020 Deferred tax assets ​ ​ Stock-based compensation ​ $ 2,528 ​ $ 2,130 Net operating loss and tax credit carryforwards ​ 54,210 ​ 57,590 Interest expense limitation ​ ​ 7,344 ​ ​ 7,344 Pension obligation ​ 10,778 ​ 14,297 Excess and obsolete inventory ​ 3,325 ​ 3,722 Accrued restructuring ​ ​ 2,223 ​ ​ 2,468 Deferred revenue ​ 4,195 ​ 3,048 Employee bonuses and commissions ​ 3,861 ​ 5,388 Amortization ​ 26,358 ​ 28,786 Operating lease liabilities ​ ​ 19,405 ​ ​ 20,267 Other ​ 8,017 ​ 8,925 Deferred tax assets ​ 142,244 ​ 153,965 Less: Valuation allowance ​ (42,051) ​ (46,702) Net deferred tax assets ​ 100,193 ​ 107,263 ​ ​ ​ ​ ​ ​ ​ Deferred tax liabilities ​ ​ ​ Depreciation and amortization ​ 37,515 ​ 40,266 Unremitted earnings ​ 4,435 ​ 4,173 Operating lease right-of-use assets ​ ​ 17,558 ​ ​ 18,731 Other ​ 3,364 ​ 3,380 Deferred tax liabilities ​ 62,872 ​ 66,550 Net deferred tax assets ​ $ 37,321 ​ $ 40,713 ​ Of the $37.3 million and $40.7 million net deferred tax asset on December 31, 2021 and 2020, respectively, $47.2 million and $50.8 million is reflected as a net non-current deferred tax asset and $9.9 million and $10.1 million is reflected as a long-term liability on December 31, 2021 and 2020, respectively. As of December 31, 2021, we have recorded a valuation allowance on $4.0 million of our U.S. domestic deferred tax assets, largely attributable to state carryforward attributes that are expected to expire before sufficient income can be realized in those jurisdictions. The remaining valuation allowance on deferred tax assets approximates $38.0 million and is associated primarily with operations in Germany, Hong Kong, and Switzerland. As of December 31, 2021, there is not sufficient positive evidence to conclude that such deferred tax assets, presently reduced by a valuation allowance, will be recognized. The December 31, 2021 valuation allowance balance reflects a decrease of $4.7 million during the year. The change in the valuation allowance is primarily due to decreases from foreign exchange movements and current year activity. As of December 31, 2021, we had U.S., foreign and state tax loss carryforwards of $56.9 million, $129.0 million, and $117.1 million, respectively. Additionally, we had $0.8 million and $30.5 million of capital loss and interest expense limitation carryforwards, respectively. Finally, we had U.S. and state tax credit carryforwards of $1.5 million and $1.7 million, respectively. The U.S. and state net operating losses, tax credits, and interest expense limitation are subject to various utilization limitations under Section 382 of the Internal Revenue Code and applicable state laws. These Section 382 limited attributes have various expiration periods through 2036 or, in the case of the interest expense limitation amount, no expiration period. Much of the foreign jurisdiction, and $8.0 million of the federal net operating loss carry forwards, have no expiration period. We operate under a tax holiday in Singapore and China. These tax holidays are in effect through June 30, 2027 and December 31, 2022, respectively. The tax holiday is conditional upon our meeting certain employment and investment thresholds. The impact of the tax holidays decreased foreign taxes by $13.3 million and $13.0 million for 2021 and 2020, respectively. The benefit of the tax holiday on earnings per diluted share was $0.35 and $0.34 for 2021 and 2020, respectively. As of December 31, 2021, we have undistributed earnings of certain foreign subsidiaries of approximately $32.4 million that we have indefinitely invested, and on which we have not recognized deferred taxes. Estimating the amount of potential tax is not practicable because of the complexity and variety of assumptions necessary to compute the tax. We account for uncertain tax positions by applying a minimum recognition threshold to tax positions before recognizing these positions in the financial statements. The reconciliation of our total gross unrecognized tax benefits is as follows: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Years Ended December 31, ​ 2021 2020 2019 Balance at beginning of period ​ $ 9,673 ​ $ 13,009 ​ $ 13,162 Additions based on tax positions taken during a prior period ​ 963 ​ 219 ​ 484 Additions based on tax positions taken during a prior period - acquisitions ​ — ​ — ​ 4,479 Additions based on tax positions taken during the current period ​ 566 ​ — ​ — Reductions based on tax positions taken during a prior period ​ — ​ — ​ (4,295) Reductions related to a lapse of applicable statute of limitations ​ (4,575) ​ (3,555) ​ (821) Reductions related to a settlement with taxing authorities ​ (1,114) ​ — ​ — Balance at end of period ​ $ 5,513 ​ $ 9,673 ​ $ 13,009 ​ The unrecognized tax benefits of $5.5 million, if recognized, will impact our effective tax rate. In accordance with our accounting policy, we recognize accrued interest and penalties related to unrecognized tax benefits as a component of tax expense. We had $0.4 million and $3.2 million of accrued interest and penalties on December 31, 2021 and 2020, respectively. With few exceptions, we are no longer subject to federal, state, or foreign income tax examinations by tax authorities for years before 2018.

EARNINGS PER SHARE

EARNINGS PER SHARE	12 Months Ended
	Dec. 31, 2021
EARNINGS PER SHARE
EARNINGS PER SHARE	NOTE 6. EARNINGS PER SHARE We compute basic earnings per share ("EPS") by dividing income available to common stockholders by the weighted-average number of common shares outstanding during the period. The diluted EPS computation is similar to basic EPS except we increase the denominator 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 (when such conversion is dilutive). The following is a reconciliation of the weighted-average shares outstanding used in the calculation of basic and diluted earnings per share: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Years Ended December 31, ​ 2021 2020 2019 Income from continuing operations $ 134,707 ​ $ 135,151 ​ $ 56,495 Less: income from continuing operations attributable to noncontrolling interest 44 ​ 55 ​ 34 Income from continuing operations attributable to Advanced Energy Industries, Inc. $ 134,663 ​ $ 135,096 ​ $ 56,461 ​ ​ ​ ​ ​ ​ ​ ​ ​ Basic weighted-average common shares outstanding 38,143 ​ 38,314 ​ 38,281 Assumed exercise of dilutive stock options and restricted stock units 212 ​ 228 ​ 214 Diluted weighted-average common shares outstanding 38,355 ​ 38,542 ​ 38,495 ​ ​ ​ ​ ​ ​ ​ ​ ​ Continuing operations: ​ ​ Basic earnings per share $ 3.53 ​ $ 3.53 ​ $ 1.47 Diluted earnings per share $ 3.51 ​ $ 3.51 ​ $ 1.47 ​ Share Repurchase To execute the repurchase of shares of our common stock, we periodically enter into stock repurchase agreements. The following table summarizes these repurchases: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Years Ended December 31, (in thousands, except per share amounts) 2021 2020 Amount paid to repurchase shares ​ $ 78,125 ​ $ 11,630 Number of shares repurchased ​ 901 ​ 244 Average repurchase price per share ​ $ 86.76 ​ $ 47.75 Remaining authorized by Board of Directors for future repurchases as of period end ​ $ 128,377 ​ $ 38,369 ​ There were no shares repurchased from related parties. Repurchased shares were retired and assumed the status of authorized and unissued shares. On July 29, 2021, the Board of Directors approved an increase to the share repurchase program, which authorized the Company to repurchase up to $200 million in shares of our common stock with no time limitation.

FAIR VALUE MEASUREMENTS

FAIR VALUE MEASUREMENTS	12 Months Ended
	Dec. 31, 2021
FAIR VALUE MEASUREMENTS
FAIR VALUE MEASUREMENTS	NOTE 7. FAIR VALUE MEASUREMENTS The following tables present information about our assets and liabilities measured at fair value on a recurring basis. ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, 2021 Description ​ Balance Sheet Classification ​ Level 1 ​ Level 2 ​ Level 3 ​ Total Fair Value Assets: ​ ​ ​ ​ ​ ​ ​ ​ ​ Certificates of deposit ​ Marketable securities ​ $ — ​ ​ 2,296 ​ ​ — ​ $ 2,296 Interest rate swaps ​ Deposits and other assets ​ ​ — ​ ​ 2,739 ​ ​ — ​ ​ 2,739 Total assets measured at fair value on a recurring basis ​ ​ ​ $ — ​ $ 5,035 ​ $ — ​ $ 5,035 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Liabilities: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Contingent consideration ​ Other current liabilities ​ $ — ​ ​ — ​ ​ 1,738 ​ $ 1,738 Total liabilities measured at fair value on a recurring basis ​ ​ ​ $ — ​ $ — ​ $ 1,738 ​ $ 1,738 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, 2020 Description ​ Balance Sheet Classification ​ Level 1 Level 2 Level 3 Total Fair Value Assets: ​ ​ ​ ​ ​ ​ ​ ​ ​ Certificates of deposit ​ Marketable securities ​ $ — ​ $ 2,654 ​ $ — ​ $ 2,654 Total assets measured at fair value on a recurring basis ​ ​ ​ $ — ​ $ 2,654 ​ $ — ​ $ 2,654 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Liabilities: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Contingent consideration ​ Other current liabilities ​ $ — ​ $ — ​ $ 2,009 ​ $ 2,009 Contingent consideration ​ Other long-term liabilities ​ ​ — ​ ​ — ​ ​ 2,940 ​ ​ 2,940 Interest rate swaps ​ Other long-term liabilities ​ ​ — ​ ​ 2,811 ​ ​ — ​ ​ 2,811 Total liabilities measured at fair value on a recurring basis ​ ​ ​ $ — ​ $ 2,811 ​ $ 4,949 ​ $ 7,760 ​ The fair value of foreign currency forward contracts is based on the movement in the forward rates of foreign currency cash flows in which the hedging instrument is denominated. We determine the fair value of interest rate swaps by estimating the net present value of the expected cash flows based on market rates and associated yield curves, adjusted for non-performance credit risk, as applicable. See Note 8. Derivative Financial Instruments

DERIVATIVE FINANCIAL INSTRUMENT

DERIVATIVE FINANCIAL INSTRUMENTS	12 Months Ended
	Dec. 31, 2021
DERIVATIVE FINANCIAL INSTRUMENTS
DERIVATIVE FINANCIAL INSTRUMENTS	NOTE 8. DERIVATIVE FINANCIAL INSTRUMENTS Changes in foreign currency exchange rates impact us. We may manage these risks through the use of derivative financial instruments, primarily forward contracts with banks. These forward contracts manage the exchange rate risk associated with assets and liabilities denominated in nonfunctional currencies. These derivative instruments are typically executed for one-month periods and not designated as hedges; however, they do economically offset the fluctuations of our assets and liabilities due to foreign exchange rate changes. Gains and losses related to foreign currency exchange contracts were offset by corresponding gains and losses on the revaluation of the underlying assets and liabilities. Both are included as a component of Other income (expense), net in our Consolidated Statements of Operations. As of December 31, 2021 and 2020, there were no foreign currency forward contracts outstanding. In April 2020, we executed interest rate swap contracts with independent financial institutions to partially reduce the variability of cash flows in LIBOR indexed debt interest payments on our Term Loan Facility (under our existing Credit Agreement dated September 10, 2019, as amended). These transactions are accounted for as cash flow hedging instruments. The interest rate swap contracts fixed a portion of the outstanding principal balance on our term loan to a total interest rate of 1.271%. This is comprised of 0.521% average fixed rate per annum in exchange for a variable interest rate based on one-month USD-LIBOR-BBA plus the credit spread in our existing Credit Agreement, which is 75 basis points at current leverage ratios. The following table summarizes the notional amount of our qualified hedging instruments: ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, ​ December 31, ​ 2021 2020 Interest rate swap contracts ​ $ 255,719 ​ $ 273,219 ​ The following table summarizes the amounts recorded in Accumulated other comprehensive loss on the Consolidated Balance Sheets for qualifying hedges. ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, ​ December 31, ​ 2021 2020 Interest rate swap contracts - gains (losses) ​ $ 2,107 ​ $ (2,139) ​ See Note 7. Fair Value Measurements As a result of using derivative financial instruments, we are exposed to the risk that counterparties to contracts could fail to meet their contractual obligations. We manage this risk by reviewing counterparty creditworthiness on a regular basis and limiting exposure to any single counterparty.

ACCOUNTS AND OTHER RECEIVABLE,

ACCOUNTS AND OTHER RECEIVABLE, NET	12 Months Ended
	Dec. 31, 2021
ACCOUNTS AND OTHER RECEIVABLE, NET
ACCOUNTS AND OTHER RECEIVABLE, NET	NOTE 9. ACCOUNTS AND OTHER RECEIVABLE, NET We record accounts and other receivable at net realizable value. Components of accounts and other receivable, net of reserves, were as follows: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, ​ December 31, ​ 2021 2020 Amounts billed, net ​ $ 217,549 ​ $ 213,560 Unbilled receivables ​ ​ 19,678 ​ 21,618 Total receivables, net ​ $ 237,227 ​ $ 235,178 ​ "Amounts billed, net" represents amounts invoiced to customers in accordance with our terms and conditions and reflects an allowance for expected credit losses. These receivables are short term in nature and do not include any financing components. "Unbilled receivables" consist of amounts where we satisfied our contractual obligations associated with customer inventory stocking agreements. Such amounts typically become billable upon the customer's consumption of the inventory. We anticipate invoicing and collecting substantially all unbilled receivables within the next twelve months. The following table summarizes the changes in expected credit losses: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, ​ December 31, ​ 2021 2020 Balance at beginning of period $ 7,602 ​ $ 7,745 Additions ​ 135 ​ 368 Deductions - write-offs, net of recoveries ​ (687) ​ (511) Foreign currency translation ​ ​ (18) ​ ​ — Other ​ ​ (1,248) ​ ​ — Balance at end of period ​ $ 5,784 ​ $ 7,602 ​

INVENTORIES

INVENTORIES	12 Months Ended
	Dec. 31, 2021
INVENTORIES
INVENTORIES	NOTE 10. INVENTORIES We value inventories at the lower of cost or net realizable value and computed on a first-in, first-out basis. Components of inventories were as follows: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, ​ December 31, ​ 2021 2020 Parts and raw materials ​ $ 261,365 ​ $ 141,337 Work in process ​ 24,222 ​ 13,702 Finished goods ​ 52,823 ​ 66,307 Total ​ $ 338,410 ​ $ 221,346 ​

PROPERTY AND EQUIPMENT, NET

PROPERTY AND EQUIPMENT, NET	12 Months Ended
	Dec. 31, 2021
PROPERTY AND EQUIPMENT, NET
PROPERTY AND EQUIPMENT, NET	NOTE 11. PROPERTY AND EQUIPMENT, NET Property and equipment, net is comprised of the following: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Estimated Useful ​ December 31, ​ December 31, ​ Life (in years) 2021 2020 Buildings ​ 25 ​ $ 1,625 ​ $ 1,776 Machinery and equipment ​ 5 to 8 ​ 133,010 ​ 115,404 Computer equipment, furniture, fixtures, and vehicles ​ 3 to 5 ​ 33,490 ​ 31,237 Leasehold improvements ​ 2 to 10 ​ 48,370 ​ 42,984 Construction in process ​ ​ ​ 5,914 ​ 3,693 ​ ​ ​ ​ 222,409 ​ 195,094 Less: Accumulated depreciation ​ ​ ​ (107,579) ​ (80,363) Property and equipment, net ​ ​ ​ $ 114,830 ​ $ 114,731 ​ The following table summarizes depreciation expense. All depreciation expense is recorded in income from continuing operations. ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Years Ended December 31, ​ 2021 2020 2019 Depreciation expense $ 30,833 ​ $ 27,641 ​ $ 13,979 ​

GOODWILL

GOODWILL	12 Months Ended
	Dec. 31, 2021
GOODWILL AND INTANGIBLE ASSETS
GOODWILL	NOTE 12. GOODWILL The following table summarizes the changes in goodwill: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, ​ December 31, ​ 2021 2020 Balance at beginning of period ​ $ 209,983 ​ $ 202,932 Measurement period adjustments to purchase price allocations ​ ​ (1,426) ​ ​ 1,957 Additions from acquisition ​ ​ 5,877 ​ ​ 1,749 Foreign currency translation ​ ​ (2,244) ​ ​ 3,345 Balance at end of period $ 212,190 ​ $ 209,983 ​ Additions and adjustments are the result of business combinations. Refer to Note 2. Acquisitions.

