Babcock & Wilcox Enterprises, I (BW) 10-Q 13 May 21 2021 Q1 Quarterly report Financial data

Cover

Cover - shares	3 Months Ended
	Mar. 31, 2021	May 06, 2021
Entity Information [Line Items]
Document Type	10-Q
Document Annual Report	true
Document Period End Date	Mar. 31, 2021
Document Transition Report	false
Entity File Number	001-36876
Entity Registrant Name	BABCOCK & WILCOX ENTERPRISES, INC
Entity Incorporation, State or Country Code	DE
Entity Tax Identification Number	47-2783641
Entity Address, Address Line One	1200 East Market Street
Entity Address, Address Line Two	Suite 650
Entity Address, City or Town	Akron
Entity Address, State or Province	OH
Entity Address, Postal Zip Code	44305
City Area Code	(330)
Local Phone Number	753-4511
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Non-accelerated Filer
Entity Small Business	true
Entity Emerging Growth Company	false
Entity Shell Company	false
Entity Common Stock, Shares Outstanding		85,727,419
Amendment Flag	false
Document Fiscal Year Focus	2021
Document Fiscal Period Focus	Q1
Entity Central Index Key	0001630805
Current Fiscal Year End Date	--12-31
Common Stock
Entity Information [Line Items]
Title of 12(b) Security	Common Stock, $0.01 par value
Trading Symbol	BW
Security Exchange Name	NYSE
8.125% Senior Notes Due 2026
Entity Information [Line Items]
Title of 12(b) Security	8.125% Senior Notes due 2026
Trading Symbol	BWSN
Security Exchange Name	NYSE
7.75% Series A Cumulative Perpetual Preferred Stock
Entity Information [Line Items]
Title of 12(b) Security	7.75% Series A Cumulative Perpetual Preferred Stock
Trading Symbol	BW PRA
Security Exchange Name	NYSE

CONDENSED CONSOLIDATED STATEMEN

CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS - USD ($) shares in Thousands, $ in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Income Statement [Abstract]
Revenues	$ 168,248	$ 148,554
Costs and expenses:
Cost of operations	131,385	114,628
Selling, general and administrative expenses	40,457	37,608
Advisory fees and settlement costs	3,291	4,239
Restructuring activities	993	1,951
Research and development costs	588	1,341
Gain on asset disposals, net	(2,004)	(915)
Total costs and expenses	174,710	158,852
Operating loss	(6,462)	(10,298)
Other (expense) income:
Interest expense	(14,223)	(22,091)
Interest income	109	40
Gain on sale of business	358	0
Benefit plans, net	9,098	7,536
Foreign exchange	(1,209)	(9,326)
Other – net	(278)	(206)
Total other expense	(6,145)	(24,047)
Loss before income tax (benefit) expense	(12,607)	(34,345)
Income tax expense (benefit)	2,836	(810)
Loss from continuing operations	(15,443)	(33,535)
Income from discontinued operations, net of tax	0	1,913
Net loss	(15,443)	(31,622)
Net (income) loss attributable to non-controlling interest	(21)	96
Net loss attributable to stockholders	$ (15,464)	$ (31,526)
Basic loss per share - continuing operations (in dollars per share)	$ (0.22)	$ (0.72)
Basic earnings per share - discontinued operations (in dollars per share)	0	0.04
Basic loss per share (in dollars per share)	(0.22)	(0.68)
Diluted loss per share - continuing operations (in dollars per share)	(0.22)	(0.72)
Diluted earnings per share - discontinued operations (in dollars per share)	0	0.04
Diluted loss per share (in dollars per share)	$ (0.22)	$ (0.68)
Shares used in the computation of earnings (loss) per share:
Basic (in shares)	71,396	46,403
Diluted (in shares)	71,396	46,403

CONDENSED CONSOLIDATED STATEM_2

CONDENSED CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (LOSS) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Statement of Comprehensive Income [Abstract]
Net loss	$ (15,443)	$ (31,622)
Other comprehensive income (loss):
Currency translation adjustments (CTA)	(70)	2,380
Reclassification of CTA to net loss	(4,512)	0
Benefit obligations:
Amortization of benefit plan benefits	198	(246)
Other comprehensive (loss) income	(4,384)	2,134
Total comprehensive loss	(19,827)	(29,488)
Comprehensive (loss) income attributable to non-controlling interest	3	154
Comprehensive loss attributable to stockholders	$ (19,824)	$ (29,334)

CONDENSED CONSOLIDATED BALANCE

CONDENSED CONSOLIDATED BALANCE SHEETS - USD ($) $ in Thousands	Mar. 31, 2021	Dec. 31, 2020
Statement of Financial Position [Abstract]
Cash and cash equivalents	$ 53,833	$ 57,338
Restricted cash and cash equivalents	4,613	10,085
Accounts receivable – trade, net	144,125	128,317
Accounts receivable – other	30,694	35,442
Contracts in progress	66,233	59,308
Inventories	67,864	67,161
Other current assets	24,014	26,421
Current assets held for sale	0	4,728
Total current assets	391,376	388,800
Net property, plant and equipment, and finance lease	85,848	85,078
Goodwill	47,354	47,363
Intangible assets	22,209	23,908
Right-of-use assets	9,513	10,814
Other assets	24,187	24,673
Non-current assets held for sale	1,870	11,156
Total assets	582,357	591,792
Accounts payable	78,503	73,481
Accrued employee benefits	13,740	13,906
Advance billings on contracts	81,753	64,002
Accrued warranty expense	19,537	25,399
Operating lease liabilities	3,578	3,995
Other accrued liabilities	70,572	81,744
Current liabilities held for sale	0	8,305
Total current liabilities	267,683	270,832
Revolving credit facilities	0	164,300
Last out term loans	73,330	183,330
Senior notes	155,509	0
Pension and other accumulated postretirement benefit liabilities	219,262	252,292
Non-current finance lease liabilities	33,155	29,690
Non-current operating lease liabilities	6,137	7,031
Other non-current liabilities	22,725	22,579
Total liabilities	777,801	930,054
Commitments and contingencies
Stockholders' deficit:
Common stock, par value $0.01 per share, authorized shares of 500,000; issued and outstanding shares of 85,664 and 54,452 at March 31, 2021 and December 31, 2020, respectively	5,101	4,784
Capital in excess of par value	1,330,134	1,164,436
Treasury stock at cost, 1,214 and 718 shares at March 31, 2021 and December 31, 2020, respectively	(109,298)	(105,990)
Accumulated deficit	(1,365,670)	(1,350,206)
Accumulated other comprehensive income (loss)	(56,774)	(52,390)
Stockholders' deficit attributable to shareholders	(196,507)	(339,366)
Non-controlling interest	1,063	1,104
Total stockholders' deficit	(195,444)	(338,262)
Total liabilities and stockholders' deficit	$ 582,357	$ 591,792

CONDENSED CONSOLIDATED BALANC_2

CONDENSED CONSOLIDATED BALANCE SHEETS (Parenthetical) - $ / shares	Mar. 31, 2021	Dec. 31, 2020
Statement of Financial Position [Abstract]
Common stock, par value (in dollars per share)	$ 0.01	$ 0.01
Common stock, authorized (in shares)	500,000,000	500,000,000
Common stock, issued (in shares)	85,664,000	54,452,000
Common stock, outstanding (in shares)	85,664,000	54,452,000
Treasury stock, at cost (in shares)	1,214,000	718,000