INTANGIBLE ASSETS

INTANGIBLE ASSETS	12 Months Ended
	Dec. 31, 2021
GOODWILL AND INTANGIBLE ASSETS
INTANGIBLE ASSETS	NOTE 13. INTANGIBLE ASSETS Intangible assets consisted of the following: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, 2021 ​ Gross Carrying Accumulated Net Carrying ​ ​ Amount ​ Amortization ​ Amount Technology ​ $ 91,461 ​ $ (35,854) ​ $ 55,607 Customer relationships ​ 118,706 ​ ​ (34,187) ​ 84,519 Trademarks and other ​ 27,244 ​ ​ (7,964) ​ 19,280 Total ​ $ 237,411 ​ $ (78,005) ​ $ 159,406 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, 2020 ​ Gross Carrying Accumulated Net Carrying ​ ​ Amount ​ Amortization ​ Amount Technology ​ $ 85,075 ​ $ (24,999) ​ $ 60,076 Customer relationships ​ 114,171 ​ (26,880) ​ 87,291 Trademarks and other ​ 27,021 ​ (5,449) ​ 21,572 Total ​ $ 226,267 ​ $ (57,328) ​ $ 168,939 ​ At December 31, 2021, the weighted average remaining useful life of intangibles subject to amortization was approximately 9.8 years. Amortization expense related to intangible assets was as follows: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Years Ended December 31, ​ 2021 2020 2019 Amortization expense ​ $ 22,060 ​ $ 20,129 ​ $ 12,168 ​ Estimated amortization expense related to intangibles is as follows: ​ ​ ​ ​ ​ Year Ending December 31, ​ ​ 2022 ​ 22,025 2023 ​ 22,007 2024 ​ 19,148 2025 ​ 14,653 2026 ​ ​ 12,937 Thereafter ​ 68,636 Total ​ $ 159,406 ​

RESTRUCTURING COSTS

RESTRUCTURING COSTS	12 Months Ended
	Dec. 31, 2021
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. For the periods presented, we incurred severance costs primarily related to the transition and exit of our facility in Shenzhen, PRC and actions associated with synergies related to the Artesyn acquisition. The table below summarizes restructuring charges: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Years Ended December 31, ​ ​ 2021 2020 2019 Severance and related charges $ 3,467 ​ $ 9,632 ​ $ 3,042 Facility relocation and closure charges ​ 1,285 ​ 3,534 ​ 1,996 Total restructuring charges ​ $ 4,752 ​ $ 13,166 ​ $ 5,038 ​ ​ ​ ​ ​ ​ ​ Cumulative Cost ​ ​ Through ​ ​ December 31, ​ ​ 2021 Severance and related charges $ 20,380 Facility relocation and closure charges ​ ​ 6,815 Total restructuring charges ​ $ 27,195 ​ Our restructuring liabilities are included in other accrued expenses in our Consolidated Balance Sheets and related primarily to severance and associated costs. Changes in restructuring liabilities were as follows: ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, ​ December 31, ​ ​ 2021 2020 Balance at beginning of period $ 10,641 ​ $ 2,172 Costs incurred and charged to expense ​ ​ 4,752 ​ ​ 13,166 Costs paid or otherwise settled ​ ​ (6,127) ​ ​ (4,714) Effects of changes in exchange rate ​ ​ (3) ​ ​ 17 Balance at end of period ​ $ 9,263 ​ $ 10,641 ​

WARRANTIES

WARRANTIES	12 Months Ended
	Dec. 31, 2021
WARRANTIES
WARRANTIES	NOTE 15. WARRANTIES Our sales agreements include customary product warranty provisions, which range from 12 to 24 months after shipment. We record the estimated warranty obligations cost when we recognize revenue. This estimate is based on 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 were as follows: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Years Ended December 31, ​ 2021 2020 Balance at beginning of period ​ $ 4,780 ​ $ 6,413 Warranty acquired in business combinations ​ ​ — ​ ​ 15 Increases to accruals ​ 3,165 ​ 2,996 Warranty expenditures ​ (4,587) ​ (4,688) Effect of changes in exchange rates ​ (8) ​ 44 Balance at end of period ​ $ 3,350 ​ $ 4,780 ​

LEASES

LEASES	12 Months Ended
	Dec. 31, 2021
LEASES
LEASES	NOTE 16. LEASES Components of operating lease cost were as follows: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Years Ended December 31, ​ 2021 2020 ​ 2019 Operating lease cost ​ $ 23,443 ​ $ 22,920 ​ $ 11,052 Short-term and variable lease cost ​ ​ 2,555 ​ ​ 1,895 ​ ​ 4,726 Total operating lease cost ​ $ 25,998 ​ $ 24,815 ​ $ 15,778 ​ Maturities of our operating lease liabilities are as follows: ​ ​ ​ ​ ​ Year Ending December 31, ​ ​ 2022 ​ $ 20,416 2023 ​ 17,230 2024 ​ 14,812 2025 ​ ​ 12,426 2026 ​ ​ 11,079 Thereafter ​ ​ 65,785 Total lease payments ​ ​ 141,748 Less: Interest ​ ​ (30,725) Present value of lease liabilities ​ $ 111,023 ​ We have lease agreements that commence in the future between 2022 and 2023 with total payments of $4.3 million through 2029. ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Year Ended December 31, ​ ​ ​ 2021 2020 ​ Weighted average remaining lease term (in years) ​ ​ 9.81 ​ ​ 10.65 ​ Weighted average discount rate ​ ​ 4.51 % ​ 4.63 % ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Year Ended December 31, ​ 2021 2020 ​ 2019 Cash paid for operating leases ​ $ 23,668 ​ $ 21,877 ​ $ 12,101 Right-of-use assets obtained in exchange for operating lease liabilities ​ $ 16,399 ​ $ 33,741 ​ $ 84,551 ​

EMPLOYEE RETIREMENT PLANS AND P

EMPLOYEE RETIREMENT PLANS AND POSTRETIREMENT BENEFITS	12 Months Ended
	Dec. 31, 2021
EMPLOYEE RETIREMENT PLANS AND POSTRETIREMENT BENEFITS
EMPLOYEE RETIREMENT PLANS AND POSTRETIREMENT BENEFITS	NOTE 17. EMPLOYEE RETIREMENT PLANS AND POSTRETIREMENT BENEFITS Defined Contribution Plans We have a 401(k) profit-sharing and retirement savings plan covering substantially all full-time U.S. employees. Participants may defer up to the maximum amount allowed permitted by law. Effective January 1, 2022, participants are immediately vested in both their own contributions and profit-sharing contributions. Profit-sharing contributions, which are discretionary, are approved by the Board of Directors. For the years ended December 31, 2021, 2020, and 2019 we based our profit-sharing contribution on matching 50% of employee contributions up to 6% of the employee’s compensation. During the years ended December 31, 2021, 2020, and 2019 we recognized total defined contribution plan costs of $3.1 million, $2.6 million, and $1.6 million, respectively. Defined Benefit Plan We maintain defined benefit pension plans for certain of our non-U.S. employees in the U.K., Germany, and Philippines. Each plan is managed locally and in accordance with respective local laws and regulations. To measure the expense and related benefit obligation, we make various assumptions, including discount rates used to value the obligation, expected return on plan assets used to fund these expenses, and estimated future inflation rates. We base these assumptions on historical experience as well as facts and circumstances. We use an actuarial analysis to measure the expense and liability associated with pension benefits. The information provided below includes one pension plan which is part of discontinued operations. As such, for all periods presented, all related expenses are reported in discontinued operations in the Consolidated Statements of Operations. Our projected benefit obligation and plan assets for defined benefit pension plans and the related assumptions used to determine the related liabilities are as follows: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Years Ended December 31, ​ 2021 2020 Projected benefit obligation, beginning of year ​ $ 97,740 ​ $ 83,262 Service cost ​ 1,282 ​ 1,068 Interest cost ​ 1,452 ​ 1,716 Actuarial (gain) loss ​ (8,682) ​ 7,591 Benefits paid ​ (2,010) ​ (1,199) Translation adjustment ​ (4,006) ​ 5,302 Projected benefit obligation, end of year ​ $ 85,776 ​ $ 97,740 ​ ​ ​ ​ ​ ​ ​ Fair value of plan assets, beginning of year ​ $ 17,293 ​ $ 14,903 Actual return on plan assets ​ 641 ​ 682 Contributions ​ 1,775 ​ 1,827 Benefits paid ​ (1,112) ​ (993) Actuarial gain ​ 71 ​ 180 Translation adjustment ​ (147) ​ 694 Fair value of plan assets, end of year ​ $ 18,521 ​ $ 17,293 Funded status of plan ​ $ (67,255) ​ $ (80,447) ​ The components of net periodic pension benefit cost recognized in our Consolidated Statements of Operations for the periods presented are as follows: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Years Ended December 31, ​ 2021 2020 2019 Service cost ​ $ 1,282 ​ $ 1,068 ​ $ 272 Interest cost ​ ​ 1,452 ​ ​ 1,716 ​ ​ 1,211 Expected return on plan assets ​ (642) ​ (683) ​ (615) Amortization of actuarial gains and losses ​ 820 ​ 459 ​ 411 Net periodic pension cost ​ $ 2,912 ​ $ 2,560 ​ $ 1,279 ​ Assumptions used in the determination of the net periodic pension cost are: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Years Ended December 31, ​ 2021 2020 2019 Discount rate 1.6 % 1.8 % 2.7 % Expected long-term return on plan assets 3.2 % 3.7 % 4.6 % ​ The fair value of our qualified pension plan assets by category was as follows: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, 2021 ​ Level 1 Level 2 Level 3 Total Diversified Growth Fund ​ $ — ​ $ 12,249 ​ $ — ​ $ 12,249 Corporate Bonds ​ — ​ ​ 4,640 ​ ​ — ​ ​ 4,640 Insurance Contracts ​ ​ — ​ ​ — ​ ​ 984 ​ ​ 984 Cash ​ 648 ​ ​ — ​ ​ — ​ ​ 648 Total ​ $ 648 ​ $ 16,889 ​ $ 984 ​ $ 18,521 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, 2020 ​ Level 1 Level 2 Level 3 Total Multi-Asset Fund ​ $ — ​ $ 5,149 ​ $ — ​ $ 5,149 Diversified Growth Fund ​ — ​ 5,134 ​ — ​ 5,134 Corporate Bonds ​ — ​ 4,906 ​ — ​ 4,906 Insurance Contracts ​ ​ — ​ — ​ 1,109 ​ 1,109 Cash ​ 995 ​ — ​ — ​ 995 Total ​ $ 995 ​ $ 15,189 ​ $ 1,109 ​ $ 17,293 ​ On December 31, 2021, our plan’s assets of $18.5 million were invested in cash plus three separate funds including, a diversified growth fund (66.1%), corporate bonds (25.1%), and insurance contracts (5.3%). The growth fund aims to generate an "equity-like" return over an economic cycle with significantly reduced volatility relative to equity markets and has the scope to use a diverse range of asset classes, including equities, bonds, cash, and alternatives (e.g., property, infrastructure, high yield bonds, floating rate debt, private, equity, hedge funds and currency). These investments are intended to provide a degree of protection against changes in the value of our plan’s liabilities related to changes in long-term expectations for interest rates and inflation expectations. Expected future payments during the next ten years for our defined benefit pension plans are as follows: ​ ​ ​ ​ ​ Year Ending December 31, ​ ​ 2022 ​ $ 1,778 2023 ​ ​ 2,068 2024 ​ ​ 2,847 2025 ​ ​ 2,299 2026 ​ ​ 5,395 2027 to 2031 ​ ​ 18,739 ​