CONDENSED CONSOLIDATED STATEM_3

CONDENSED CONSOLIDATED STATEMENT OF STOCKHOLDERS' (DEFICIT) EQUITY - USD ($) shares in Thousands, $ in Thousands	Total	Common Stock	Capital In Excess of Par Value	Treasury Stock	Accumulated Deficit	Accumulated Other Comprehensive Loss	Non-controlling Interest
Beginning balance (in shares) at Dec. 31, 2019		46,374
Beginning balance at Dec. 31, 2019	$ (294,939)	$ 4,699	$ 1,142,614	$ (105,707)	$ (1,339,888)	$ 1,926	$ 1,417
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net (loss) income	(31,622)				(31,526)		(96)
Currency translation adjustments	2,322					2,380	(58)
Defined benefit obligations	(246)					(246)
Stock-based compensation charges (in shares)		33
Stock-based compensation charges	871	$ 4	876	(9)
Dividends to noncontrolling interest	(36)						(36)
Ending balance (in shares) at Mar. 31, 2020		46,407
Ending balance at Mar. 31, 2020	$ (323,650)	$ 4,703	1,143,490	(105,716)	(1,371,414)	4,060	1,227
Beginning balance (in shares) at Dec. 31, 2020	54,452	54,452
Beginning balance at Dec. 31, 2020	$ (338,262)	$ 4,784	1,164,436	(105,990)	(1,350,206)	(52,390)	1,104
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net (loss) income	(15,443)				(15,464)		21
Currency translation adjustments	(4,606)					(4,582)	(24)
Defined benefit obligations	198					198
Stock-based compensation charges (in shares)		1,725
Stock-based compensation charges	1,194	$ 22	4,480	(3,308)
Common stock offering (in shares)		29,487
Common stock offering	161,513	$ 295	161,218
Dividends to noncontrolling interest	$ (38)						(38)
Ending balance (in shares) at Mar. 31, 2021	85,664	85,664
Ending balance at Mar. 31, 2021	$ (195,444)	$ 5,101	$ 1,330,134	$ (109,298)	$ (1,365,670)	$ (56,774)	$ 1,063

CONDENSED CONSOLIDATED STATEM_4

CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Cash flows from operating activities:
Net loss	$ (15,443)	$ (31,622)
Adjustments to reconcile net loss to net cash used in operating activities:
Depreciation and amortization of long-lived assets	4,058	4,208
Amortization of deferred financing costs, debt discount and payment-in-kind interest	5,779	9,877
Amortization of guaranty fee	452	0
Non-cash operating lease expense	1,140	1,223
Gain on sale of business	(358)	0
Gains on asset disposals	(2,005)	(915)
Provision for (benefit from) deferred income taxes, including valuation allowances	1,557	(424)
Prior service cost amortization for pension and postretirement plans	198	(246)
Stock-based compensation, net of associated income taxes	4,502	880
Foreign exchange	1,209	9,326
Changes in assets and liabilities:
Accounts receivable	(11,629)	10,599
Contracts in progress	(6,911)	7,690
Advance billings on contracts	18,226	(7,321)
Inventories	(1,863)	1,286
Income taxes	(1,919)	(1,888)
Accounts payable	6,246	(26,451)
Accrued and other current liabilities	(17,127)	6,110
Accrued contract loss	(129)	(2,593)
Pension liabilities, accrued postretirement benefits and employee benefits	(33,640)	(10,258)
Other, net	(6,297)	(4,942)
Net cash used in operating activities	(53,954)	(35,461)
Cash flows from investing activities:
Purchase of property, plant and equipment	(1,410)	(2,394)
Proceeds from sale of business and assets, net	3,297	0
Purchases of available-for-sale securities	(3,394)	(6,352)
Sales and maturities of available-for-sale securities	5,495	3,420
Other, net	534	831
Net cash from (used in) investing activities	4,522	(4,495)
Cash flows from financing activities:
Issuance of senior notes	125,000	0
Shares of our common stock returned to treasury stock	(3,308)	(9)
Issuance of common stock, net	161,513	0
Debt issuance costs	(7,727)	(5,749)
Other, net	(241)	550
Net cash from financing activities	35,937	30,792
Effects of exchange rate changes on cash	4,518	(1,392)
Net decrease in cash, cash equivalents and restricted cash	(8,977)	(10,556)
Cash, cash equivalents and restricted cash, beginning of period	67,423	56,941
Cash, cash equivalents and restricted cash, end of period	58,446	46,385
U.S. Revolving Credit Facility
Cash flows from financing activities:
Borrowings under credit facilities	14,500	70,200
Repayments of lines of credit	(178,800)	(64,200)
Last Out Term Loans
Cash flows from financing activities:
Borrowings under credit facilities	0	30,000
Repayments of lines of credit	$ (75,000)	$ 0

BASIS OF PRESENTATION

BASIS OF PRESENTATION	3 Months Ended
	Mar. 31, 2021
Accounting Policies [Abstract]
BASIS OF PRESENTATION	BASIS OF PRESENTATION These interim Condensed Consolidated Financial Statements of Babcock & Wilcox Enterprises, Inc. (“B&W,” “management,” “we,” “us,” “our” or the “Company”) have been prepared in accordance with accounting principles generally accepted in the United States and Securities and Exchange Commission ("SEC") instructions for interim financial information, and should be read in conjunction with our Annual Report. We have included all adjustments, in the opinion of management, consisting only of normal, recurring adjustments, necessary for a fair presentation of the interim financial statements. We have eliminated all intercompany transactions and accounts. We present the notes to our Condensed Consolidated Financial Statements on the basis of continuing operations, unless otherwise stated. COVID-19 In December 2019, a novel strain of coronavirus, COVID-19, was identified in Wuhan, China and has subsequently spread globally. This global pandemic has disrupted business operations, trade, commerce, financial and credit markets, and daily life throughout the world. Our business has been, and continues to be, adversely impacted by the measures taken and restrictions imposed in the countries in which we operate and by local governments and others to control the spread of this virus. These measures and restrictions have varied widely and have been subject to significant changes from time to time depending on the changes in the severity of the virus in these countries and localities. These restrictions, including travel and curtailment of other activity, negatively impact our ability to conduct business. The volatility and variability of the virus has limited our ability to forecast the impact of the virus on our customers and our business. The continuing resurgence of COVID-19, including at least one new strain, has resulted in the reimposition of certain restrictions and may lead to other restrictions being implemented in response to efforts to reduce the spread of the virus. These varying and changing events have caused many of the projects we had anticipated would begin in 2020 to be delayed into 2021 and beyond. Many customers and projects require B&W's employees to travel to customer and project worksites. Certain customers and significant projects are located in areas where travel restrictions have been imposed, certain customers have closed or reduced on-site activities, and timelines for completion of certain projects have, as noted above, been extended into 2021 and beyond. Additionally, out of concern for our employees, even where restrictions permit employees to return to our offices and worksites, we have incurred additional costs to protect our employees as well as, advising those who are uncomfortable returning to worksites due to the pandemic that they are not required to do so for an indefinite period of time. The resulting uncertainty concerning, among other things, the spread and economic impact of the virus has also caused significant volatility and, at times, illiquidity in global equity and credit markets. The full extent of the COVID-19 impact on our operational and financial performance will depend on future developments, including the ultimate duration and spread of the pandemic and related actions taken by the U.S. government, state and local government officials, and international governments to prevent disease spread, as well as the availability and effectiveness of COVID-19 vaccinations in the U.S. and abroad, all of which are uncertain, out of our control, and cannot be predicted. Beginning in April 2020 and continuing as of May 13, 2021, as part of the Company’s response to the impact of the COVID-19 pandemic on its business, the Company continues to take a number of cash conservation and cost reduction measures which include: • suspension of our 401(k) company match for U.S. employees for 2021; • utilizing options for government loans and programs in the U.S. and abroad that are appropriate and available; and • deferring $20.9 million of the estimated Pension Plan contribution payments of $45.6 million that would have been due during 2021, in accordance with the American Rescue Plan Act of 2021 (the "ARPA relief plan") signed into law in March 2021. In January 2021, we made Pension Plan contributions of $23.1 million, excluding interest.

EARNINGS PER SHARE

EARNINGS PER SHARE	3 Months Ended
	Mar. 31, 2021
Earnings Per Share [Abstract]
EARNINGS PER SHARE	EARNINGS PER SHARE The following table sets forth the computation of basic and diluted earnings per share of our common stock, net of non-controlling interest: Three months ended March 31, (in thousands, except per share amounts) 2021 2020 Loss from continuing operations $ (15,464) $ (33,439) Income from discontinued operations, net of tax — 1,913 Net loss attributable to stockholders $ (15,464) $ (31,526) Weighted average shares used to calculate basic and diluted earnings (loss) per share 71,396 46,403 Basic and diluted (loss) earnings per share Continuing operations $ (0.22) $ (0.72) Discontinued operations — 0.04 Basic and diluted loss per share $ (0.22) $ (0.68) Because we incurred a net loss in the three months ended March 31, 2021 and 2020, basic and diluted shares are the same. If we had net income in the three months ended March 31, 2021, diluted shares would include an additional 1.6 million shares. If we had net income in the three months ended March 31, 2020, diluted shares would include an additional 0.5 million shares. We excluded 0.4 million and 0.5 million shares related to stock options from the diluted share calculation for the three months ended March 31, 2021 and 2020, respectively, because their effect would have been anti-dilutive.