STOCK-BASED COMPENSATION

STOCK-BASED COMPENSATION	12 Months Ended
	Dec. 31, 2021
STOCK-BASED COMPENSATION.
STOCK-BASED COMPENSATION	NOTE 18. As of December 31, 2021, we had two active stock-based incentive compensation plan: the 2017 Omnibus Incentive Plan ("the 2017 Plan") and the Employee Stock Purchase Plan ("ESPP"). We issue all new equity compensation grants under these two plans; however, outstanding awards previously issued under inactive plans will continue to vest and remain exercisable in accordance with the terms of the respective plans. Our stock plans are administered by the Board of Directors Compensation Committee. On December 31, 2021, there were 3.3 million shares reserved and 2.6 million shares available for future grant under our stock-based incentive plans. On May 4, 2017, the stockholders approved the 2017 Plan, and all shares that were then available for issuance under the 2008 Omnibus Incentive Plan ("the 2008 Plan") are now available for issuance under the 2017 Plan. The 2017 Plan and 2008 Plan provide 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 may be issued as performance-based awards to align stock compensation awards to the attainment of annual or long-term performance goals. As of December 31, 2021, there were 1.9 million shares available for grant under the 2017 Plan. Stock-based Compensation Expense 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 was as follows: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Years Ended December 31, ​ 2021 2020 2019 Equity classified awards ​ $ 15,428 ​ $ 12,272 ​ $ 7,327 Liability classified awards ​ ​ 311 ​ ​ — ​ ​ — Stock-based compensation expense ​ $ 15,739 ​ $ 12,272 ​ $ 7,327 ​ Estimated forfeiture rates for our stock-based compensation expense applicable to stock options and RSUs were approximately 8%, 5% and 10% for the years ended December 31, 2021, 2020 and 2019, respectively. Restricted Stock Units Generally, we grant RSUs with a three-year time-based vesting schedule. Certain RSUs contain performance-based or market-based vesting conditions in addition to the time-based vesting requirements. ​ Changes in our unvested RSUs were as follows: ​ ​ ​ ​ ​ ​ ​ ​ ​ Year Ended December 31, 2021 ​ ​ Weighted- ​ ​ ​ ​ Average ​ ​ Number of ​ Grant Date ​ ​ RSUs ​ Fair Value RSUs outstanding at beginning of period 608 ​ $ 58.15 RSUs granted 406 ​ $ 94.60 RSUs vested (178) ​ $ 62.82 RSUs forfeited (209) ​ $ 70.34 RSUs outstanding at end of period 627 ​ $ 76.37 ​ The total intrinsic value of RSUs converted to shares for the years ended December 31, 2021, 2020 and 2019 were $19.2 million, $9.2 million, and $8.3 million, respectively. As of December 31, 2021, there was $21.4 million of total unrecognized compensation cost, net of expected forfeitures related to non-vested RSUs granted, which is expected to be recognized through December 2024, with a weighted-average remaining vesting period of 1.1 years. Stock Options Generally, we grant stock option awards with an exercise price equal to the market price of our stock at the date of grant and with either a three Changes in our stock options were as follows: ​ ​ ​ ​ ​ ​ ​ ​ ​ Year Ended December 31, 2021 ​ ​ Weighted- ​ ​ ​ ​ Average ​ ​ Number of ​ Exercise Price ​ ​ Options ​ per Share Options outstanding at beginning of period 147 ​ $ 23.63 Options exercised (35) ​ $ 21.10 Options outstanding at end of period 112 ​ $ 24.41 ​ The total intrinsic value of options exercised for the years ended December 31, 2021, 2020 and 2019 was $2.6 million, $1.9 million, and $1.6 million, respectively. All options outstanding on December 31, 2021 are vested and have aggregate intrinsic value of $7.5 million and weighted-average remaining contractual life of 3.0 years. The following table summarizes information about the stock options outstanding on December 31, 2021: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Options Outstanding and Exercisable ​ ​ Number ​ Weighted-Average ​ Weighted- ​ ​ Outstanding ​ Remaining ​ Average Range of Exercise Prices (In 000's) Contractual Life Exercise Price $18.77 28 2.75 years ​ $ 18.77 $26.32 84 3.10 years ​ $ 26.32 $18.77 to $26.32 112 3.01 years ​ $ 24.41 ​ Employee Stock Purchase Plan The ESPP, a stockholder-approved plan, provides for the issuance of rights to purchase up to 1,000,000 shares of common stock. In May 2010, stockholders approved an increase from 500,000 to 1,000,000 shares authorized for sale under our ESPP. Employees below the Vice President level are eligible to participate in the ESPP if employed by us for at least 20 hours per week during at least five months per calendar year. Participating employees may contribute up to the lesser of 15% of their eligible earnings or $5,000 during each plan period. Currently, the plan period is six months. The purchase price of common stock purchased under the ESPP is currently equal to the lower of 1) 85% of the fair market value of our common stock on the commencement date of each plan period or 2) 85% of the fair market value of our common shares on each plan period purchase date. On December 31, 2021, 0.7 million shares remained available for future issuance under the ESPP. Purchase rights granted under the ESPP are valued using the Black-Scholes-Merton model. As of December 31, 2021, there was $0.6 million of total unrecognized compensation cost related to the ESPP that we expect to recognize over a remaining period of five months. The following table summarizes compensation expense related to the ESPP. ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Years Ended December 31, ​ 2021 2020 2019 Stock-based compensation expense related to the ESPP ​ $ 1,114 ​ $ 856 ​ $ 475 ​ The fair value of each purchase right granted under the ESPP was estimated on the date of grant using the Black-Scholes-Merton option pricing model with the following assumptions: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Years Ended December 31, ​ ​ 2021 2020 2019 Risk-free interest rates 0.04% - 0.10 % 0.10% - 0.18% % 1.62% - 2.31 % Expected dividend yield rates — % — % — % Expected term 0.5 years 0.5 years 0.5 years ​ Expected volatility 42.7 % 70.1 % 41.3 % ​ The risk-free interest rate is based on the six-month U.S. Treasury Bill at the time of the grant. Our term is 0.5 years as purchases are made biannually. We utilize our historical experience in determining the volatility of our common stock over the expected term.

COMMITMENTS AND CONTINGENCIES

COMMITMENTS AND CONTINGENCIES	12 Months Ended
	Dec. 31, 2021
COMMITMENTS AND CONTINGENCIES
COMMITMENTS AND CONTINGENCIES	NOTE 19. COMMITMENTS AND CONTINGENCIES We are involved in disputes and legal actions arising in the normal course of our business. While we currently believe that the amount of any ultimate loss would not be material to our financial position, the outcome of these actions is inherently difficult to predict. In the event of an adverse outcome, the ultimate loss could have a material adverse effect on our financial position or reported results of operations. An unfavorable decision in patent litigation also could require material changes in production processes and products or result in our inability to ship products or components found to have violated third-party patent rights. We accrue loss contingencies in connection with our commitments and contingencies, including litigation, when it is probable that a loss has occurred, and the amount of the loss can be reasonably estimated. We are not currently a party to any legal action that we believe would reasonably have a material adverse impact on our business, financial condition, results of operations or cash flows.

GEOGRAPHIC AND SIGNIFICANT CUST

GEOGRAPHIC AND SIGNIFICANT CUSTOMER INFORMATION	12 Months Ended
	Dec. 31, 2021
GEOGRAPHIC AND SIGNIFICANT CUSTOMER INFORMATION
GEOGRAPHIC AND SIGNIFICANT CUSTOMER INFORMATION	NOTE 20. GEOGRAPHIC AND SIGNIFICANT CUSTOMER INFORMATION The following table summarizes sales and percentages of total sales from customers who individually accounted for 10% or more of our sales: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Years Ended December 31, ​ ​ 2021 ​ 2020 ​ 2019 ​ Applied Materials, Inc. ​ $ 296,369 20.4 % ​ $ 248,350 17.5 % ​ $ 164,724 20.9 % Lam Research Corporation ​ 147,385 10.1 % ​ 141,778 10.0 % ​ 88,251 11.2 % ​ The following table summarizes the accounts receivable balances and percentages of the total accounts receivable from customers who individually accounted for 10% or more of accounts receivable: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, ​ December 31, ​ ​ ​ 2021 ​ ​ 2020 ​ Applied Materials, Inc. ​ $ 42,425 17.9 % $ 33,402 14.2 % Nidec Motor Corporation ​ ​ * ​ * % $ 24,344 ​ 10.4 % * Customer’s balance was less than 10% of total Our sales to Applied Materials, Inc. and Lam Research Corporation are reflected in the Semiconductor Equipment and Industrial and Medical market. Our sales to Nidec Motor Corporation are reflected in the Industrial and Medical market. For more information on our markets, see Note 3. Revenue No other customer accounted for 10% or more of our sales or accounts receivable balances during these periods. The following table summarizes long-lived assets by geographic area: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, ​ 2021 2020 United States ​ $ 255,791 ​ $ 253,115 Asia ​ 275,260 ​ 283,549 Europe ​ 57,144 ​ 60,847 Total ​ $ 588,195 ​ $ 597,511 ​ Long-lived assets include property and equipment, operating lease right-of-use assets goodwill, and intangible assets.

CREDIT FACILITY

CREDIT FACILITY	12 Months Ended
	Dec. 31, 2021
CREDIT FACILITY
CREDIT FACILITY	NOTE 21. CREDIT FACILITY In September 2019, in connection with the Artesyn Acquisition Agreement, we 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" and together with the Term Loan Facility, the “Credit Facility”). In September 2021, we amended the Credit Agreement whereby we borrowed an additional $85.0 million, which increased the aggregate amount outstanding under the Term Loan Facility to $400.0 million. In addition, we increased the Revolving Facility capacity by $50.0 million to $200.0 million. Both the Term Loan Facility and Revolving Facility mature on September 9, 2026. The following table summarizes borrowings under our Credit Facility and the associated interest rate. ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, 2021 ​ ​ Balance Interest Rate Unused Line Fee Term Loan Facility subject to a fixed interest rate ​ $ 255,719 ​ 1.271% ​ — Term Loan Facility subject to a variable interest rate ​ ​ 139,281 ​ 0.890% ​ — Revolving Facility subject to a variable interest rate ​ ​ — ​ 0.890% ​ 0.10% Total borrowings under the Credit Agreement ​ $ 395,000 ​ ​ ​ ​ ​ For more information on the interest rate swap that fixes the interest rate for a portion of our Term Loan Facility, see Note 8. Derivative Financial Instruments For all periods presented, we were in compliance with the Credit Agreement covenants. As of December 31, 2021 and December 31, 2020, we had $200.0 million and $150.0 million, respectively, available to withdraw on the Revolving Facility. The fair value of the Term Loan Facility approximates the outstanding balance of $395.0 million as of December 31, 2021 . The debt obligation on our Consolidated Balance Sheets consists of the following: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, ​ December 31, ​ 2021 2020 Term Loan Facility ​ $ 395,000 ​ $ 323,750 Less: debt issuance costs ​ ​ (2,267) ​ ​ (1,704) Total debt ​ ​ 392,733 ​ ​ 322,046 Less current portion of long-term debt ​ ​ (20,000) ​ ​ (17,500) Total long-term debt ​ $ 372,733 ​ $ 304,546 ​ Contractual maturities of our debt obligations, excluding amortization of debt issuance costs, are as follows: ​ ​ ​ ​ ​ Year Ending December 31, ​ 2022 ​ $ 20,000 2023 ​ ​ 20,000 2024 ​ ​ 20,000 2025 ​ ​ 20,000 2026 ​ ​ 315,000 Total ​ $ 395,000 ​ Interest expense and unused line of credit fees were recorded in Other income (expense), net in our Consolidated Statements of Operations as follows: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Years Ended December 31, ​ 2021 2020 2019 Interest expense ​ $ 3,969 ​ $ 5,080 ​ $ 2,994 Amortization of debt issuance costs ​ ​ 822 ​ ​ 519 ​ ​ 186 Unused line of credit fees and other ​ ​ 168 ​ ​ 153 ​ ​ 236 Total interest expense ​ $ 4,959 ​ $ 5,752 ​ $ 3,416 ​

OPERATIONS AND SUMMARY OF SIG_2

OPERATIONS AND SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES AND ESTIMATES (Policies)	12 Months Ended
	Dec. 31, 2021
OPERATIONS AND SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES AND ESTIMATES
Principles of Consolidation	Principles of Consolidation
Use of Estimates in the Preparation of the Consolidated Financial Statements	Use of Estimates in the Preparation of the Consolidated Financial Statements — ● excess and obsolete inventory; ● pension obligations; ● acquisitions and asset valuations, and ● taxes and other provisions.
Foreign Currency Translation	Foreign Currency Translation — For certain other subsidiaries, the functional currency is the U.S. Dollar. Foreign currency transactions are recorded based on exchange rates at the time such transactions arise. Subsequent changes in exchange rates for foreign currency denominated monetary assets and liabilities result in foreign currency transaction gains and losses, which are reflected as unrealized (based on period end remeasurement) or realized (upon settlement of the transactions) in Other income (expense), net in our Consolidated Statements of Operations.
Derivatives	Derivatives — We use derivative financial instruments to manage risks associated with foreign currency and interest rate fluctuations. Unless we meet specific hedge accounting criteria, changes in the fair value of derivative financial instruments are recognized in the Consolidated Statements of Operations within Other income (expense), net. For derivatives designated as cash flow hedges, changes in fair value are recorded to Accumulated other comprehensive loss on the Consolidated Balance Sheets and are reclassified to earnings when the underlying forecasted transaction affects earnings. We reassess the probability of the underlying forecasted transactions occurring on a quarterly basis.
Fair Value	Fair Value — U.S. GAAP for fair value establishes a hierarchy that prioritizes fair value measurements based on the types of inputs used for the various valuation techniques (market approach, income approach, and cost approach). Our financial assets and liabilities are measured using inputs from the three levels of the fair value hierarchy. The three levels of the hierarchy and the related inputs are as follows: ● Level 1 — Quoted prices (unadjusted) in active markets for identical assets or liabilities that the entity can access on the measurement date. ● Level 2 — Inputs other than quoted prices included within Level 1 that are observable for the asset or liability, either directly or indirectly. ● Level 3 — Unobservable inputs for the asset or liability. We categorize fair value measurements within the fair value hierarchy based upon the lowest level of the most significant inputs used to determine fair value. Our assessment of the significance of a particular input to the fair value measurement requires judgment and may affect the valuation of the fair value of assets and liabilities and their placement within the fair value hierarchy levels. The carrying amounts of our cash and cash equivalents, accounts receivable, accounts payable and other current assets and liabilities approximate fair value as recorded due to the short-term nature of these instruments. Our non-financial assets, which primarily consist of property and equipment, goodwill, and other intangible assets, are not required to be carried at fair value on a recurring basis and are reported at carrying value. However, on a periodic basis or whenever events or changes in circumstances indicate that their carrying value may not be fully recoverable (and at least annually for goodwill), non-financial instruments are assessed for impairment and, if applicable, written down to and recorded at fair value. See Note 12. Goodwill Note 13. Intangible Assets The fair value of borrowings approximates the recorded borrowing value based upon market interest rates for similar facilities. See Note 21. Credit Facility
Cash, Cash Equivalents, and Marketable Securities	Cash, Cash Equivalents, and Marketable Securities In some instances, we invest excess cash in money market funds not insured by the Federal Deposit Insurance Corporation. We believe the investments in money market funds are on deposit with credit-worthy financial institutions and the funds are highly liquid. These investments are reported at fair value and included in Cash and cash equivalents. We record interest income within Other income (expense), net in our Consolidated Statement of Operations. We classify investments with stated maturities of greater than three months at time of purchase as marketable securities.
Concentrations of Credit Risk	Concentrations of Credit Risk — We establish a reserve for credit losses based upon factors surrounding the credit risk of specific customers, historical trends, and other information.
Accounts Receivable and Reserve for Credit Losses	Accounts Receivable and Reserve for Credit Losses —
Inventories	Inventories
Property and Equipment	Property and Equipment When depreciable assets are retired, or otherwise disposed of, the cost and related accumulated depreciation are removed from the accounts, and any related gains or losses are included in Other income (expense), net, in our Consolidated Statements of Operations.
Purchase accounting	Purchase accounting
Leases	Leases Right-of-use assets and operating lease liabilities are recognized at the present value of the future lease payments on the lease commencement date. The interest rate used to determine the present value of the future lease payments is our incremental borrowing rate because the interest rate implicit in our leases is not readily determinable. Our incremental borrowing rate is estimated to approximate the interest rate on a collateralized basis with similar terms and payments. We have a centrally managed treasury function; therefore, we apply a portfolio approach for determining the incremental borrowing rate applicable to the lease term. Operating lease expense is recognized on a straight-line basis over the lease term.
Intangible Assets, Goodwill and Other Long-Lived Assets	Intangible Assets, Goodwill, and Other Long-Lived Assets The estimation of useful lives and expected cash flows requires us to make judgments regarding future periods that are subject to some factors outside of our control. Changes in these estimates can result in revisions to our carrying value of these assets and may result in material charges to our results of operations. We conduct an annual goodwill impairment analysis using an assessment of qualitative factors in determining if it is more likely than not that goodwill is impaired. If this assessment indicates that it is more likely than not that goodwill is impaired, the next step of impairment testing compares the fair value of a reporting unit to its carrying value. Goodwill would be impaired if the resulting implied fair value of goodwill was less than the recorded carrying value of the goodwill.
Debt Issuance Costs	Debt Issuance Costs Amortization of debt issuance costs is reflected in Other income (expense), net on the Consolidated Statements of Operations. See Note 21. Credit Facility
Revenue Recognition	Revenue Recognition We maintain a worldwide support organization in ten countries, including the U.S., the People's Republic of China ("PRC"), Japan, Korea, Taiwan, Germany, Ireland, Singapore, Israel, and Great Britain. 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.
Research and Development Expenses	Research and Development Expenses
Warranty Costs	Warranty Costs five Note 4. Disposed and Discontinued Operations Note 15. Warranties
Stock-Based Compensation	Stock-Based Compensation We estimate the fair value of restricted stock units ("RSUs") on the grant date. For RSUs that contain a time-based and/or performance-based vesting condition, we estimate fair value using the closing share price on the grant date. We record stock-based compensation expense for awards with time-based vesting conditions over the term of the award. For awards with a performance-based vesting condition, we record stock-based compensation expense (based on management's assessment of the probability of meeting the performance conditions) over the estimated period to achieve the performance conditions. Upon forfeiture or expiration of these awards, we reverse the stock-based compensation expense. Certain RSUs vest based on a market condition. We estimate the fair value and probability of achievement for each tranche of these awards using a Monte Carlo simulation. Because the probability of achievement is a factor in the Monte Carlo simulation, we recognize stock-based compensation expense over each tranche’s estimated achievement period even if some or all of the shares never vest. We estimate the fair value of the purchase rights in our employee stock purchase plan using a Black-Scholes Merton option pricing model and recognize compensation expense over the term of the purchase right. For all stock awards, we estimate forfeitures at the grant date and revise those estimates in subsequent periods if actual forfeitures differ from our estimates.
Income Taxes	Income Taxes We assess the recoverability of our net deferred tax assets and the need for a valuation allowance on a quarterly basis. Our assessment includes several factors including historical results and taxable income projections for each jurisdiction. The ultimate realization of deferred income tax assets is dependent on the generation of taxable income in appropriate jurisdictions during the periods in which those temporary differences are deductible. We consider the scheduled reversal of deferred income tax liabilities, projected future taxable income, and tax planning strategies in determining the amount of the valuation allowance. Based on the level of historical taxable income and projections for future taxable income over the periods in which the deferred income tax assets are deductible, we determine if we will realize the benefits of these deductible differences. Accounting for income taxes requires a two-step approach to recognize and measure uncertain tax positions. In general, we are subject to regular examination of our income tax returns by the Internal Revenue Service and other tax authorities. The first step is to evaluate the tax position for recognition by determining, if based on the technical merits, it is more likely than not that the position will be sustained upon audit, including resolutions of related appeals or litigation processes, if any. The second step is to measure the tax benefit as the largest amount that is more than 50% likely of being realized upon ultimate settlement. We regularly assess the likelihood of favorable or unfavorable outcomes resulting from these examinations to determine the adequacy of our provision for income taxes. This evaluation is based on factors including, but not limited to, changes in facts or circumstances, changes in tax law, effectively settled issues under audit, and new audit activity. Under U.S. GAAP, an accounting policy election can be made to either recognize deferred taxes for temporary basis differences expected to reverse as global intangible low-tax income ("GILTI") in future years, or to provide for the tax expense related to GILTI in the year the tax is incurred as a period expense only. We have elected to account for GILTI in the year the tax is incurred.
Commitments and Contingencies	Commitments and Contingencies
New Accounting Standards	NEW ACCOUNTING STANDARDS 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, will not have a material impact on the consolidated financial statements upon adoption. New Accounting Standards Adopted 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 was effective for us on January 1, 2021. The impact of adoption was not material to our consolidated financial statements. New Accounting Standards In March 2020, the FASB issued ASU 2020-04, "Reference Rate Reform (Topic 848): Facilitation of the Effects of Reference Rate Reform on Financial Reporting" "Reference Rate Reform (Topic 848): Scope" ​ Our Credit Facility (refer to Note 21. Credit Facility Note 8. Derivative Financial Instruments Note 21. Credit Facility In October 2021, the FASB issued ASU 2021-08, " Business Combinations (Topic 806) Accounting for Contract Assets and Contract Liabilities from Contracts with Customers." will improve the accounting for acquired revenue contracts with customers in a business combination. This pronouncement will be effective for us on January 1, 2023. We are still evaluating the impact, if any, that the adoption of ASU 2021-08 may have on our consolidated financial statements.