SEGMENT REPORTING

SEGMENT REPORTING	3 Months Ended
	Mar. 31, 2021
Segment Reporting [Abstract]
SEGMENT REPORTING	SEGMENT REPORTING B&W’s innovative products and services are organized into three market-facing segments which changed in the third quarter of 2020 as part of the Company's strategic, market-focused organizational and re-branding initiative to accelerate growth and provide stakeholders improved visibility into our renewable and environmental growth platforms. Segment results for all periods have been restated for comparative purposes. Our reportable segments are as follows: • Babcock & Wilcox Renewable: Cost-effective technologies for efficient and environmentally sustainable power and heat generation, including waste-to-energy, biomass energy and black liquor systems for the pulp and paper industry. B&W’s leading technologies support a circular economy, diverting waste from landfills to use for power generation and replacing fossil fuels, while recovering metals and reducing emissions. • Babcock & Wilcox Environmental: A full suite of best-in-class emissions control and environmental technology solutions for utility, waste to energy, biomass, carbon black, and industrial steam generation applications around the world. B&W’s broad experience includes systems for cooling, ash handling, particulate control, nitrogen oxides and sulfur dioxides removal, chemical looping for carbon control, and mercury control. • Babcock & Wilcox Thermal: Steam generation equipment, aftermarket parts, construction, maintenance and field services for plants in the power generation, oil and gas, and industrial sectors. B&W has an extensive global base of installed equipment for utilities and general industrial applications including refining, petrochemical, food processing, metals and others. Revenues exclude eliminations of revenues generated from sales to other segments or to other product lines within the segment. An analysis of our operations by segment is as follows: Three months ended March 31, (in thousands) 2021 2020 Revenues: B&W Renewable segment B&W Renewable $ 17,997 $ 22,338 Vølund 10,814 13,661 28,811 35,999 B&W Environmental segment B&W Environmental 17,433 12,935 SPIG 11,184 11,337 GMAB 2,543 1,648 31,160 25,920 B&W Thermal segment B&W Thermal 108,281 86,683 108,281 86,683 Other (4) (48) $ 168,248 $ 148,554 The presentation of the components of our adjusted EBITDA in the table below is consistent with the way our chief operating decision maker reviews the results of our operations and makes strategic decisions about our business. Items such as gains or losses on asset sales, MTM pension adjustments, restructuring costs, impairments, losses on debt extinguishment, costs related to financial consulting required under our U.S. Revolving Credit Facility, research and development costs and other costs that may not be directly controllable by segment management are not allocated to the segments. Adjusted EBITDA for each segment is presented below with a reconciliation to net income (loss) attributable to stockholders. Three months ended March 31, (in thousands) 2021 2020 Adjusted EBITDA (1) B&W Renewable segment $ 204 $ (1,434) B&W Environmental segment 1,101 270 B&W Thermal segment 10,430 7,606 Corporate (2,685) (4,143) Research and development costs (588) (1,341) 8,462 958 Restructuring activities (993) (1,951) Financial advisory services (933) (929) Advisory fees for settlement costs and liquidity planning (1,978) (2,614) Litigation legal costs (380) (696) Stock compensation (7,829) (712) Interest on letters of credit included in cost of operations (286) (152) Loss from business held for sale (483) (788) Depreciation & amortization (4,058) (4,208) Gain (loss) from a non-strategic business 12 (121) Gain on asset disposals, net 2,004 915 Operating loss (6,462) (10,298) Interest expense, net (14,114) (22,051) Gain on sale of business 358 — Net pension benefit 9,098 7,536 Foreign exchange (1,209) (9,326) Other – net (278) (206) Total other income (expense) (6,145) (24,047) Loss before income tax (benefit) expense (12,607) (34,345) Income tax (benefit) expense 2,836 (810) Loss from continuing operations (15,443) (33,535) Income from discontinued operations, net of tax — 1,913 Net loss (15,443) (31,622) Net (income) loss attributable to non-controlling interest (21) 96 Net loss attributable to stockholders $ (15,464) $ (31,526) (1) Adjusted EBITDA for the three months ended March 31, 2020, excludes losses related to a non-strategic business and interest on letters of credit included in cost of operations that were previously included in Adjusted EBITDA and total $(0.1) million and $(0.2) million, respectively. We do not separately identify or report our assets by segment as our chief operating decision maker does not consider assets by segment to be a critical measure by which performance is measured.

REVENUE RECOGNITION AND CONTRAC

REVENUE RECOGNITION AND CONTRACTS	3 Months Ended
	Mar. 31, 2021
Revenue from Contract with Customer [Abstract]
REVENUE RECOGNITION AND CONTRACTS	REVENUE RECOGNITION AND CONTRACTS Revenue Recognition A performance obligation is a contractual promise to transfer a distinct good or service to the customer. A contract's transaction price is allocated to each distinct performance obligation and is recognized as revenue when (point in time) or as (over time) the performance obligation is satisfied. Revenue from goods and services transferred to customers at a point in time, which includes certain aftermarket parts and services, accounted for 27% and 31% of our revenue for the three months ended March 31, 2021 and 2020, respectively. Revenue from products and services transferred to customers over time, which primarily relates to customized, engineered solutions and construction services, accounted for 73% and 69% of our revenue for the three months ended March 31, 2021 and 2020, respectively. Refer to Note 3 for our disaggregation of revenue by product line. Contract Balances The following represents the components of our contracts in progress and advance billings on contracts included in our Condensed Consolidated Balance Sheets: (in thousands) March 31, 2021 December 31, 2020 $ Change % Change Contract assets - included in contracts in progress: Costs incurred less costs of revenue recognized $ 27,096 $ 25,888 $ 1,208 5 % Revenues recognized less billings to customers 39,137 33,420 5,717 17 % Contracts in progress $ 66,233 $ 59,308 $ 6,925 12 % Contract liabilities - included in advance billings on contracts: Billings to customers less revenues recognized $ 80,328 $ 61,884 $ 18,444 30 % Costs of revenue recognized less cost incurred 1,425 2,118 (693) (33) % Advance billings on contracts $ 81,753 $ 64,002 $ 17,751 28 % Net contract balance $ (15,520) $ (4,694) $ (10,826) 231 % Accrued contract losses $ 453 $ 582 $ (129) (22) % Backlog On March 31, 2021 we had $535.0 million of remaining performance obligations, which we also refer to as total backlog. We expect to recognize approximately 51.0%, 18.7% and 30.3% of our remaining performance obligations as revenue in the remainder of 2021, 2022 and thereafter, respectively. Changes in Contract Estimates In the three months ended March 31, 2021 and 2020, we recognized changes in estimated gross profit related to long-term contracts accounted for on the over time basis, which are summarized as follows: Three months ended March 31, (in thousands) 2021 2020 Increases in gross profit for changes in estimates for over time contracts $ 3,025 $ 8,182 Decreases in gross profit for changes in estimates for over time contracts (1,358) (4,845) Net changes in gross profit for changes in estimates for over time contracts $ 1,667 $ 3,337 B&W Renewable EPC Loss Contracts We had six B&W Renewable EPC contracts for renewable energy facilities in Europe that were loss contracts at December 31, 2017. The scope of these EPC (Engineer, Procure and Construct) contracts extended beyond our core technology, products and services. In addition to these loss contracts, we have one remaining extended scope contract in our Babcock & Wilcox Renewable segment which turned into a loss contract in the fourth quarter of 2019. In the three months ended March 31, 2021 and March 31, 2020, we recorded $0.1 million and $0.1 million in net gains, respectively, inclusive of warranty expense as described in Note 10, resulting from changes in the estimated revenues and costs to complete the six European B&W Renewable EPC loss contracts. All six contracts were approximately 100% complete at March 31, 2021; total liquidated damages associated with these six contracts were $92.5 million and $86.5 million at March 31, 2021 and March 31, 2020, respectively. The change in liquidated damages was due to foreign exchange impact. In 2019, one of our other B&W Renewable energy contracts turned into a loss contract due to delays and other start-up costs prior to turnover to the client in October 2019. In the three months ended March 31, 2021 and March 31, 2020, we did not recognize additional charges on this contract. As of March 31, 2021, this contract was approximately 99% complete. In September 2017, we identified the failure of a structural steel beam on a contact for a biomass plant in the United Kingdom, The engineering, design and manufacturing of the steel structure were the responsibility of our subcontractors. A similar design was also used on two other contracts, and although no structural failure occurred on these two other contracts, work was also stopped in certain restricted areas while we added reinforcement to the structures, which also resulted in delays. The total costs related to the structural steel issues on these three contracts were estimated to be approximately $36 million, which is included in the March 31, 2021 estimated losses at completion for these three contracts. We are continuing to aggressively pursue recovery of this cost from responsible subcontractors. In October 2020, we entered into a settlement agreement with an insurer under which we received a settlement of $26.0 million to settle claims in connection with five of six European B&W Renewable EPC loss contracts disclosed above. The Company is continuing to pursue other additional potential claims where appropriate and available. B&W Environmental Loss Contracts At March 31, 2021, the B&W Environmental segment had two significant loss contracts, each of which are contracts for a dry cooling system for a gas-fired power plant in the United States. In the three months ended March 31, 2021 and March 31, 2020, we did not recognize additional charges on these contracts. As of March 31, 2021, the first contract was approximately 100% complete and the second contract was approximately 99% complete.