ACQUISITIONS (Tables)

ACQUISITIONS (Tables)	12 Months Ended
	Dec. 31, 2021
TEGAM, Inc. [Member]
Business Acquisition [Line Items]
Schedule of components of fair value of total consideration transferred	​ ​ ​ ​ ​ Cash paid for acquisition $ 15,430 Holdback ​ ​ 1,800 Total fair value of consideration transferred ​ ​ 17,230 Less cash acquired ​ ​ (177) Total purchase price ​ $ 17,053
Schedule of fair value of assets acquired and liabilities assumed	​ ​ ​ ​ ​ ​ Preliminary Fair Value Current assets and liabilities, net ​ $ 3,536 Property and equipment ​ ​ 734 Operating lease right-of-use assets ​ ​ 425 Intangible assets ​ ​ 6,900 Goodwill (deductible for tax purposes) ​ ​ 5,877 Other non-current assets ​ ​ 31 Total assets acquired ​ ​ 17,503 Other non-current liabilities ​ ​ 25 Operating lease liability ​ ​ 425 Total liabilities assumed ​ ​ 450 Total fair value of net assets acquired ​ $ 17,053
Summary of intangible assets	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Amortization ​ ​ ​ ​ Method Useful Life Technology ​ $ 1,100 Straight-line 5 Customer relationships ​ 5,500 Straight-line 15 Tradename ​ 300 Straight-line 5 Total ​ $ 6,900
Versatile Power, Inc[Member]
Business Acquisition [Line Items]
Schedule of components of fair value of total consideration transferred	​ ​ ​ ​ ​ Cash paid for acquisition $ 4,654 Holdback ​ ​ 950 Total fair value of consideration transferred ​ ​ 5,604 Less cash acquired ​ ​ (245) Total purchase price ​ $ 5,359
Schedule of fair value of assets acquired and liabilities assumed	​ ​ ​ ​ ​ ​ Fair Value Current assets and liabilities, net ​ $ 1,021 Property and equipment ​ ​ 35 Operating lease right-of-use assets ​ ​ 463 Intangible assets ​ ​ 4,000 Goodwill (deductible for tax purposes) ​ ​ 323 Total assets acquired ​ ​ 5,842 Other non-current liabilities ​ ​ 20 Operating lease liability ​ ​ 463 Total liabilities assumed ​ ​ 483 Total fair value of net assets acquired ​ $ 5,359
Summary of intangible assets	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Amortization ​ ​ ​ ​ ​ ​ Method ​ Useful Life Technology ​ $ 400 Straight-line 5 Customer relationships ​ 3,600 Straight-line 15 Total ​ $ 4,000

REVENUE (Tables)

REVENUE (Tables)	12 Months Ended
	Dec. 31, 2021
REVENUE
Summary of deferred revenue	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, ​ December 31, ​ 2021 2020 Deferred revenue ​ $ 7,067 ​ $ 8,671
Schedule of disaggregation of revenue	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Years Ended December 31, ​ ​ ​ 2021 2020 2019 Semiconductor Equipment ​ ​ $ 710,174 ​ $ 611,864 ​ $ 403,018 Industrial and Medical ​ ​ 341,176 ​ 313,646 ​ 245,992 Data Center Computing ​ ​ ​ 270,924 ​ ​ 322,539 ​ ​ 91,438 Telecom and Networking ​ ​ ​ 133,680 ​ ​ 167,777 ​ ​ 48,500 Total ​ ​ $ 1,455,954 ​ $ 1,415,826 ​ $ 788,948 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Years Ended December 31, ​ 2021 2020 2019 United States ​ ​ $ 561,312 ​ 38.5 % $ 530,965 ​ 37.5 % $ 321,869 ​ 40.8 % North America (excluding U.S.) ​ ​ ​ 104,167 7.2 ​ ​ 156,856 11.1 ​ ​ 51,765 6.6 ​ Asia ​ ​ 597,830 41.1 ​ 606,893 42.9 ​ 295,155 37.4 ​ Europe ​ ​ 179,056 12.3 ​ 117,989 8.3 ​ 119,427 15.1 ​ Other ​ ​ 13,589 0.9 ​ 3,123 0.2 ​ 732 0.1 ​ Total ​ ​ $ 1,455,954 100.0 % $ 1,415,826 100.0 % $ 788,948 100.0 % ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Years Ended December 31, ​ 2021 2020 2019 Product ​ $ 1,318,213 ​ $ 1,296,867 ​ $ 678,061 Services ​ ​ 137,741 ​ 118,959 ​ 110,887 Total ​ $ 1,455,954 $ 1,415,826 $ 788,948

INCOME TAXES (Tables)

INCOME TAXES (Tables)	12 Months Ended
	Dec. 31, 2021
INCOME TAXES
Schedule of geographic distribution of pretax income from continuing operations	The geographic distribution of pretax income from continuing operations was as follows: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Years Ended December 31, ​ 2021 2020 2019 Domestic ​ $ 24,541 ​ $ 17,526 ​ $ (20,597) Foreign ​ 124,170 ​ 140,621 ​ 87,791 ​ ​ $ 148,711 ​ $ 158,147 ​ $ 67,194
Schedule of tax expense and the effective tax rate for income from continuing operations	The provision for income taxes from continuing operations is summarized as follows: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Years Ended December 31, ​ 2021 2020 2019 Current: ​ ​ ​ Federal ​ $ (2,468) ​ $ 5,475 ​ $ (9,627) State ​ 929 ​ 1,927 ​ 882 Foreign ​ 14,217 ​ 16,216 ​ 18,429 Total current provision ​ ​ 12,678 ​ ​ 23,618 ​ ​ 9,684 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Deferred: ​ ​ ​ Federal ​ ​ 762 ​ ​ (312) ​ ​ 3,822 State ​ (200) ​ 1,270 ​ (178) Foreign ​ 764 ​ (1,580) ​ (2,629) Total deferred provision (benefit) ​ 1,326 ​ (622) ​ 1,015 Total provision for income taxes ​ $ 14,004 ​ $ 22,996 ​ $ 10,699
Schedule of effective income tax rate reconciliation	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Years Ended December 31, ​ 2021 2020 2019 Income taxes per federal statutory rate ​ $ 31,229 ​ $ 33,211 ​ $ 14,111 State income taxes, net of federal deduction ​ ​ 534 ​ ​ 2,793 ​ ​ 10 U.S. tax on foreign operations ​ ​ 5,786 ​ ​ 9,666 ​ ​ 5,805 Foreign derived intangible income deduction ​ ​ (3,927) ​ ​ (4,070) ​ ​ — Tax effect of foreign operations ​ ​ (11,520) ​ ​ (20,527) ​ ​ (13,086) Uncertain tax positions ​ ​ (6,899) ​ ​ (3,215) ​ ​ (4,487) Audit settlements ​ ​ 7,764 ​ ​ — ​ ​ — Unremitted earnings ​ ​ 261 ​ ​ (567) ​ ​ 1,624 Tax credits ​ ​ (6,149) ​ ​ (2,292) ​ ​ (2,088) Change in valuation allowance ​ ​ (73) ​ ​ (1,175) ​ ​ 7,222 Withholding taxes ​ ​ 756 ​ ​ 4,265 ​ ​ 6,500 Executive compensation limitation ​ ​ 1,926 ​ ​ 1,070 ​ ​ 356 Other permanent items, net ​ ​ (5,684) ​ ​ 3,837 ​ ​ (5,268) Total provision for income taxes ​ $ 14,004 ​ $ 22,996 ​ $ 10,699
Schedule of deferred tax assets and liabilities	​ ​ ​ ​ ​ ​ ​ ​ ​ Years Ended December 31, ​ 2021 2020 Deferred tax assets ​ ​ Stock-based compensation ​ $ 2,528 ​ $ 2,130 Net operating loss and tax credit carryforwards ​ 54,210 ​ 57,590 Interest expense limitation ​ ​ 7,344 ​ ​ 7,344 Pension obligation ​ 10,778 ​ 14,297 Excess and obsolete inventory ​ 3,325 ​ 3,722 Accrued restructuring ​ ​ 2,223 ​ ​ 2,468 Deferred revenue ​ 4,195 ​ 3,048 Employee bonuses and commissions ​ 3,861 ​ 5,388 Amortization ​ 26,358 ​ 28,786 Operating lease liabilities ​ ​ 19,405 ​ ​ 20,267 Other ​ 8,017 ​ 8,925 Deferred tax assets ​ 142,244 ​ 153,965 Less: Valuation allowance ​ (42,051) ​ (46,702) Net deferred tax assets ​ 100,193 ​ 107,263 ​ ​ ​ ​ ​ ​ ​ Deferred tax liabilities ​ ​ ​ Depreciation and amortization ​ 37,515 ​ 40,266 Unremitted earnings ​ 4,435 ​ 4,173 Operating lease right-of-use assets ​ ​ 17,558 ​ ​ 18,731 Other ​ 3,364 ​ 3,380 Deferred tax liabilities ​ 62,872 ​ 66,550 Net deferred tax assets ​ $ 37,321 ​ $ 40,713
Summary of income tax contingencies	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Years Ended December 31, ​ 2021 2020 2019 Balance at beginning of period ​ $ 9,673 ​ $ 13,009 ​ $ 13,162 Additions based on tax positions taken during a prior period ​ 963 ​ 219 ​ 484 Additions based on tax positions taken during a prior period - acquisitions ​ — ​ — ​ 4,479 Additions based on tax positions taken during the current period ​ 566 ​ — ​ — Reductions based on tax positions taken during a prior period ​ — ​ — ​ (4,295) Reductions related to a lapse of applicable statute of limitations ​ (4,575) ​ (3,555) ​ (821) Reductions related to a settlement with taxing authorities ​ (1,114) ​ — ​ — Balance at end of period ​ $ 5,513 ​ $ 9,673 ​ $ 13,009

EARNINGS PER SHARE (Tables)

EARNINGS PER SHARE (Tables)	12 Months Ended
	Dec. 31, 2021
EARNINGS PER SHARE
Reconciliation of weighted-average shares outstanding used in calculation of basic and diluted EPS	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Years Ended December 31, ​ 2021 2020 2019 Income from continuing operations $ 134,707 ​ $ 135,151 ​ $ 56,495 Less: income from continuing operations attributable to noncontrolling interest 44 ​ 55 ​ 34 Income from continuing operations attributable to Advanced Energy Industries, Inc. $ 134,663 ​ $ 135,096 ​ $ 56,461 ​ ​ ​ ​ ​ ​ ​ ​ ​ Basic weighted-average common shares outstanding 38,143 ​ 38,314 ​ 38,281 Assumed exercise of dilutive stock options and restricted stock units 212 ​ 228 ​ 214 Diluted weighted-average common shares outstanding 38,355 ​ 38,542 ​ 38,495 ​ ​ ​ ​ ​ ​ ​ ​ ​ Continuing operations: ​ ​ Basic earnings per share $ 3.53 ​ $ 3.53 ​ $ 1.47 Diluted earnings per share $ 3.51 ​ $ 3.51 ​ $ 1.47
Schedule of repurchase of shares of common stock	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Years Ended December 31, (in thousands, except per share amounts) 2021 2020 Amount paid to repurchase shares ​ $ 78,125 ​ $ 11,630 Number of shares repurchased ​ 901 ​ 244 Average repurchase price per share ​ $ 86.76 ​ $ 47.75 Remaining authorized by Board of Directors for future repurchases as of period end ​ $ 128,377 ​ $ 38,369