INVENTORIES

INVENTORIES	3 Months Ended
	Mar. 31, 2021
Inventory Disclosure [Abstract]
INVENTORIES	INVENTORIES The components of inventories are as follows: (in thousands) March 31, 2021 December 31, 2020 Raw materials and supplies $ 46,851 $ 46,659 Work in progress 8,460 8,195 Finished goods 12,553 12,307 Total inventories $ 67,864 $ 67,161

PROPERTY, PLANT & EQUIPMENT, &

PROPERTY, PLANT & EQUIPMENT, & FINANCE LEASE	3 Months Ended
	Mar. 31, 2021
Property, Plant and Equipment [Abstract]
PROPERTY, PLANT & EQUIPMENT, & FINANCE LEASE	PROPERTY, PLANT & EQUIPMENT, & FINANCE LEASE Property, plant and equipment less accumulated depreciation is as follows: (in thousands) March 31, 2021 December 31, 2020 Land $ 1,533 $ 1,584 Buildings 33,902 34,207 Machinery and equipment 150,605 151,399 Property under construction 5,182 5,336 191,222 192,526 Less accumulated depreciation 137,025 135,925 Net property, plant and equipment 54,197 56,601 Finance lease 34,254 30,551 Less finance lease accumulated amortization 2,603 2,074 Net property, plant and equipment, and finance lease $ 85,848 $ 85,078

GOODWILL

GOODWILL	3 Months Ended
	Mar. 31, 2021
Goodwill and Intangible Assets Disclosure [Abstract]
GOODWILL	GOODWILL The following summarizes the changes in the net carrying amount of goodwill as of March 31, 2021: (in thousands) B&W Renewable B&W Environmental B&W Thermal Total Balance at December 31, 2020 $ 10,211 $ 5,673 $ 31,479 $ 47,363 Currency translation adjustments (1) (1) (7) (9) Balance at March 31, 2021 $ 10,210 $ 5,672 $ 31,472 $ 47,354 Goodwill is tested for impairment annually and when impairment indicators exist. No impairment indicators were identified during the three months ended March 31, 2021. Because the B&W Thermal, B&W Construction Co., LLC, B&W Renewable and B&W Environmental reporting units each had negative carrying values, reasonable changes in assumptions would not indicate impairment.

INTANGIBLE ASSETS

INTANGIBLE ASSETS	3 Months Ended
	Mar. 31, 2021
Goodwill and Intangible Assets Disclosure [Abstract]
INTANGIBLE ASSETS	INTANGIBLE ASSETS Our intangible assets are as follows: (in thousands) March 31, 2021 December 31, 2020 Definite-lived intangible assets Customer relationships $ 24,102 $ 24,862 Unpatented technology 15,321 15,713 Patented technology 3,114 2,642 Tradename 12,769 13,088 All other 9,418 9,262 Gross value of definite-lived intangible assets 64,724 65,567 Customer relationships amortization (19,762) (19,537) Unpatented technology amortization (7,149) (6,751) Patented technology amortization (2,616) (2,593) Tradename amortization (4,978) (4,831) All other amortization (9,315) (9,252) Accumulated amortization (43,820) (42,964) Net definite-lived intangible assets $ 20,904 $ 22,603 Indefinite-lived intangible assets Trademarks and trade names $ 1,305 $ 1,305 Total intangible assets, net $ 22,209 $ 23,908 The following summarizes the changes in the carrying amount of intangible assets: Three months ended March 31, (in thousands) 2021 2020 Balance at beginning of period $ 23,908 $ 25,300 Amortization expense (856) (895) Currency translation adjustments (843) (73) Balance at end of the period $ 22,209 $ 24,332 Amortization of intangible assets is included in cost of operations and SG&A in our Condensed Consolidated Statement of Operations but is not allocated to segment results. Estimated future intangible asset amortization expense is as follows (in thousands): Amortization Expense Year ending December 31, 2021 $ 2,470 Year ending December 31, 2022 3,321 Year ending December 31, 2023 3,319 Year ending December 31, 2024 3,247 Year ending December 31, 2025 2,549 Year ending December 31, 2026 1,292 Thereafter 4,706

LEASES

LEASES	3 Months Ended
	Mar. 31, 2021
Leases [Abstract]
LEASES	LEASES Certain fixed assets for our Copley, Ohio location were sold on March 15, 2021, as described in Note 23. In conjunction with the sale, we executed a leaseback agreement also commencing March 16, 2021 and expiring on March 31, 2033. The lease is classified as a finance lease with total future minimum payments during the initial term of the lease of approximately $5.7 million as of March 31, 2021. An incremental borrowing rate of 7% was used to determine the ROU asset. We recorded a $3.7 million ROU asset in net property, plant and equipment, and finance lease and corresponding liabilities in other accrued liabilities and other non-current finance liabilities in the Condensed Consolidated Balance Sheets as of March 31, 2021 . The components of lease expense included on our Condensed Consolidated Statements of Operations were as follows: Three months ended March 31, (in thousands) Classification 2021 2020 Operating lease expense: Operating lease expense Selling, general and administrative expenses $ 1,339 $ 1,507 Short-term lease expense Selling, general and administrative expenses 1,155 188 Variable lease expense (1) Selling, general and administrative expenses 208 776 Total operating lease expense $ 2,702 $ 2,471 Finance lease expense: Amortization of right-of-use assets Selling, general and administrative expenses $ 529 $ 515 Interest on lease liabilities Interest expense 616 615 Total finance lease expense $ 1,145 $ 1,130 Sublease income (2) Other – net $ (22) $ (22) Net lease cost $ 3,825 $ 3,579 (1) Variable lease expense primarily consists of common area maintenance expenses paid directly to lessors of real estate leases. (2) Sublease income excludes rental income from owned properties, which is not material. Other information related to leases is as follows: Three months ended March 31, (in thousands) 2021 2020 Cash paid for amounts included in the measurement of lease liabilities: Operating cash flows from operating leases $ 1,355 $ 1,400 Operating cash flows from finance leases 616 615 Financing cash flows from finance leases 203 (586) March 31, 2021 December 31, 2020 Right-of-use assets obtained in exchange for lease liabilities: Operating leases $ 491 $ 2,629 Finance leases $ 3,702 $ 146 Weighted-average remaining lease term: Operating leases (in years) 3.0 3.1 Finance leases (in years) 13.5 13.9 Weighted-average discount rate: Operating leases 9.28 % 9.26 % Finance leases 7.92 % 8.00 % Amounts relating to leases were presented on our Condensed Consolidated Balance Sheets in the following line items: (in thousands) Assets: Classification March 31, 2021 December 31, 2020 Operating lease assets Right-of-use assets $ 9,513 $ 10,814 Finance lease assets Net property, plant and equipment, and finance lease 31,651 28,477 Total non-current lease assets $ 41,164 $ 39,291 Liabilities: Current Operating lease liabilities Operating lease liabilities $ 3,578 $ 3,995 Finance lease liabilities Other accrued liabilities 920 886 Non-current Operating lease liabilities Non-current operating lease liabilities 6,137 7,031 Finance lease liabilities Non-current finance lease liabilities 33,155 29,690 Total lease liabilities $ 43,790 $ 41,602 Future minimum lease payments required under non-cancellable leases as of March 31, 2021 were as follows: (in thousands) Operating Leases Finance Leases Total 2021 (excluding the three months ended March 31, 2021) $ 3,467 $ 2,629 $ 6,096 2022 3,439 3,793 7,232 2023 2,407 3,879 6,286 2024 1,326 3,944 5,270 2025 313 3,969 4,282 Thereafter 19 38,412 38,431 Total $ 10,971 $ 56,626 $ 67,597 Less imputed interest (1,256) (22,551) (23,807) Lease liability $ 9,715 $ 34,075 $ 43,790
LEASES	LEASES Certain fixed assets for our Copley, Ohio location were sold on March 15, 2021, as described in Note 23. In conjunction with the sale, we executed a leaseback agreement also commencing March 16, 2021 and expiring on March 31, 2033. The lease is classified as a finance lease with total future minimum payments during the initial term of the lease of approximately $5.7 million as of March 31, 2021. An incremental borrowing rate of 7% was used to determine the ROU asset. We recorded a $3.7 million ROU asset in net property, plant and equipment, and finance lease and corresponding liabilities in other accrued liabilities and other non-current finance liabilities in the Condensed Consolidated Balance Sheets as of March 31, 2021 . The components of lease expense included on our Condensed Consolidated Statements of Operations were as follows: Three months ended March 31, (in thousands) Classification 2021 2020 Operating lease expense: Operating lease expense Selling, general and administrative expenses $ 1,339 $ 1,507 Short-term lease expense Selling, general and administrative expenses 1,155 188 Variable lease expense (1) Selling, general and administrative expenses 208 776 Total operating lease expense $ 2,702 $ 2,471 Finance lease expense: Amortization of right-of-use assets Selling, general and administrative expenses $ 529 $ 515 Interest on lease liabilities Interest expense 616 615 Total finance lease expense $ 1,145 $ 1,130 Sublease income (2) Other – net $ (22) $ (22) Net lease cost $ 3,825 $ 3,579 (1) Variable lease expense primarily consists of common area maintenance expenses paid directly to lessors of real estate leases. (2) Sublease income excludes rental income from owned properties, which is not material. Other information related to leases is as follows: Three months ended March 31, (in thousands) 2021 2020 Cash paid for amounts included in the measurement of lease liabilities: Operating cash flows from operating leases $ 1,355 $ 1,400 Operating cash flows from finance leases 616 615 Financing cash flows from finance leases 203 (586) March 31, 2021 December 31, 2020 Right-of-use assets obtained in exchange for lease liabilities: Operating leases $ 491 $ 2,629 Finance leases $ 3,702 $ 146 Weighted-average remaining lease term: Operating leases (in years) 3.0 3.1 Finance leases (in years) 13.5 13.9 Weighted-average discount rate: Operating leases 9.28 % 9.26 % Finance leases 7.92 % 8.00 % Amounts relating to leases were presented on our Condensed Consolidated Balance Sheets in the following line items: (in thousands) Assets: Classification March 31, 2021 December 31, 2020 Operating lease assets Right-of-use assets $ 9,513 $ 10,814 Finance lease assets Net property, plant and equipment, and finance lease 31,651 28,477 Total non-current lease assets $ 41,164 $ 39,291 Liabilities: Current Operating lease liabilities Operating lease liabilities $ 3,578 $ 3,995 Finance lease liabilities Other accrued liabilities 920 886 Non-current Operating lease liabilities Non-current operating lease liabilities 6,137 7,031 Finance lease liabilities Non-current finance lease liabilities 33,155 29,690 Total lease liabilities $ 43,790 $ 41,602 Future minimum lease payments required under non-cancellable leases as of March 31, 2021 were as follows: (in thousands) Operating Leases Finance Leases Total 2021 (excluding the three months ended March 31, 2021) $ 3,467 $ 2,629 $ 6,096 2022 3,439 3,793 7,232 2023 2,407 3,879 6,286 2024 1,326 3,944 5,270 2025 313 3,969 4,282 Thereafter 19 38,412 38,431 Total $ 10,971 $ 56,626 $ 67,597 Less imputed interest (1,256) (22,551) (23,807) Lease liability $ 9,715 $ 34,075 $ 43,790
LEASES	LEASES Certain fixed assets for our Copley, Ohio location were sold on March 15, 2021, as described in Note 23. In conjunction with the sale, we executed a leaseback agreement also commencing March 16, 2021 and expiring on March 31, 2033. The lease is classified as a finance lease with total future minimum payments during the initial term of the lease of approximately $5.7 million as of March 31, 2021. An incremental borrowing rate of 7% was used to determine the ROU asset. We recorded a $3.7 million ROU asset in net property, plant and equipment, and finance lease and corresponding liabilities in other accrued liabilities and other non-current finance liabilities in the Condensed Consolidated Balance Sheets as of March 31, 2021 . The components of lease expense included on our Condensed Consolidated Statements of Operations were as follows: Three months ended March 31, (in thousands) Classification 2021 2020 Operating lease expense: Operating lease expense Selling, general and administrative expenses $ 1,339 $ 1,507 Short-term lease expense Selling, general and administrative expenses 1,155 188 Variable lease expense (1) Selling, general and administrative expenses 208 776 Total operating lease expense $ 2,702 $ 2,471 Finance lease expense: Amortization of right-of-use assets Selling, general and administrative expenses $ 529 $ 515 Interest on lease liabilities Interest expense 616 615 Total finance lease expense $ 1,145 $ 1,130 Sublease income (2) Other – net $ (22) $ (22) Net lease cost $ 3,825 $ 3,579 (1) Variable lease expense primarily consists of common area maintenance expenses paid directly to lessors of real estate leases. (2) Sublease income excludes rental income from owned properties, which is not material. Other information related to leases is as follows: Three months ended March 31, (in thousands) 2021 2020 Cash paid for amounts included in the measurement of lease liabilities: Operating cash flows from operating leases $ 1,355 $ 1,400 Operating cash flows from finance leases 616 615 Financing cash flows from finance leases 203 (586) March 31, 2021 December 31, 2020 Right-of-use assets obtained in exchange for lease liabilities: Operating leases $ 491 $ 2,629 Finance leases $ 3,702 $ 146 Weighted-average remaining lease term: Operating leases (in years) 3.0 3.1 Finance leases (in years) 13.5 13.9 Weighted-average discount rate: Operating leases 9.28 % 9.26 % Finance leases 7.92 % 8.00 % Amounts relating to leases were presented on our Condensed Consolidated Balance Sheets in the following line items: (in thousands) Assets: Classification March 31, 2021 December 31, 2020 Operating lease assets Right-of-use assets $ 9,513 $ 10,814 Finance lease assets Net property, plant and equipment, and finance lease 31,651 28,477 Total non-current lease assets $ 41,164 $ 39,291 Liabilities: Current Operating lease liabilities Operating lease liabilities $ 3,578 $ 3,995 Finance lease liabilities Other accrued liabilities 920 886 Non-current Operating lease liabilities Non-current operating lease liabilities 6,137 7,031 Finance lease liabilities Non-current finance lease liabilities 33,155 29,690 Total lease liabilities $ 43,790 $ 41,602 Future minimum lease payments required under non-cancellable leases as of March 31, 2021 were as follows: (in thousands) Operating Leases Finance Leases Total 2021 (excluding the three months ended March 31, 2021) $ 3,467 $ 2,629 $ 6,096 2022 3,439 3,793 7,232 2023 2,407 3,879 6,286 2024 1,326 3,944 5,270 2025 313 3,969 4,282 Thereafter 19 38,412 38,431 Total $ 10,971 $ 56,626 $ 67,597 Less imputed interest (1,256) (22,551) (23,807) Lease liability $ 9,715 $ 34,075 $ 43,790