FAIR VALUE MEASUREMENTS (Tables

FAIR VALUE MEASUREMENTS (Tables)	12 Months Ended
	Dec. 31, 2021
FAIR VALUE MEASUREMENTS
Schedule of assets and liabilities measured at fair value on a recurring basis	The following tables present information about our assets and liabilities measured at fair value on a recurring basis. ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, 2021 Description ​ Balance Sheet Classification ​ Level 1 ​ Level 2 ​ Level 3 ​ Total Fair Value Assets: ​ ​ ​ ​ ​ ​ ​ ​ ​ Certificates of deposit ​ Marketable securities ​ $ — ​ ​ 2,296 ​ ​ — ​ $ 2,296 Interest rate swaps ​ Deposits and other assets ​ ​ — ​ ​ 2,739 ​ ​ — ​ ​ 2,739 Total assets measured at fair value on a recurring basis ​ ​ ​ $ — ​ $ 5,035 ​ $ — ​ $ 5,035 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Liabilities: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Contingent consideration ​ Other current liabilities ​ $ — ​ ​ — ​ ​ 1,738 ​ $ 1,738 Total liabilities measured at fair value on a recurring basis ​ ​ ​ $ — ​ $ — ​ $ 1,738 ​ $ 1,738 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, 2020 Description ​ Balance Sheet Classification ​ Level 1 Level 2 Level 3 Total Fair Value Assets: ​ ​ ​ ​ ​ ​ ​ ​ ​ Certificates of deposit ​ Marketable securities ​ $ — ​ $ 2,654 ​ $ — ​ $ 2,654 Total assets measured at fair value on a recurring basis ​ ​ ​ $ — ​ $ 2,654 ​ $ — ​ $ 2,654 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Liabilities: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Contingent consideration ​ Other current liabilities ​ $ — ​ $ — ​ $ 2,009 ​ $ 2,009 Contingent consideration ​ Other long-term liabilities ​ ​ — ​ ​ — ​ ​ 2,940 ​ ​ 2,940 Interest rate swaps ​ Other long-term liabilities ​ ​ — ​ ​ 2,811 ​ ​ — ​ ​ 2,811 Total liabilities measured at fair value on a recurring basis ​ ​ ​ $ — ​ $ 2,811 ​ $ 4,949 ​ $ 7,760

DERIVATIVE FINANCIAL INSTRUME_2

DERIVATIVE FINANCIAL INSTRUMENTS (Tables)	12 Months Ended
	Dec. 31, 2021
DERIVATIVE FINANCIAL INSTRUMENTS
Schedule of notional amount of qualified hedging instruments	The following table summarizes the notional amount of our qualified hedging instruments: ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, ​ December 31, ​ 2021 2020 Interest rate swap contracts ​ $ 255,719 ​ $ 273,219
Schedule of balances recorded in Accumulated other comprehensive loss	The following table summarizes the amounts recorded in Accumulated other comprehensive loss on the Consolidated Balance Sheets for qualifying hedges. ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, ​ December 31, ​ 2021 2020 Interest rate swap contracts - gains (losses) ​ $ 2,107 ​ $ (2,139)

ACCOUNTS AND OTHER RECEIVABLE_2

ACCOUNTS AND OTHER RECEIVABLE, NET (Tables)	12 Months Ended
	Dec. 31, 2021
ACCOUNTS AND OTHER RECEIVABLE, NET
Schedule of accounts and other receivable	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, ​ December 31, ​ 2021 2020 Amounts billed, net ​ $ 217,549 ​ $ 213,560 Unbilled receivables ​ ​ 19,678 ​ 21,618 Total receivables, net ​ $ 237,227 ​ $ 235,178
Schedule of expected credit losses	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, ​ December 31, ​ 2021 2020 Balance at beginning of period $ 7,602 ​ $ 7,745 Additions ​ 135 ​ 368 Deductions - write-offs, net of recoveries ​ (687) ​ (511) Foreign currency translation ​ ​ (18) ​ ​ — Other ​ ​ (1,248) ​ ​ — Balance at end of period ​ $ 5,784 ​ $ 7,602

INVENTORIES (Tables)

INVENTORIES (Tables)	12 Months Ended
	Dec. 31, 2021
INVENTORIES
Schedule of components of inventories	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, ​ December 31, ​ 2021 2020 Parts and raw materials ​ $ 261,365 ​ $ 141,337 Work in process ​ 24,222 ​ 13,702 Finished goods ​ 52,823 ​ 66,307 Total ​ $ 338,410 ​ $ 221,346

PROPERTY AND EQUIPMENT, NET (Ta

PROPERTY AND EQUIPMENT, NET (Tables)	12 Months Ended
	Dec. 31, 2021
PROPERTY AND EQUIPMENT, NET
Schedule of property and equipment, net	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Estimated Useful ​ December 31, ​ December 31, ​ Life (in years) 2021 2020 Buildings ​ 25 ​ $ 1,625 ​ $ 1,776 Machinery and equipment ​ 5 to 8 ​ 133,010 ​ 115,404 Computer equipment, furniture, fixtures, and vehicles ​ 3 to 5 ​ 33,490 ​ 31,237 Leasehold improvements ​ 2 to 10 ​ 48,370 ​ 42,984 Construction in process ​ ​ ​ 5,914 ​ 3,693 ​ ​ ​ ​ 222,409 ​ 195,094 Less: Accumulated depreciation ​ ​ ​ (107,579) ​ (80,363) Property and equipment, net ​ ​ ​ $ 114,830 ​ $ 114,731 ​
Schedule of depreciation expense recorded in continuing operations	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Years Ended December 31, ​ 2021 2020 2019 Depreciation expense $ 30,833 ​ $ 27,641 ​ $ 13,979

GOODWILL (Tables)

GOODWILL (Tables)	12 Months Ended
	Dec. 31, 2021
GOODWILL AND INTANGIBLE ASSETS
Schedule of changes in goodwill	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, ​ December 31, ​ 2021 2020 Balance at beginning of period ​ $ 209,983 ​ $ 202,932 Measurement period adjustments to purchase price allocations ​ ​ (1,426) ​ ​ 1,957 Additions from acquisition ​ ​ 5,877 ​ ​ 1,749 Foreign currency translation ​ ​ (2,244) ​ ​ 3,345 Balance at end of period $ 212,190 ​ $ 209,983

INTANGIBLE ASSETS (Tables)

INTANGIBLE ASSETS (Tables)	12 Months Ended
	Dec. 31, 2021
GOODWILL AND INTANGIBLE ASSETS
Schedule of intangible assets	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, 2021 ​ Gross Carrying Accumulated Net Carrying ​ ​ Amount ​ Amortization ​ Amount Technology ​ $ 91,461 ​ $ (35,854) ​ $ 55,607 Customer relationships ​ 118,706 ​ ​ (34,187) ​ 84,519 Trademarks and other ​ 27,244 ​ ​ (7,964) ​ 19,280 Total ​ $ 237,411 ​ $ (78,005) ​ $ 159,406 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, 2020 ​ Gross Carrying Accumulated Net Carrying ​ ​ Amount ​ Amortization ​ Amount Technology ​ $ 85,075 ​ $ (24,999) ​ $ 60,076 Customer relationships ​ 114,171 ​ (26,880) ​ 87,291 Trademarks and other ​ 27,021 ​ (5,449) ​ 21,572 Total ​ $ 226,267 ​ $ (57,328) ​ $ 168,939
Schedule of amortization expense related to intangible assets	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Years Ended December 31, ​ 2021 2020 2019 Amortization expense ​ $ 22,060 ​ $ 20,129 ​ $ 12,168
Schedule of estimated amortization expense related to intangible assets	​ ​ ​ ​ ​ Year Ending December 31, ​ ​ 2022 ​ 22,025 2023 ​ 22,007 2024 ​ 19,148 2025 ​ 14,653 2026 ​ ​ 12,937 Thereafter ​ 68,636 Total ​ $ 159,406

RESTRUCTURING COSTS (Tables)

RESTRUCTURING COSTS (Tables)	12 Months Ended
	Dec. 31, 2021
RESTRUCTURING COSTS
Schedule of restructuring charges	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Years Ended December 31, ​ ​ 2021 2020 2019 Severance and related charges $ 3,467 ​ $ 9,632 ​ $ 3,042 Facility relocation and closure charges ​ 1,285 ​ 3,534 ​ 1,996 Total restructuring charges ​ $ 4,752 ​ $ 13,166 ​ $ 5,038 ​ ​ ​ ​ ​ ​ ​ Cumulative Cost ​ ​ Through ​ ​ December 31, ​ ​ 2021 Severance and related charges $ 20,380 Facility relocation and closure charges ​ ​ 6,815 Total restructuring charges ​ $ 27,195
Schedule of restructuring liabilities	​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, ​ December 31, ​ ​ 2021 2020 Balance at beginning of period $ 10,641 ​ $ 2,172 Costs incurred and charged to expense ​ ​ 4,752 ​ ​ 13,166 Costs paid or otherwise settled ​ ​ (6,127) ​ ​ (4,714) Effects of changes in exchange rate ​ ​ (3) ​ ​ 17 Balance at end of period ​ $ 9,263 ​ $ 10,641

WARRANTIES (Tables)

WARRANTIES (Tables)	12 Months Ended
	Dec. 31, 2021
WARRANTIES
Schedule of changes in accrued product warranties	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Years Ended December 31, ​ 2021 2020 Balance at beginning of period ​ $ 4,780 ​ $ 6,413 Warranty acquired in business combinations ​ ​ — ​ ​ 15 Increases to accruals ​ 3,165 ​ 2,996 Warranty expenditures ​ (4,587) ​ (4,688) Effect of changes in exchange rates ​ (8) ​ 44 Balance at end of period ​ $ 3,350 ​ $ 4,780

LEASES (Tables)

LEASES (Tables)	12 Months Ended
	Dec. 31, 2021
LEASES
Components of operating lease cost	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Years Ended December 31, ​ 2021 2020 ​ 2019 Operating lease cost ​ $ 23,443 ​ $ 22,920 ​ $ 11,052 Short-term and variable lease cost ​ ​ 2,555 ​ ​ 1,895 ​ ​ 4,726 Total operating lease cost ​ $ 25,998 ​ $ 24,815 ​ $ 15,778
Schedule of maturities of operating lease liabilities	​ ​ ​ ​ ​ Year Ending December 31, ​ ​ 2022 ​ $ 20,416 2023 ​ 17,230 2024 ​ 14,812 2025 ​ ​ 12,426 2026 ​ ​ 11,079 Thereafter ​ ​ 65,785 Total lease payments ​ ​ 141,748 Less: Interest ​ ​ (30,725) Present value of lease liabilities ​ $ 111,023
Schedule of other information related to leases	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Year Ended December 31, ​ ​ ​ 2021 2020 ​ Weighted average remaining lease term (in years) ​ ​ 9.81 ​ ​ 10.65 ​ Weighted average discount rate ​ ​ 4.51 % ​ 4.63 % ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Year Ended December 31, ​ 2021 2020 ​ 2019 Cash paid for operating leases ​ $ 23,668 ​ $ 21,877 ​ $ 12,101 Right-of-use assets obtained in exchange for operating lease liabilities ​ $ 16,399 ​ $ 33,741 ​ $ 84,551

EMPLOYEE RETIREMENT PLANS AND_2

EMPLOYEE RETIREMENT PLANS AND POSTRETIREMENT BENEFITS (Tables)	12 Months Ended
	Dec. 31, 2021
EMPLOYEE RETIREMENT PLANS AND POSTRETIREMENT BENEFITS
Changes in projected benefit obligations and plan assets	Our projected benefit obligation and plan assets for defined benefit pension plans and the related assumptions used to determine the related liabilities are as follows: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Years Ended December 31, ​ 2021 2020 Projected benefit obligation, beginning of year ​ $ 97,740 ​ $ 83,262 Service cost ​ 1,282 ​ 1,068 Interest cost ​ 1,452 ​ 1,716 Actuarial (gain) loss ​ (8,682) ​ 7,591 Benefits paid ​ (2,010) ​ (1,199) Translation adjustment ​ (4,006) ​ 5,302 Projected benefit obligation, end of year ​ $ 85,776 ​ $ 97,740 ​ ​ ​ ​ ​ ​ ​ Fair value of plan assets, beginning of year ​ $ 17,293 ​ $ 14,903 Actual return on plan assets ​ 641 ​ 682 Contributions ​ 1,775 ​ 1,827 Benefits paid ​ (1,112) ​ (993) Actuarial gain ​ 71 ​ 180 Translation adjustment ​ (147) ​ 694 Fair value of plan assets, end of year ​ $ 18,521 ​ $ 17,293 Funded status of plan ​ $ (67,255) ​ $ (80,447)
Schedule of net periodic pension benefit costs	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Years Ended December 31, ​ 2021 2020 2019 Service cost ​ $ 1,282 ​ $ 1,068 ​ $ 272 Interest cost ​ ​ 1,452 ​ ​ 1,716 ​ ​ 1,211 Expected return on plan assets ​ (642) ​ (683) ​ (615) Amortization of actuarial gains and losses ​ 820 ​ 459 ​ 411 Net periodic pension cost ​ $ 2,912 ​ $ 2,560 ​ $ 1,279
Schedule of assumptions used in determination of net period pension cost	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Years Ended December 31, ​ 2021 2020 2019 Discount rate 1.6 % 1.8 % 2.7 % Expected long-term return on plan assets 3.2 % 3.7 % 4.6 %
Schedule of fair value qualified pension plan assets	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, 2021 ​ Level 1 Level 2 Level 3 Total Diversified Growth Fund ​ $ — ​ $ 12,249 ​ $ — ​ $ 12,249 Corporate Bonds ​ — ​ ​ 4,640 ​ ​ — ​ ​ 4,640 Insurance Contracts ​ ​ — ​ ​ — ​ ​ 984 ​ ​ 984 Cash ​ 648 ​ ​ — ​ ​ — ​ ​ 648 Total ​ $ 648 ​ $ 16,889 ​ $ 984 ​ $ 18,521 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, 2020 ​ Level 1 Level 2 Level 3 Total Multi-Asset Fund ​ $ — ​ $ 5,149 ​ $ — ​ $ 5,149 Diversified Growth Fund ​ — ​ 5,134 ​ — ​ 5,134 Corporate Bonds ​ — ​ 4,906 ​ — ​ 4,906 Insurance Contracts ​ ​ — ​ — ​ 1,109 ​ 1,109 Cash ​ 995 ​ — ​ — ​ 995 Total ​ $ 995 ​ $ 15,189 ​ $ 1,109 ​ $ 17,293
Schedule of expected future benefit payments under defined benefit pension plans	​ ​ ​ ​ ​ Year Ending December 31, ​ ​ 2022 ​ $ 1,778 2023 ​ ​ 2,068 2024 ​ ​ 2,847 2025 ​ ​ 2,299 2026 ​ ​ 5,395 2027 to 2031 ​ ​ 18,739