ACCRUED WARRANTY EXPENSE

ACCRUED WARRANTY EXPENSE	3 Months Ended
	Mar. 31, 2021
Product Warranties Disclosures [Abstract]
ACCRUED WARRANTY EXPENSE	ACCRUED WARRANTY EXPENSE We may offer assurance type warranties on products and services we sell. Changes in the carrying amount of our accrued warranty expense are as follows: Three months ended March 31, (in thousands) 2021 2020 Balance at beginning of period $ 25,399 $ 33,376 Additions 1,475 1,350 Expirations and other changes (1,318) (517) Payments (5,943) (3,119) Translation and other (76) (137) Balance at end of period $ 19,537 $ 30,953 We accrue estimated expense included in cost of operations on our Condensed Consolidated Statements of Operations to satisfy contractual warranty requirements when we recognize the associated revenues on the related contracts, or in the case of a loss contract, the full amount of the estimated warranty costs is accrued when the contract becomes a loss contract. In addition, we record specific provisions or reductions where we expect the actual warranty costs to significantly differ from the accrued estimates. Such changes could have a material effect on our consolidated financial condition, results of operations and cash flows.

RESTRUCTURING ACTIVITIES

RESTRUCTURING ACTIVITIES	3 Months Ended
	Mar. 31, 2021
Restructuring and Related Activities [Abstract]
RESTRUCTURING ACTIVITIES	RESTRUCTURING ACTIVITIES The Company incurred restructuring charges in the three months ended March 31, 2021 and 2020. The charges primarily consist of severance costs related to actions taken, including as part of the Company’s strategic, market-focused organizational and re-branding initiative. During 2021, these charges also include actions taken to address the impact of COVID-19 on our business. The following table summarizes the restructuring activity incurred by segment: Three months ended March 31, Three months ended March 31, 2021 2020 (in thousands) Total Severance and related costs Other (1) Total Severance and related costs Other (1) B&W Renewable segment $ 509 $ 453 $ 56 $ 801 $ 658 $ 143 B&W Environmental segment 89 35 54 140 57 83 B&W Thermal segment 348 12 336 941 386 555 Corporate 47 — 47 69 — 69 $ 993 $ 500 $ 493 $ 1,951 $ 1,101 $ 850 Total Severance and related costs Other (1) Cumulative costs to date $ 41,307 33,713 7,594 (1) Other amounts consist primarily of exit, relocation, COVID-19 related and other costs. Restructuring liabilities are included in other accrued liabilities on our Condensed Consolidated Balance Sheets. Activity related to the restructuring liabilities is as follows: Three months ended March 31, (in thousands) 2021 2020 Balance at beginning of period $ 8,146 $ 5,358 Restructuring expense 993 1,951 Payments (1,117) (1,968) Balance at end of period $ 8,022 $ 5,341 The payments shown above for the three months ended March 31, 2021 and 2020 relate primarily to severance. Accrued restructuring liabilities at March 31, 2021 and 2020 relate primarily to employee termination benefits.

PENSION PLANS AND OTHER POSTRET

PENSION PLANS AND OTHER POSTRETIREMENT BENEFITS	3 Months Ended
	Mar. 31, 2021
Retirement Benefits [Abstract]
PENSION PLANS AND OTHER POSTRETIREMENT BENEFITS	PENSION PLANS AND OTHER POSTRETIREMENT BENEFITS Components of net periodic benefit cost (benefit) included in net income (loss) are as follows: Pension Benefits Other Benefits Three months ended March 31, Three months ended March 31, (in thousands) 2021 2020 2021 2020 Interest cost $ 5,671 $ 8,261 $ 39 $ 72 Expected return on plan assets (15,009) (15,641) — — Amortization of prior service cost (credit) 28 43 173 (271) Benefit plans, net (1) (9,310) (7,337) 212 (199) Service cost included in COS (2) 217 211 6 5 Net periodic benefit cost (benefit) $ (9,093) $ (7,126) $ 218 $ (194) (1) Benefit plans, net , which is presented separately in the Condensed Consolidated Statements of Operations, is not allocated to the segments. (2) Service cost related to a small group of active participants is presented within cost of operations in the Condensed Consolidated Statement of Operations and is allocated to the B&W Thermal segment. There were no MTM adjustments for our pension and other postretirement benefit plans during the three months ended March 31, 2021 and 2020. We made contributions to our pension and other postretirement benefit plans totaling $24.0 million and $0.4 million during the three months ended March 31, 2021 and 2020 , respectively. Contributions made during the three months ended March 31, 2021 include $0.4 million of interest as required per the CARES Act that was signed into law on March 27, 2020.