STOCK-BASED COMPENSATION (Table

STOCK-BASED COMPENSATION (Tables)	12 Months Ended
	Dec. 31, 2021
Schedule of stock-based compensation	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Years Ended December 31, ​ 2021 2020 2019 Equity classified awards ​ $ 15,428 ​ $ 12,272 ​ $ 7,327 Liability classified awards ​ ​ 311 ​ ​ — ​ ​ — Stock-based compensation expense ​ $ 15,739 ​ $ 12,272 ​ $ 7,327
Schedule of changes in unvested RSUs	​ ​ ​ ​ ​ ​ ​ ​ ​ Year Ended December 31, 2021 ​ ​ Weighted- ​ ​ ​ ​ Average ​ ​ Number of ​ Grant Date ​ ​ RSUs ​ Fair Value RSUs outstanding at beginning of period 608 ​ $ 58.15 RSUs granted 406 ​ $ 94.60 RSUs vested (178) ​ $ 62.82 RSUs forfeited (209) ​ $ 70.34 RSUs outstanding at end of period 627 ​ $ 76.37
Summary of changes in stock options	Changes in our stock options were as follows: ​ ​ ​ ​ ​ ​ ​ ​ ​ Year Ended December 31, 2021 ​ ​ Weighted- ​ ​ ​ ​ Average ​ ​ Number of ​ Exercise Price ​ ​ Options ​ per Share Options outstanding at beginning of period 147 ​ $ 23.63 Options exercised (35) ​ $ 21.10 Options outstanding at end of period 112 ​ $ 24.41
Schedule of shares authorized under stock option plans, by exercise price range	The following table summarizes information about the stock options outstanding on December 31, 2021: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Options Outstanding and Exercisable ​ ​ Number ​ Weighted-Average ​ Weighted- ​ ​ Outstanding ​ Remaining ​ Average Range of Exercise Prices (In 000's) Contractual Life Exercise Price $18.77 28 2.75 years ​ $ 18.77 $26.32 84 3.10 years ​ $ 26.32 $18.77 to $26.32 112 3.01 years ​ $ 24.41
Employee Stock [Member]
Schedule of stock-based compensation	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Years Ended December 31, ​ 2021 2020 2019 Stock-based compensation expense related to the ESPP ​ $ 1,114 ​ $ 856 ​ $ 475 ​
Schedule of valuation assumptions	The fair value of each purchase right granted under the ESPP was estimated on the date of grant using the Black-Scholes-Merton option pricing model with the following assumptions: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Years Ended December 31, ​ ​ 2021 2020 2019 Risk-free interest rates 0.04% - 0.10 % 0.10% - 0.18% % 1.62% - 2.31 % Expected dividend yield rates — % — % — % Expected term 0.5 years 0.5 years 0.5 years ​ Expected volatility 42.7 % 70.1 % 41.3 %

GEOGRAPHIC AND SIGNIFICANT CU_2

GEOGRAPHIC AND SIGNIFICANT CUSTOMER INFORMATION (Tables)	12 Months Ended
	Dec. 31, 2021
GEOGRAPHIC AND SIGNIFICANT CUSTOMER INFORMATION
Schedules of concentration of risk, by risk factor	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Years Ended December 31, ​ ​ 2021 ​ 2020 ​ 2019 ​ Applied Materials, Inc. ​ $ 296,369 20.4 % ​ $ 248,350 17.5 % ​ $ 164,724 20.9 % Lam Research Corporation ​ 147,385 10.1 % ​ 141,778 10.0 % ​ 88,251 11.2 % ​ The following table summarizes the accounts receivable balances and percentages of the total accounts receivable from customers who individually accounted for 10% or more of accounts receivable: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, ​ December 31, ​ ​ ​ 2021 ​ ​ 2020 ​ Applied Materials, Inc. ​ $ 42,425 17.9 % $ 33,402 14.2 % Nidec Motor Corporation ​ ​ * ​ * % $ 24,344 ​ 10.4 % * Customer’s balance was less than 10% of total
Schedule of long-lived assets by geographic area	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, ​ 2021 2020 United States ​ $ 255,791 ​ $ 253,115 Asia ​ 275,260 ​ 283,549 Europe ​ 57,144 ​ 60,847 Total ​ $ 588,195 ​ $ 597,511

CREDIT FACILITY (Tables)

CREDIT FACILITY (Tables)	12 Months Ended
	Dec. 31, 2021
CREDIT FACILITY
Schedule of borrowings under credit facility	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, 2021 ​ ​ Balance Interest Rate Unused Line Fee Term Loan Facility subject to a fixed interest rate ​ $ 255,719 ​ 1.271% ​ — Term Loan Facility subject to a variable interest rate ​ ​ 139,281 ​ 0.890% ​ — Revolving Facility subject to a variable interest rate ​ ​ — ​ 0.890% ​ 0.10% Total borrowings under the Credit Agreement ​ $ 395,000 ​ ​ ​ ​
Schedule of debt obligation	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, ​ December 31, ​ 2021 2020 Term Loan Facility ​ $ 395,000 ​ $ 323,750 Less: debt issuance costs ​ ​ (2,267) ​ ​ (1,704) Total debt ​ ​ 392,733 ​ ​ 322,046 Less current portion of long-term debt ​ ​ (20,000) ​ ​ (17,500) Total long-term debt ​ $ 372,733 ​ $ 304,546
Schedule of contractual maturities of debt obligations	​ ​ ​ ​ ​ Year Ending December 31, ​ 2022 ​ $ 20,000 2023 ​ ​ 20,000 2024 ​ ​ 20,000 2025 ​ ​ 20,000 2026 ​ ​ 315,000 Total ​ $ 395,000
Schedule of interest expense and unused line of credit fees	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Years Ended December 31, ​ 2021 2020 2019 Interest expense ​ $ 3,969 ​ $ 5,080 ​ $ 2,994 Amortization of debt issuance costs ​ ​ 822 ​ ​ 519 ​ ​ 186 Unused line of credit fees and other ​ ​ 168 ​ ​ 153 ​ ​ 236 Total interest expense ​ $ 4,959 ​ $ 5,752 ​ $ 3,416

OPERATIONS AND SUMMARY OF SIG_3

OPERATIONS AND SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES AND ESTIMATES - Revenue Recognition and Warrant Costs (Details)	12 Months Ended
	Dec. 31, 2021country
Worldwide support organization maintained in number of countries	10
Precision Power Products [Member] | Minimum [Member]
Warranty period	12 months
Precision Power Products [Member] | Maximum [Member]
Warranty period	24 months
Inverter Products [Member] | Minimum [Member]
Warranty period	5 years
Inverter Products [Member] | Maximum [Member]
Warranty period	10 years
Buildings [Member] | Inverter Products [Member] | Maximum [Member]
Additional warranty period	20 years

ACQUISITIONS - Intangible Asset

ACQUISITIONS - Intangible Assets Acquired (Details) - Technology - USD ($) $ in Millions	1 Months Ended	12 Months Ended
	Jan. 31, 2021	Dec. 31, 2021
Acquired Finite-Lived Intangible Assets [Line Items]
Intangible asset acquisition, transaction cost incurred		$ 6.1
Intangible asset acquisition, contingent consideration		$ 0.4
Useful Life	5 years

ACQUISITIONS - Consideration Tr

ACQUISITIONS - Consideration Transferred (Details) - USD ($) $ in Thousands	Jun. 01, 2021	Dec. 31, 2021	Dec. 31, 2020
TEGAM, Inc. [Member]
Business Acquisition [Line Items]
Cash paid for acquisition	$ 15,430
Holdback	1,800
Total fair value of consideration transferred	17,230
Less cash acquired	(177)
Total purchase price	$ 17,053
Acquired percentage	100.00%
Versatile Power, Inc. [Member]
Business Acquisition [Line Items]
Cash paid for acquisition		$ 4,654
Holdback		950
Total fair value of consideration transferred		5,604
Less cash acquired		(245)
Total purchase price		$ 5,359	$ 5,359
Acquired percentage			100.00%

ACQUISITIONS - Assets Acquired

ACQUISITIONS - Assets Acquired and Liabilities Assumed (Details) - USD ($) $ in Thousands	Dec. 31, 2021	Jun. 01, 2021	Dec. 31, 2020
TEGAM, Inc. [Member]
Business Acquisition [Line Items]
Current assets and liabilities, net		$ 3,536
Property and equipment		734
Operating lease right-of-use assets		425
Intangible assets		6,900
Goodwill (deductible for tax purposes)		5,877
Other non-current assets		31
Total assets acquired		17,503
Other non-current liabilities		25
Operating lease liability		425
Total liabilities assumed		450
Total fair value of net assets acquired		$ 17,053
Versatile Power, Inc. [Member]
Business Acquisition [Line Items]
Current assets and liabilities, net			$ 1,021
Property and equipment			35
Operating lease right-of-use assets			463
Intangible assets			4,000
Goodwill (deductible for tax purposes)			323
Total assets acquired			5,842
Other non-current liabilities			20
Operating lease liability			463
Total liabilities assumed			483
Total fair value of net assets acquired	$ 5,359		$ 5,359

ACQUISITIONS - Schedule of Inta

ACQUISITIONS - Schedule of Intangible Assets Acquired, Amortization Method, and Estimated Useful Lives (Details) - USD ($) $ in Thousands	Jun. 01, 2021	Jan. 31, 2021	Dec. 31, 2020
TEGAM, Inc. [Member]
Business Acquisition [Line Items]
Amortizable intangible assets:	$ 6,900
Versatile Power, Inc. [Member]
Business Acquisition [Line Items]
Amortizable intangible assets:			$ 4,000
Technology
Business Acquisition [Line Items]
Useful Life		5 years
Technology | TEGAM, Inc. [Member]
Business Acquisition [Line Items]
Amortizable intangible assets:	$ 1,100
Useful Life	5 years
Technology | Versatile Power, Inc. [Member]
Business Acquisition [Line Items]
Amortizable intangible assets:			$ 400
Useful Life			5 years
Customer Relationships [Member] | TEGAM, Inc. [Member]
Business Acquisition [Line Items]
Amortizable intangible assets:	$ 5,500
Useful Life	15 years
Customer Relationships [Member] | Versatile Power, Inc. [Member]
Business Acquisition [Line Items]
Amortizable intangible assets:			$ 3,600
Useful Life			15 years
Trade Names [Member] | TEGAM, Inc. [Member]
Business Acquisition [Line Items]
Amortizable intangible assets:	$ 300
Useful Life	5 years

ACQUISITIONS - Operating Result

ACQUISITIONS - Operating Results in Consolidated Financial Statements (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
ACQUISITIONS
Sales, net	$ 1,455,954	$ 1,415,826	$ 788,948
Net Income (Loss)	$ 134,780	$ 134,730	$ 64,975

REVENUE - Nature of Goods and S

REVENUE - Nature of Goods and Services (Details) - USD ($) $ in Thousands	Dec. 31, 2021	Dec. 31, 2020
REVENUE
Deferred revenue	$ 7,067	$ 8,671

REVENUE - Revenue by Product Li

REVENUE - Revenue by Product Line (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	$ 1,455,954	$ 1,415,826	$ 788,948
Sales to external customers	100.00%	100.00%	100.00%
UNITED STATES
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	$ 561,312	$ 530,965	$ 321,869
Sales to external customers	38.50%	37.50%	40.80%
North America (excluding U.S.) [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	$ 104,167	$ 156,856	$ 51,765
Sales to external customers	7.20%	11.10%	6.60%
Asia [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	$ 597,830	$ 606,893	$ 295,155
Sales to external customers	41.10%	42.90%	37.40%
Europe [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	$ 179,056	$ 117,989	$ 119,427
Sales to external customers	12.30%	8.30%	15.10%
Other countries [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	$ 13,589	$ 3,123	$ 732
Sales to external customers	0.90%	0.20%	0.10%
Semiconductor Equipment [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	$ 710,174	$ 611,864	$ 403,018
Industrial and Medical [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	341,176	313,646	245,992
Data Center Computing [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	270,924	322,539	91,438
Telecom and Networking [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	133,680	167,777	48,500
Product [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	1,318,213	1,296,867	678,061
Service [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	$ 137,741	$ 118,959	$ 110,887

DISPOSED AND DISCONTINUED OPE_2

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] - USD ($)	11 Months Ended	12 Months Ended
	Mar. 31, 2020	Dec. 31, 2019	May 31, 2019
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Consideration from disposed operations			$ 1
Loan	$ 5,300,000
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

INCOME TAXES - Narrative (Detai

INCOME TAXES - Narrative (Details)	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
INCOME TAXES
Effective Income Tax Rate Reconciliation, at Federal Statutory Income Tax Rate, Percent	21.00%	21.00%	21.00%

INCOME TAXES - Earnings Before

INCOME TAXES - Earnings Before Income Taxes by Geographical Area (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
INCOME TAXES
Domestic	$ 24,541	$ 17,526	$ (20,597)
Foreign	124,170	140,621	87,791
Income from continuing operations, before income taxes	$ 148,711	$ 158,147	$ 67,194

INCOME TAXES - Components of In

INCOME TAXES - Components of Income Tax Expense (Benefit) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Current
Federal	$ (2,468)	$ 5,475	$ (9,627)
State	929	1,927	882
Foreign	14,217	16,216	18,429
Total current provision	12,678	23,618	9,684
Deferred
Federal	762	(312)	3,822
State	(200)	1,270	(178)
Foreign	764	(1,580)	(2,629)
Total deferred provision (benefit)	1,326	(622)	1,015
Total provision for income taxes	$ 14,004	$ 22,996	$ 10,699

INCOME TAXES - Reconciliation o

INCOME TAXES - Reconciliation of Effective Tax Rate (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
INCOME TAXES
Income taxes per federal statutory rate	$ 31,229	$ 33,211	$ 14,111
State income taxes, net of federal deduction	534	2,793	10
U.S. tax on foreign operations	5,786	9,666	5,805
Foreign derived intangible income deduction	(3,927)	(4,070)
Tax effect of foreign operations	(11,520)	(20,527)	(13,086)
Uncertain tax positions	(6,899)	(3,215)	(4,487)
Audit settlements	7,764
Unremitted earnings	261	(567)	1,624
Tax credits	(6,149)	(2,292)	(2,088)
Change in valuation allowance	(73)	(1,175)	7,222
Withholding taxes	756	4,265	6,500
Executive compensation limitation	1,926	1,070	356
Other permanent items, net	(5,684)	3,837	(5,268)
Total provision for income taxes	$ 14,004	$ 22,996	$ 10,699

INCOME TAXES - Schedule of Defe

INCOME TAXES - Schedule of Deferred Tax Assets and Liabilities (Details) - USD ($) $ in Thousands	Dec. 31, 2021	Dec. 31, 2020
Deferred tax assets
Stock-based compensation	$ 2,528	$ 2,130
Net operating loss and tax credit carryforwards	54,210	57,590
Interest expense limitation	7,344	7,344
Pension obligation	10,778	14,297
Excess and obsolete inventory	3,325	3,722
Accrued restructuring	2,223	2,468
Deferred revenue	4,195	3,048
Employee bonuses and commissions	3,861	5,388
Amortization	26,358	28,786
Operating lease liabilities	19,405	20,267
Other	8,017	8,925
Deferred tax assets	142,244	153,965
Less: Valuation allowance	(42,051)	(46,702)
Net deferred tax assets	100,193	107,263
Deferred tax liabilities
Depreciation and amortization	37,515	40,266
Unremitted earnings	4,435	4,173
Operating lease right-of-use assets	17,558	18,731
Other	3,364	3,380
Deferred tax liabilities	62,872	66,550
Net deferred tax assets	37,321	40,713
Deferred income tax assets	47,242	50,801
Deferred income tax liabilities	$ 9,921	$ 10,088

INCOME TAXES - Valuation Allowa

INCOME TAXES - Valuation Allowances (Details) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
Operating Loss Carryforwards [Line Items]
Deferred Tax Assets, Valuation Allowance	$ 42,051	$ 46,702
Capital loss carryforwards	800
Interest expense limitation carryforwards	30,500
Federal net operating loss carry forwards, have no expiration period	8,000
Tax holiday, taxes decrease	$ 13,300	$ 13,000
Income Tax Holiday, Income Tax Benefits Per Share	$ 0.35	$ 0.34
Decrease in valuation allowance	$ 4,700
Undistributed earnings of foreign subsidiaries	32,400
Domestic Tax Authority [Member]
Operating Loss Carryforwards [Line Items]
Deferred Tax Assets, Valuation Allowance	4,000
Operating Loss Carryforwards	56,900
Tax Credit Carryforward, Amount	1,500
Foreign Tax Authority [Member]
Operating Loss Carryforwards [Line Items]
Deferred Tax Assets, Valuation Allowance	38,000
Operating Loss Carryforwards	129,000
State Taxing Authority [Member]
Operating Loss Carryforwards [Line Items]
Operating Loss Carryforwards	117,100
Tax Credit Carryforward, Amount	$ 1,700

INCOME TAXES - Reconciliation_2

INCOME TAXES - Reconciliation of Tax Contingencies (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Income Tax Contingency [Line Items]
Balance at beginning of period	$ 9,673	$ 13,009	$ 13,162
Additions based on tax positions taken during a prior period	963	219	484
Additions based on tax positions taken during the current period	566
Reductions based on tax positions taken during a prior period			(4,295)
Reductions related to a lapse of applicable statute of limitations	(4,575)	(3,555)	(821)
Reductions related to a settlement with taxing authorities	(1,114)
Balance at end of period	$ 5,513	$ 9,673	13,009
Acquisitions [Member]
Income Tax Contingency [Line Items]
Additions based on tax positions taken during a prior period			$ 4,479

INCOME TAXES - Unrecognized Tax

INCOME TAXES - Unrecognized Tax Benefits (Details) - USD ($) $ in Thousands	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
INCOME TAXES
Unrecognized Tax Benefits	$ 5,513	$ 9,673	$ 13,009	$ 13,162
Unrecognized Tax Benefits, Income Tax Penalties and Interest Accrued	$ 400	$ 3,200

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	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
EARNINGS PER SHARE
Income from continuing operations	$ 134,707	$ 135,151	$ 56,495
Less: income from continuing operations attributable to noncontrolling interest	44	55	34
Income from continuing operations attributable to Advanced Energy Industries, Inc.	$ 134,663	$ 135,096	$ 56,461
Basic weighted-average common shares outstanding	38,143	38,314	38,281
Assumed exercise of dilutive stock options and restricted stock units	212	228	214
Diluted weighted-average common shares outstanding	38,355	38,542	38,495
Continuing Operations:
Basic earnings per share (in dollars per share)	$ 3.53	$ 3.53	$ 1.47
Diluted earnings per share (in dollars per share)	$ 3.51	$ 3.51	$ 1.47

EARNINGS PER SHARE - Share Repu

EARNINGS PER SHARE - Share Repurchase (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Jul. 29, 2021
EARNINGS PER SHARE
Amount paid to repurchase shares	$ 78,125	$ 11,630
Number of shares repurchased	901	244
Average repurchase price per share	$ 86.76	$ 47.75
Remaining authorized by Board of Directors for future repurchases as of period end	$ 128,377	$ 38,369
Shares repurchased from related parties	0
Stock repurchase plan authorized amount			$ 200,000

FAIR VALUE MEASUREMENTS - Asset

FAIR VALUE MEASUREMENTS - Assets and Liabilities Measured at Fair Value (Details) - Fair Value, Measurements, Recurring [Member] - USD ($) $ in Thousands	Dec. 31, 2021	Dec. 31, 2020
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total assets	$ 5,035	$ 2,654
Total liabilities	1,738	7,760
Contingent Consideration [Member] | Other Current Liabilities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total liabilities	1,738	2,009
Contingent Consideration [Member] | Other Long-Term Liabilities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total liabilities		2,940
Interest Rate Swaps [Member] | Other Long-Term Liabilities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total liabilities		2,811
Certificates of Deposit [Member] | Marketable Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total assets	2,296	2,654
Interest Rate Swaps [Member] | Deposits and Other Assets [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total assets	2,739
Fair Value, Inputs, Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total assets	5,035	2,654
Total liabilities		2,811
Fair Value, Inputs, Level 2 [Member] | Interest Rate Swaps [Member] | Other Long-Term Liabilities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total liabilities		2,811
Fair Value, Inputs, Level 2 [Member] | Certificates of Deposit [Member] | Marketable Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total assets	2,296	2,654
Fair Value, Inputs, Level 2 [Member] | Interest Rate Swaps [Member] | Deposits and Other Assets [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total assets	2,739
Fair Value, Inputs, Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total liabilities	1,738	4,949
Fair Value, Inputs, Level 3 [Member] | Contingent Consideration [Member] | Other Current Liabilities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total liabilities	$ 1,738	2,009
Fair Value, Inputs, Level 3 [Member] | Contingent Consideration [Member] | Other Long-Term Liabilities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total liabilities		$ 2,940

FAIR VALUE MEASUREMENTS (Detail

FAIR VALUE MEASUREMENTS (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
FAIR VALUE MEASUREMENTS
Transfer into Level 3, Liabilities	$ 0	$ 0
Transfer from Level 3, Liabilities	0	0
Transfer into Level 3, Assets	0	0
Transfer from Level 3, Assets	$ 0	$ 0

DERIVATIVE FINANCIAL INSTRUME_3

DERIVATIVE FINANCIAL INSTRUMENTS (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2021USD ($)	Dec. 31, 2020USD ($)
Derivative Instruments, Gain (Loss) [Line Items]
Annual interest (as a percent)	1.271%
Average fixed rate	0.521%
Cash Flow Hedge [Member] | Designated as Hedging Instrument [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Basis points at current leverage ratios	75
Foreign Exchange Forward [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Derivative, notional amount	$ 0	$ 0

DERIVATIVE FINANCIAL INSTRUME_4

DERIVATIVE FINANCIAL INSTRUMENTS - Qualified Hedging Instruments (Details) - Interest Rate Swaps [Member] - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
Derivative [Line Items]
Derivative, notional amount	$ 255,719	$ 273,219
Balances recorded in Accumulated other comprehensive loss	$ 2,107	$ (2,139)

ACCOUNTS AND OTHER RECEIVABLE_3

ACCOUNTS AND OTHER RECEIVABLE, NET (Details) - USD ($) $ in Thousands	Dec. 31, 2021	Dec. 31, 2020
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total receivables, net	$ 237,227	$ 235,178
Amounts billed, net
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total receivables, net	217,549	213,560
Unbilled receivables
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total receivables, net	$ 19,678	$ 21,618

ACCOUNTS AND OTHER RECEIVABLE_4

ACCOUNTS AND OTHER RECEIVABLE, NET - Expected Credit Losses - (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
ACCOUNTS AND OTHER RECEIVABLE, NET
Balance as of beginning of period	$ 7,602	$ 7,745
Additions	135	368
Deductions - write-offs, net of recoveries	(687)	(511)
Foreign currency translation	(18)
Other	(1,248)
Balance as of end of period	$ 5,784	$ 7,602

INVENTORIES (Details)

INVENTORIES (Details) - USD ($) $ in Thousands	Dec. 31, 2021	Dec. 31, 2020
INVENTORIES
Parts and raw materials	$ 261,365	$ 141,337
Work in process	24,222	13,702
Finished goods	52,823	66,307
Total	$ 338,410	$ 221,346

PROPERTY AND EQUIPMENT, NET (De

PROPERTY AND EQUIPMENT, NET (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	$ 222,409	$ 195,094
Less: Accumulated depreciation	(107,579)	(80,363)
Property and equipment, net	$ 114,830	114,731
Buildings [Member]
Property, Plant and Equipment [Line Items]
Estimated Useful Life (in years)	25 years
Property, plant and equipment, gross	$ 1,625	1,776
Machinery and equipment [Member]
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	$ 133,010	115,404
Machinery and equipment [Member] | Minimum [Member]
Property, Plant and Equipment [Line Items]
Estimated Useful Life (in years)	5 years
Machinery and equipment [Member] | Maximum [Member]
Property, Plant and Equipment [Line Items]
Estimated Useful Life (in years)	8 years
Computer equipment, furniture, fixtures, and vehicles [Member]
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	$ 33,490	31,237
Computer equipment, furniture, fixtures, and vehicles [Member] | Minimum [Member]
Property, Plant and Equipment [Line Items]
Estimated Useful Life (in years)	3 years
Computer equipment, furniture, fixtures, and vehicles [Member] | Maximum [Member]
Property, Plant and Equipment [Line Items]
Estimated Useful Life (in years)	5 years
Leasehold improvements [Member]
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	$ 48,370	42,984
Leasehold improvements [Member] | Minimum [Member]
Property, Plant and Equipment [Line Items]
Estimated Useful Life (in years)	2 years
Leasehold improvements [Member] | Maximum [Member]
Property, Plant and Equipment [Line Items]
Estimated Useful Life (in years)	10 years
Construction in process [Member]
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	$ 5,914	$ 3,693

PROPERTY AND EQUIPMENT, NET - D

PROPERTY AND EQUIPMENT, NET - Depreciation Expense Recorded in Continuing Operations (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
PROPERTY AND EQUIPMENT, NET
Depreciation expense	$ 30,833	$ 27,641	$ 13,979

GOODWILL - Changes in Goodwill

GOODWILL - Changes in Goodwill (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
GOODWILL AND INTANGIBLE ASSETS
Balance at beginning of period	$ 209,983	$ 202,932
Measurement period adjustments to purchase price allocations	(1,426)	1,957
Additions from acquisition	5,877	1,749
Foreign currency translation	(2,244)	3,345
Balance at end of period	$ 212,190	$ 209,983

INTANGIBLE ASSETS (Details)

INTANGIBLE ASSETS (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
Finite-Lived Intangible Assets [Line Items]
Finite-Lived Intangible Assets, Gross	$ 237,411	$ 226,267
Finite-Lived Intangible Assets, Accumulated Amortization	(78,005)	(57,328)
Finite-lived intangible assets, net	$ 159,406	168,939
Amortization of weighted average remaining useful life	9 years 9 months 18 days
Technology
Finite-Lived Intangible Assets [Line Items]
Finite-Lived Intangible Assets, Gross	$ 91,461	85,075
Finite-Lived Intangible Assets, Accumulated Amortization	(35,854)	(24,999)
Finite-lived intangible assets, net	55,607	60,076
Customer Relationships [Member]
Finite-Lived Intangible Assets [Line Items]
Finite-Lived Intangible Assets, Gross	118,706	114,171
Finite-Lived Intangible Assets, Accumulated Amortization	(34,187)	(26,880)
Finite-lived intangible assets, net	84,519	87,291
Trademarks and other [Member]
Finite-Lived Intangible Assets [Line Items]
Finite-Lived Intangible Assets, Gross	27,244	27,021
Finite-Lived Intangible Assets, Accumulated Amortization	(7,964)	(5,449)
Finite-lived intangible assets, net	$ 19,280	$ 21,572

INTANGIBLE ASSETS - Amortizatio

INTANGIBLE ASSETS - Amortization Expense Related to Intangible Assets (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
GOODWILL AND INTANGIBLE ASSETS
Amortization expense	$ 22,060	$ 20,129	$ 12,168

INTANGIBLE ASSETS - Estimated A

INTANGIBLE ASSETS - Estimated Amortization Expense (Details) - USD ($) $ in Thousands	Dec. 31, 2021	Dec. 31, 2020
GOODWILL AND INTANGIBLE ASSETS
2022	$ 22,025
2023	22,007
2024	19,148
2025	14,653
2026	12,937
Thereafter	68,636
Finite-lived intangible assets, net	$ 159,406	$ 168,939

RESTRUCTURING COSTS - Restructu

RESTRUCTURING COSTS - Restructuring Charges (Details) - USD ($) $ in Thousands	12 Months Ended			48 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2021
Restructuring Cost and Reserve [Line Items]
Restructuring expense	$ 4,752	$ 13,166	$ 5,038	$ 27,195
Severance and related charges
Restructuring Cost and Reserve [Line Items]
Restructuring expense	3,467	9,632	3,042	20,380
Facility relocation and closure charges
Restructuring Cost and Reserve [Line Items]
Restructuring expense	$ 1,285	$ 3,534	$ 1,996	$ 6,815

RESTRUCTURING COSTS - Changes i

RESTRUCTURING COSTS - Changes in Restructuring Liabilities (Details) - USD ($) $ in Thousands	12 Months Ended			48 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2021
Restructuring Reserve [Roll Forward]
Beginning balance	$ 10,641	$ 2,172
Cost incurred and charged to expense	4,752	13,166	$ 5,038	$ 27,195
Cost paid or otherwise settled	(6,127)	(4,714)
Effect of change in exchange rates	(3)	17
Ending balance	$ 9,263	$ 10,641	$ 2,172	$ 9,263

WARRANTIES - Narrative (Details

WARRANTIES - Narrative (Details)	12 Months Ended
	Dec. 31, 2021
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 Product

WARRANTIES - Changes in Product Warranty Obligation (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
Movement in Standard Product Warranty Accrual [Roll Forward]
Balance at beginning of period	$ 4,780	$ 6,413
Warranty acquired in business combinations		15
Increases to accruals	3,165	2,996
Warranty expenditures	(4,587)	(4,688)
Effect of changes in exchange rates	(8)	44
Balance at end of period	$ 3,350	$ 4,780

LEASES - Components of Operatin

LEASES - Components of Operating Lease Cost (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
LEASES
Operating lease cost	$ 23,443	$ 22,920	$ 11,052
Short-term and variable lease cost	2,555	1,895	4,726
Total operating lease cost	$ 25,998	$ 24,815	$ 15,778

LEASES - Maturities of Operatin

LEASES - Maturities of Operating Lease Liabilities (Details) $ in Thousands	Dec. 31, 2021USD ($)
LEASES
2022	$ 20,416
2023	17,230
2024	14,812
2025	12,426
2026	11,079
Thereafter	65,785
Total lease payments	141,748
Less: Interest	(30,725)
Present value of lease liabilities	111,023
Payments for lease agreements that commence in the future	$ 4,300

LEASES - Other lease cost infor

LEASES - Other lease cost information (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
LEASES
Weighted average remaining lease term (in years)	9 years 9 months 21 days	10 years 7 months 24 days
Weighted average discount rate	4.51%	4.63%
Cash paid for operating leases	$ 23,668	$ 21,877	$ 12,101
Right-of-use assets obtained in exchange for operating lease liabilities	$ 16,399	$ 33,741	$ 84,551

EMPLOYEE RETIREMENT PLANS AND_3

EMPLOYEE RETIREMENT PLANS AND POSTRETIREMENT BENEFITS - Defined Contribution Plans (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
EMPLOYEE RETIREMENT PLANS AND POSTRETIREMENT BENEFITS
Matching contributions	50.00%	50.00%	50.00%
Employer Matching Contribution, Percent of Employees' Gross Pay	6.00%	6.00%	6.00%
Defined Contribution Plan, Cost	$ 3.1	$ 2.6	$ 1.6