2021 SENIOR NOTES OFFERING

2021 SENIOR NOTES OFFERING	3 Months Ended
	Mar. 31, 2021
Debt Disclosure [Abstract]
2021 SENIOR NOTES OFFERING	2021 SENIOR NOTES OFFERING On February 12, 2021, we completed a public offering of $125.0 million aggregate principal amount of our 8.125% senior notes due 2026. The offering was conducted pursuant to an underwriting agreement (the “Notes Underwriting Agreement”) dated February 10, 2021, between us and B. Riley Securities, Inc., as representative of the several underwriters (the “Underwriters”). At the completion, we received gross proceeds of approximately $125.0 million. Net proceeds received were approximately $120.0 million after deducting underwriting discounts and commissions, but before expenses. The Senior Notes were issued in denominations of $25.00 per Senior Note and in integral multiples thereof. In addition to the public offering, we issued $35.0 million of Senior Notes to B. Riley Financial, Inc. in exchange for a deemed prepayment of our existing Last Out Term Loan Tranche A-3 in a concurrent private offering. The components of the Senior Notes are as follows: (in thousands) March 31, 2021 8.125% Senior Notes due 2026 $ 160,000 Unamortized deferred financing costs 4,491 Net debt balance $ 155,509 The Senior Notes are senior unsecured obligations of the Company and rank equally in right of payment with all of the Company’s other existing and future senior unsecured and unsubordinated indebtedness. The Senior Notes bear interest at the rate of 8.125% per annum. Interest on the Senior Notes is payable quarterly in arrears on January 31, April 30, July 31 and October 31 of each year, commencing on April 30, 2021. The Senior Notes will mature on February 28, 2026. We may, at our option, at any time and from time to time, redeem the Senior Notes for cash in whole or in part (i) on or after February 28, 2022 and prior to February 28, 2023, at a price equal to $25.75 per Senior Note, plus accrued and unpaid interest to, but excluding, the date of redemption, (ii) on or after February 28, 2023 and prior to February 29, 2024, at a price equal to $25.50 per Senior Note, plus accrued and unpaid interest to, but excluding, the date of redemption, (iii) on or after February 29, 2024 and prior to February 28, 2025, at a price equal to $25.25 per Senior Note, plus accrued and unpaid interest to, but excluding, the date of redemption and (iv) on or after February 28, 2025 and prior to maturity, at a price equal to 100% of their principal amount, plus accrued and unpaid interest to, but excluding, the date of redemption. On and after any redemption date, interest will cease to accrue on the redeemed Senior Notes. The Indenture governing the Senior Notes contains customary events of default and cure provisions. On March 31, 2021, we entered into a sales agreement with B. Riley Securities, Inc., a related party, in which we may sell to or through B. Riley Securities, Inc., from time to time, additional Senior Notes up to an aggregated principal amount of $150.0 million of Senior Notes. The Senior Notes will have the same terms as (other than date of issuance), form a single series of debt securities with and have the same CUSIP number and be fungible with, the Senior Notes issued February 12, 2021, as described above. Senior Notes - Subsequent Event As of May 10, 2021, the Company has sold $10.6 million aggregate principal amount of Senior Notes for $11.0 million gross proceeds related to the March 31, 2021 sales agreement disclosed above. The Company received $10.7 million of net cash proceeds after commission and fees. Exchange Agreement On February 12, 2021, the Company and B. Riley entered into the Exchange Agreement pursuant to which we issued to B. Riley, a related party, $35.0 million aggregate principal amount of Senior Notes in exchange for a deemed prepayment of $35.0 million of our existing Tranche A term loan with B. Riley Financial (the “Exchange”). The components of the Last Out Term Loans by Tranche are as follows: March 31, 2021 (in thousands) A-3 Proceeds (1) $ 61,660 Discount and fees 8,650 Paid-in-kind interest 3,020 Net debt balance $ 73,330 (1) Tranche A-3 proceeds represent the net proceeds after the $39.7 million principal prepayment from the July 2019 Equitization Transactions and a $40.0 million principal repayment in March 2021 December 31, 2020 (in thousands) A-3 A-4 A-6 Total Proceeds (1) $ 101,660 $ 30,000 $ 40,000 $ 171,660 Discount and fees 8,650 — — 8,650 Paid-in-kind interest 3,020 — — 3,020 Net debt balance $ 113,330 $ 30,000 $ 40,000 $ 183,330 (1) Tranche A-3 proceeds represent the net proceeds after the $39.7 million principal prepayment from the July 2019 Equitization Transactions. Last Out Term Loans are incurred under our A&R Credit Agreement and are pari passu with the U.S. Revolving Credit Facility except for certain payment subordination provisions. The Last Out Term Loans are subject to the same representations and warranties, covenants and events of default as the U.S. Revolving Credit Facility. In connection with the effectiveness of the A&R Credit Agreement, the maturity date for the Last Out Term Loans was extended to December 30, 2022. On February 12, 2021, in connection with the Exchange described in Note 13, the interest rate on the remaining Last Out Term Loan Tranche A balances was reduced to 6.625% from 12.0%. Interest expense associated with the Last Out Term Loans is detailed in Note 17. Tranche A-3 Effective with Amendment No. 16 to our previous Amended Credit Agreement, we borrowed $150.0 million face value from B. Riley, a related party, under Tranche A-3. The $141.4 million net proceeds from Tranche A-3 were primarily used to pay the amounts due under the settlement agreements covering certain European B&W Renewable loss projects as described in Note 4, with the remainder used for working capital and general corporate purposes. As part of the Equitization Transactions of July 23, 2019, we prepaid $39.7 million principal of Tranche A-3. Also, on March 4, 2021, effective with A&R Amendment No. 3, we paid down an additional $40.0 million on our existing Tranche A-3. Tranche A-4 On January 31, 2020, effective with Amendment No. 20 to the Amended Credit Agreement, we borrowed $30.0 million face value of the Tranche A-4 from B. Riley, a related party and received net proceeds of $26.3 million after incurring total fees of $3.7 million. On March 4, 2021, effective with A&R Amendment No. 3, we paid down the $30.0 million outstanding on our existing Tranche A-4. Tranche A-5 On January 31, 2020, we entered into Amendment No. 20 to the Amended Credit Agreement. Amendment No. 20 provides an incremental Tranche A-5 to be extended prior to maturity of the Last Out Term Loans under the Amended Credit Agreement in the event certain customer letters of credit are drawn. The terms of Tranche A-5 are the same as the terms for the Tranche A-3 under the Amended Credit Agreement. As of May 13, 2021, no borrowings occurred under Tranche A-5. Tranche A-6 On May 14, 2020, effective with the A&R Credit Agreement, we borrowed $30.0 million face value of the Tranche A-6 from B. Riley, a related party, as described in Note 16. On November 30, 2020, we borrowed an additional $10.0 million face value of the Tranche A-6 pursuant to the terms of the A&R Credit Agreement which required the proceeds to be applied as a permanent reduction of the U.S. Revolving Credit Facility. As described in Note 13, on February 12, 2021, we issued $35.0 million of Senior Notes to B. Riley Financial, Inc. in exchange for a deemed prepayment of our existing Tranche A-6 as part of the Exchange. Also, on March 4, 2021, effective with A&R Amendment No. 3, we paid down the remaining $5.0 million outstanding on our existing Tranche A-6. Tranche A-7

2021 COMMON STOCK OFFERING

2021 COMMON STOCK OFFERING	3 Months Ended
	Mar. 31, 2021
Equity [Abstract]
2021 COMMON STOCK OFFERING	2021 COMMON STOCK OFFERINGOn February 12, 2021, we completed a public offering of our common stock pursuant to an underwriting agreement (the “Underwriting Agreement”) dated February 9, 2021, between us and B. Riley Securities, Inc., as representative of the several underwriters (the “Underwriters”). At the closing, we issued to the public 29,487,180 shares of our common stock and received gross proceeds of approximately $172.5 million. Net proceeds from the offering were approximately $163.0 million after deducting underwriting discounts and commissions, but before expenses.The net proceeds of the offering were used to make a prepayment towards the balance outstanding under our U.S. Revolving Credit Facility and permanently reduce the commitments under our senior secured credit facilities