EMPLOYEE RETIREMENT PLANS AND_4

EMPLOYEE RETIREMENT PLANS AND POSTRETIREMENT BENEFITS - Projected Benefit Obligation and Plan Assets (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Changes in projected benefit obligation
Projected benefit obligation, beginning of year	$ 97,740	$ 83,262
Service cost	1,282	1,068	$ 272
Interest cost	1,452	1,716	1,211
Actuarial (gain) loss	(8,682)	7,591
Benefits paid	(2,010)	(1,199)
Translation adjustment	(4,006)	5,302
Projected benefit obligation, end of year	85,776	97,740	83,262
Changes in fair value of plan assets
Fair value of plan assets, beginning of year	17,293	14,903
Actual return on plan assets	641	682
Contributions	1,775	1,827
Benefits paid	(1,112)	(993)
Actuarial gain	71	180
Translation adjustment	(147)	694
Fair value of plan assets, end of year	18,521	17,293	$ 14,903
Funded status of plan	$ (67,255)	$ (80,447)

EMPLOYEE RETIREMENT PLANS AND_5

EMPLOYEE RETIREMENT PLANS AND POSTRETIREMENT BENEFITS - Net Periodic Pension Benefit Cost (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Net periodic pension benefit cost
Service cost	$ 1,282	$ 1,068	$ 272
Interest cost	1,452	1,716	1,211
Expected return on plan assets	(642)	(683)	(615)
Amortization of actuarial gains and losses	820	459	411
Net periodic pension cost	$ 2,912	$ 2,560	$ 1,279

EMPLOYEE RETIREMENT PLANS AND_6

EMPLOYEE RETIREMENT PLANS AND POSTRETIREMENT BENEFITS - Net Periodic Pension Cost Assumptions (Details)	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Assumptions used in the determination of the net periodic pension cost:
Discount rate	1.60%	1.80%	2.70%
Expected long-term return on plan assets	3.20%	3.70%	4.60%

EMPLOYEE RETIREMENT PLANS AND_7

EMPLOYEE RETIREMENT PLANS AND POSTRETIREMENT BENEFITS - Fair Value of Plan Assets by Category (Details) - USD ($) $ in Thousands	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Defined Benefit Plan Disclosure [Line Items]
Fair value of Plan Assets	$ 18,521	$ 17,293	$ 14,903
Fair Value, Inputs, Level 2 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of Plan Assets	16,889	15,189
Fair Value, Inputs, Level 3 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of Plan Assets	984	1,109
Fair Value, Inputs, Level 1 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of Plan Assets	648	995
Multi-asset Fund [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of Plan Assets		5,149
Multi-asset Fund [Member] | Fair Value, Inputs, Level 2 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of Plan Assets		5,149
Defined Growth Fund [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of Plan Assets	$ 12,249	5,134
Investment percentage within Plan Asset category	66.10%
Defined Growth Fund [Member] | Fair Value, Inputs, Level 2 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of Plan Assets	$ 12,249	5,134
Corporate Debt Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of Plan Assets	$ 4,640	4,906
Investment percentage within Plan Asset category	25.10%
Corporate Debt Securities [Member] | Fair Value, Inputs, Level 2 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of Plan Assets	$ 4,640	4,906
Insurance Contract [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of Plan Assets	$ 984	1,109
Investment percentage within Plan Asset category	5.30%
Insurance Contract [Member] | Fair Value, Inputs, Level 3 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of Plan Assets	$ 984	1,109
Cash [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of Plan Assets	648	995
Cash [Member] | Fair Value, Inputs, Level 1 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of Plan Assets	$ 648	$ 995

EMPLOYEE RETIREMENT PLANS AND_8

EMPLOYEE RETIREMENT PLANS AND POSTRETIREMENT BENEFITS - Expected Future Payments (Details) $ in Thousands	Dec. 31, 2021USD ($)
EMPLOYEE RETIREMENT PLANS AND POSTRETIREMENT BENEFITS
2022	$ 1,778
2023	2,068
2024	2,847
2025	2,299
2026	5,395
2027 to 2031	$ 18,739

STOCK-BASED COMPENSATION - Narr

STOCK-BASED COMPENSATION - Narrative (Details) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2021USD ($)plan$ / sharesshares	Dec. 31, 2020USD ($)	Dec. 31, 2019USD ($)	May 01, 2010shares	Apr. 30, 2010shares
Stock-based incentive compensation plans | plan	2
Shares reserved | shares	3,300,000
Shares available for grant | shares	2,600,000
Awards term	10 years
Estimated Forfeiture rates for Share Based Compensation	8.00%	5.00%	10.00%
Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercises in Period, Total Intrinsic Value	$ 2,600	$ 1,900	$ 1,600
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Intrinsic Value	$ 7,500
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Weighted Average Remaining Contractual Term	3 years
Stock-based compensation expense	$ 15,739	12,272	7,327
2017 OMNIBUS Incentive Plan [Member] [Domain]
Shares available for grant | shares	1,900,000
Restricted Stock Units (RSUs) [Member]
Employee Service Share-based Compensation, Nonvested Awards, Total Compensation Cost Not yet Recognized	$ 21,400
Employee Stock [Member]
Options granted (in shares) | shares	0
Minimum [Member] | Employee Stock [Member]
Vesting period	3 years
Maximum [Member] | Employee Stock [Member]
Vesting period	4 years
Restricted Stock Units (RSUs) [Member]
Vesting period	3 years
Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercises in Period, Total Intrinsic Value	$ 19,200	9,200	8,300
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Outstanding, Weighted Average Remaining Contractual Terms	1 year 1 month 6 days
Share-based Compensation Arrangement by Share-based Payment Award, Options, Grants in Period, Weighted Average Grant Date Fair Value | $ / shares	$ 94.60
Employee Stock [Member]
Employee Service Share-based Compensation, Nonvested Awards, Total Compensation Cost Not yet Recognized	$ 600
Employee Service Share-based Compensation recognized remaining period	5 months
Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Authorized | shares	1,000,000			1,000,000	500,000
Share-based Compensation Arrangement By Share-based Payment Award, Employee Contribution, Amount	$ 5
Stock-based compensation expense	$ 1,114	$ 856	$ 475
Share-based Compensation Arrangement by Share-based Payment Award, Discount from Market Price, Offering Date	85.00%
Share-based Compensation Arrangement by Share-based Payment Award, Discount from Market Price, Purchase Date	85.00%
Employee Stock [Member] | Employee Stock [Member]
Shares available for grant | shares	700,000
Employee Stock [Member] | Maximum [Member]
Share-based Compensation Arrangement By Share-based Payment Award, Employee Contribution, Percent	15.00%

STOCK-BASED COMPENSATION - Stoc

STOCK-BASED COMPENSATION - Stock-Based Compensation (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation expense	$ 15,739	$ 12,272	$ 7,327
Equity classified awards [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation expense	15,428	$ 12,272	$ 7,327
Liability classified awards [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation expense	$ 311

STOCK-BASED COMPENSATION - Chan

STOCK-BASED COMPENSATION - Changes in RSUs (Details) - Restricted Stock Units (RSUs) [Member] shares in Thousands	12 Months Ended
	Dec. 31, 2021$ / sharesshares
Outstanding at the beginning of period | shares	608
Granted | shares	406
Vested | shares	(178)
Forfeited | shares	(209)
Outstanding at the end of period | shares	627
Weighted Average Grant Date Fair Value, Beginning Balance | $ / shares	$ 58.15
Weighted Average Grant Date Fair Value, Granted | $ / shares	94.60
Weighted Average Grant Date Fair Value, Vested | $ / shares	62.82
Weighted Average Grant Date Fair Value, Forfeited | $ / shares	70.34
Weighted Average Grant Date Fair Value, Ending Balance | $ / shares	$ 76.37

STOCK-BASED COMPENSATION - Ch_2

STOCK-BASED COMPENSATION - Changes in Stock Options (Details) - Time Based [Member] shares in Thousands	12 Months Ended
	Dec. 31, 2021$ / sharesshares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Outstanding at beginning of period | shares	147
Exercised | shares	(35)
Outstanding at ending of period | shares	112
Weighted-Average Exercise Price Per Share, Beginning Balance | $ / shares	$ 23.63
Weighted-Average Exercise Price Per Share, Exercised | $ / shares	21.10
Weighted-Average Exercise Price Per Share, End Balance | $ / shares	$ 24.41

STOCK-BASED COMPENSATION - St_2

STOCK-BASED COMPENSATION - Stock Options Outstanding (Details) shares in Thousands	12 Months Ended
	Dec. 31, 2021$ / sharesshares
$18.77
Range of Exercise Prices	$ 18.77
Number Outstanding | shares	28
Weighted-Average Remaining Contractual Life	2 years 9 months
Weighted Average Exercise Price	$ 18.77
$26.32
Range of Exercise Prices	$ 26.32
Number Outstanding | shares	84
Weighted-Average Remaining Contractual Life	3 years 1 month 6 days
Weighted Average Exercise Price	$ 26.32
$18.77 to $26.32
Number Outstanding | shares	112
Weighted-Average Remaining Contractual Life	3 years 3 days
Weighted Average Exercise Price	$ 24.41
Minimum [Member] | $18.77 to $26.32
Range of Exercise Prices, Lower Range Limit	18.77
Maximum [Member] | $18.77 to $26.32
Range of Exercise Prices, Upper Range Limit	$ 26.32

STOCK-BASED COMPENSATION - Comp

STOCK-BASED COMPENSATION - Compensation expense related to ESPP (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Stock-based compensation expense	$ 15,739	$ 12,272	$ 7,327
Employee Stock [Member]
Stock-based compensation expense	$ 1,114	$ 856	$ 475

STOCK-BASED COMPENSATION - Fair

STOCK-BASED COMPENSATION - Fair Value Assumptions (Details) - Employee Stock [Member]	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Expected dividend yield rates	0.00%	0.00%	0.00%
Expected term	6 months	6 months	6 months
Expected volatility	42.70%	70.10%	41.30%
Minimum [Member]
Risk-free interest rates	0.04%	0.10%	1.62%
Maximum [Member]
Risk-free interest rates	0.10%	0.18%	2.31%

GEOGRAPHIC AND SIGNIFICANT CU_3

GEOGRAPHIC AND SIGNIFICANT CUSTOMER INFORMATION (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Revenue, Major Customer [Line Items]
Sales, net	$ 1,455,954	$ 1,415,826	$ 788,948
Product [Member]
Revenue, Major Customer [Line Items]
Sales, net	1,318,213	1,296,867	678,061
Sales Revenue, Net [Member] | Customer Concentration Risk [Member] | Applied Materials, Inc. [Member]
Revenue, Major Customer [Line Items]
Sales, net	$ 296,369	$ 248,350	$ 164,724
Significant concentration risk, 10% or more of total balance	20.40%	17.50%	20.90%
Sales Revenue, Net [Member] | Customer Concentration Risk [Member] | Lam Research Corporation [Member]
Revenue, Major Customer [Line Items]
Sales, net	$ 147,385	$ 141,778	$ 88,251
Significant concentration risk, 10% or more of total balance	10.10%	10.00%	11.20%
Accounts Receivable [Member] | Credit Concentration Risk [Member] | Applied Materials, Inc. [Member]
Revenue, Major Customer [Line Items]
Significant concentration risk, 10% or more of total balance	17.90%	14.20%
Accounts receivable	$ 42,425	$ 33,402
Accounts Receivable [Member] | Credit Concentration Risk [Member] | Nidec Motor Corporation [Member]
Revenue, Major Customer [Line Items]
Significant concentration risk, 10% or more of total balance		10.40%
Accounts receivable		$ 24,344

GEOGRAPHIC AND SIGNIFICANT CU_4

GEOGRAPHIC AND SIGNIFICANT CUSTOMER INFORMATION - Long-lived Assets by Geographic Area (Details) - USD ($) $ in Thousands	Dec. 31, 2021	Dec. 31, 2020
Segment Reporting Information [Line Items]
Long-Lived Assets	$ 588,195	$ 597,511
UNITED STATES
Segment Reporting Information [Line Items]
Long-Lived Assets	255,791	253,115
Asia [Member]
Segment Reporting Information [Line Items]
Long-Lived Assets	275,260	283,549
Europe [Member]
Segment Reporting Information [Line Items]
Long-Lived Assets	$ 57,144	$ 60,847

CREDIT FACILITY (Details)

CREDIT FACILITY (Details) - USD ($) $ in Thousands	1 Months Ended	12 Months Ended
	Sep. 30, 2021	Dec. 31, 2021	Dec. 31, 2019	Dec. 31, 2020	Sep. 30, 2019
Line of Credit Facility [Line Items]
Additional borrowings	$ 85,000	$ 85,000	$ 347,486
Balance	400,000	395,000		$ 323,750
Fair value of long-term debt		$ 395,000
Average fixed rate		0.521%
Revolving Credit Facility [Member]
Line of Credit Facility [Line Items]
Line of credit facility, borrowing capacity					$ 500,000
Term Loan Facility [Member]
Line of Credit Facility [Line Items]
Line of credit facility, borrowing capacity					350,000
Unsecured Revolving Facility [Member]
Line of Credit Facility [Line Items]
Line of credit facility, borrowing capacity	200,000				$ 150,000
Increase in borrowing capacity	$ 50,000
Term Loan, Fixed Interest Rate [Member]
Line of Credit Facility [Line Items]
Balance		$ 255,719
Interest Rate		1.271%
Term Loan, Variable Interest Rate [Member]
Line of Credit Facility [Line Items]
Balance		$ 139,281
Interest Rate		0.89%
Revolving Facility, Variable Interest Rate [Member]
Line of Credit Facility [Line Items]
Interest Rate		0.89%
Unused Line Fee		0.10%
Credit availability under the Loan Agreement		$ 200,000		150,000
Foreign Exchange Forward [Member]
Line of Credit Facility [Line Items]
Derivative, notional amount		0		0
Interest Rate Swaps [Member]
Line of Credit Facility [Line Items]
Derivative, notional amount		$ 255,719		$ 273,219

CREDIT FACILITY - Debt obligati

CREDIT FACILITY - Debt obligation (Details) - USD ($) $ in Thousands	Dec. 31, 2021	Sep. 30, 2021	Dec. 31, 2020
Debt:
Term Loan Facility	$ 395,000	$ 400,000	$ 323,750
Less: debt issuance costs	(2,267)		(1,704)
Total debt	392,733		322,046
Less current portion of long-term debt	(20,000)		(17,500)
Total long-term debt	$ 372,733		$ 304,546

CREDIT FACILITY - Contractual m

CREDIT FACILITY - Contractual maturities (Details) - USD ($) $ in Thousands	Dec. 31, 2021	Sep. 30, 2021	Dec. 31, 2020
CREDIT FACILITY
2022	$ 20,000
2023	20,000
2024	20,000
2025	20,000
2026	315,000
Total	$ 395,000	$ 400,000	$ 323,750

CREDIT FACILITY - Interest expe

CREDIT FACILITY - Interest expense and unused line of credit fees (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
CREDIT FACILITY
Interest expense	$ 3,969	$ 5,080	$ 2,994
Amortization of debt issuance costs	822	519	186
Unused line of credit fees and other	168	153	236
Total interest expense	$ 4,959	$ 5,752	$ 3,416