LAST OUT TERM LOANS

LAST OUT TERM LOANS	3 Months Ended
	Mar. 31, 2021
Debt Disclosure [Abstract]
LAST OUT TERM LOANS	2021 SENIOR NOTES OFFERING On February 12, 2021, we completed a public offering of $125.0 million aggregate principal amount of our 8.125% senior notes due 2026. The offering was conducted pursuant to an underwriting agreement (the “Notes Underwriting Agreement”) dated February 10, 2021, between us and B. Riley Securities, Inc., as representative of the several underwriters (the “Underwriters”). At the completion, we received gross proceeds of approximately $125.0 million. Net proceeds received were approximately $120.0 million after deducting underwriting discounts and commissions, but before expenses. The Senior Notes were issued in denominations of $25.00 per Senior Note and in integral multiples thereof. In addition to the public offering, we issued $35.0 million of Senior Notes to B. Riley Financial, Inc. in exchange for a deemed prepayment of our existing Last Out Term Loan Tranche A-3 in a concurrent private offering. The components of the Senior Notes are as follows: (in thousands) March 31, 2021 8.125% Senior Notes due 2026 $ 160,000 Unamortized deferred financing costs 4,491 Net debt balance $ 155,509 The Senior Notes are senior unsecured obligations of the Company and rank equally in right of payment with all of the Company’s other existing and future senior unsecured and unsubordinated indebtedness. The Senior Notes bear interest at the rate of 8.125% per annum. Interest on the Senior Notes is payable quarterly in arrears on January 31, April 30, July 31 and October 31 of each year, commencing on April 30, 2021. The Senior Notes will mature on February 28, 2026. We may, at our option, at any time and from time to time, redeem the Senior Notes for cash in whole or in part (i) on or after February 28, 2022 and prior to February 28, 2023, at a price equal to $25.75 per Senior Note, plus accrued and unpaid interest to, but excluding, the date of redemption, (ii) on or after February 28, 2023 and prior to February 29, 2024, at a price equal to $25.50 per Senior Note, plus accrued and unpaid interest to, but excluding, the date of redemption, (iii) on or after February 29, 2024 and prior to February 28, 2025, at a price equal to $25.25 per Senior Note, plus accrued and unpaid interest to, but excluding, the date of redemption and (iv) on or after February 28, 2025 and prior to maturity, at a price equal to 100% of their principal amount, plus accrued and unpaid interest to, but excluding, the date of redemption. On and after any redemption date, interest will cease to accrue on the redeemed Senior Notes. The Indenture governing the Senior Notes contains customary events of default and cure provisions. On March 31, 2021, we entered into a sales agreement with B. Riley Securities, Inc., a related party, in which we may sell to or through B. Riley Securities, Inc., from time to time, additional Senior Notes up to an aggregated principal amount of $150.0 million of Senior Notes. The Senior Notes will have the same terms as (other than date of issuance), form a single series of debt securities with and have the same CUSIP number and be fungible with, the Senior Notes issued February 12, 2021, as described above. Senior Notes - Subsequent Event As of May 10, 2021, the Company has sold $10.6 million aggregate principal amount of Senior Notes for $11.0 million gross proceeds related to the March 31, 2021 sales agreement disclosed above. The Company received $10.7 million of net cash proceeds after commission and fees. Exchange Agreement On February 12, 2021, the Company and B. Riley entered into the Exchange Agreement pursuant to which we issued to B. Riley, a related party, $35.0 million aggregate principal amount of Senior Notes in exchange for a deemed prepayment of $35.0 million of our existing Tranche A term loan with B. Riley Financial (the “Exchange”). The components of the Last Out Term Loans by Tranche are as follows: March 31, 2021 (in thousands) A-3 Proceeds (1) $ 61,660 Discount and fees 8,650 Paid-in-kind interest 3,020 Net debt balance $ 73,330 (1) Tranche A-3 proceeds represent the net proceeds after the $39.7 million principal prepayment from the July 2019 Equitization Transactions and a $40.0 million principal repayment in March 2021 December 31, 2020 (in thousands) A-3 A-4 A-6 Total Proceeds (1) $ 101,660 $ 30,000 $ 40,000 $ 171,660 Discount and fees 8,650 — — 8,650 Paid-in-kind interest 3,020 — — 3,020 Net debt balance $ 113,330 $ 30,000 $ 40,000 $ 183,330 (1) Tranche A-3 proceeds represent the net proceeds after the $39.7 million principal prepayment from the July 2019 Equitization Transactions. Last Out Term Loans are incurred under our A&R Credit Agreement and are pari passu with the U.S. Revolving Credit Facility except for certain payment subordination provisions. The Last Out Term Loans are subject to the same representations and warranties, covenants and events of default as the U.S. Revolving Credit Facility. In connection with the effectiveness of the A&R Credit Agreement, the maturity date for the Last Out Term Loans was extended to December 30, 2022. On February 12, 2021, in connection with the Exchange described in Note 13, the interest rate on the remaining Last Out Term Loan Tranche A balances was reduced to 6.625% from 12.0%. Interest expense associated with the Last Out Term Loans is detailed in Note 17. Tranche A-3 Effective with Amendment No. 16 to our previous Amended Credit Agreement, we borrowed $150.0 million face value from B. Riley, a related party, under Tranche A-3. The $141.4 million net proceeds from Tranche A-3 were primarily used to pay the amounts due under the settlement agreements covering certain European B&W Renewable loss projects as described in Note 4, with the remainder used for working capital and general corporate purposes. As part of the Equitization Transactions of July 23, 2019, we prepaid $39.7 million principal of Tranche A-3. Also, on March 4, 2021, effective with A&R Amendment No. 3, we paid down an additional $40.0 million on our existing Tranche A-3. Tranche A-4 On January 31, 2020, effective with Amendment No. 20 to the Amended Credit Agreement, we borrowed $30.0 million face value of the Tranche A-4 from B. Riley, a related party and received net proceeds of $26.3 million after incurring total fees of $3.7 million. On March 4, 2021, effective with A&R Amendment No. 3, we paid down the $30.0 million outstanding on our existing Tranche A-4. Tranche A-5 On January 31, 2020, we entered into Amendment No. 20 to the Amended Credit Agreement. Amendment No. 20 provides an incremental Tranche A-5 to be extended prior to maturity of the Last Out Term Loans under the Amended Credit Agreement in the event certain customer letters of credit are drawn. The terms of Tranche A-5 are the same as the terms for the Tranche A-3 under the Amended Credit Agreement. As of May 13, 2021, no borrowings occurred under Tranche A-5. Tranche A-6 On May 14, 2020, effective with the A&R Credit Agreement, we borrowed $30.0 million face value of the Tranche A-6 from B. Riley, a related party, as described in Note 16. On November 30, 2020, we borrowed an additional $10.0 million face value of the Tranche A-6 pursuant to the terms of the A&R Credit Agreement which required the proceeds to be applied as a permanent reduction of the U.S. Revolving Credit Facility. As described in Note 13, on February 12, 2021, we issued $35.0 million of Senior Notes to B. Riley Financial, Inc. in exchange for a deemed prepayment of our existing Tranche A-6 as part of the Exchange. Also, on March 4, 2021, effective with A&R Amendment No. 3, we paid down the remaining $5.0 million outstanding on our existing Tranche A-6. Tranche A-7

REVOLVING DEBT

REVOLVING DEBT	3 Months Ended
	Mar. 31, 2021
Debt Disclosure [Abstract]
REVOLVING DEBT	REVOLVING DEBT Our revolving debt was comprised of our U.S. Revolving Credit Facility in the U.S.in the amount of $164.3 million as of December 31, 2020. As described below, effective with A&R Amendment No. 3 on March 4, 2021, we can no longer obtain revolving loans under the terms of our A&R Credit Agreement. A&R Credit Agreement On May 11, 2015, we entered into an amended credit agreement with a syndicate of lenders in connection with our spin-off from The Babcock & Wilcox Company (now BWX Technologies, Inc.) which governs the U.S. Revolving Credit Facility and the Last Out Term Loans. Since June 2016, we have entered into a number of waivers and amendments to the credit agreement, including several to avoid default under the financial and other covenants specified in the credit agreement. On May 14, 2020, we entered into the A&R Credit Agreement which refinances and extends the maturity of our U.S. Revolving Credit Facility and Last Out Term Loans. On October 30, 2020, we entered into A&R Amendment No. 1 with Bank of America, N.A. A&R Amendment No. 1, among other matters, (i) provides that, under the A&R Credit Agreement, the "Commitment Reduction Amount" shall be an amount equal to (a) for any "Prepayment Event" relating to a "Recovery Event" (each as defined under the A&R Credit Agreement), 50% of the net cash proceeds with respect to such Prepayment Event, and (b) with respect to any other Prepayment Event under the A&R Credit Agreement, the net cash proceeds with respect to such Prepayment Event, and (ii) establishes new financial covenants for interest coverage ratios and senior leverage ratios. On February 8, 2021, we entered into A&R Amendment No. 2 with Bank of America, N.A., as administrative agent to the lenders under our Amended and Restated Credit Agreement. A&R Amendment No. 2 amends our A&R Credit Agreement to, among other matters, (i) permit the issuance of 8.125% Senior Notes offering described above, (ii) permit the deemed prepayment of $35.0 million of our Last Out Term Loan Tranche A with $35.0 million principal amount of Senior Notes, (iii) provide that 75% of the Senior Notes gross proceeds shall be used to repay outstanding borrowings and permanently reduce the commitments under our senior secured credit facilities, and (iv) provide that $5.0 million of certain previously deferred facility fees will be paid by the Company. On March 4, 2021, we entered into A&R Amendment No. 3 with Bank of America, N.A. A&R Amendment No. 3, among other matters, at the date of effectiveness (i) permits the prepayment of certain term loans, (ii) reduces the revolving credit commitments to $130.0 million and removes the ability to obtain revolving loans under the credit agreement, and (iii) amends certain covenants and conditions to the extension of credit. On March 26, 2021, we entered into A&R Amendment No. 4 with Bank of America, N.A. A&R Amendment No. 4, among other matters, at the date of effectiveness (i) permits the issuance of 8.125% senior notes due 2026 up to an aggregate principle amount of $150.0 million, and (ii) modifies the calculation of the senior leverage ratio. As of March 31, 2021, the future effective minimum interest coverage ratios under our A&R Credit Agreement are as follows: • 0.80:1.00 for the quarter ending June 30, 2021 • 1.00:1.00 for the quarter ending September 30, 2021 • 1.10:1.00 for the quarter ending December 31, 2021 • 1.25:1.00 for the quarter ending March 31, 2022 and the last day of each fiscal quarter ending thereafter As of March 31, 2021, the future effective maximum permitted senior leverage ratios under our A&R Credit Agreement are as follows: • 4.25:1.00 for the quarter ending June 30, 2021 • 3.75:1.00 for the quarter ending September 30, 2021 • 3.00:1.00 for the quarter ending December 31, 2021 • 2.25:1.00 for the quarter ending March 31, 2022 and the last day of each fiscal quarter ending thereafter See Note 25 - Subsequent Events for an additional amendment to the A&R Credit Agreement as of May 10, 2021. U.S. Revolving Credit Facility As of March 31, 2021, effective with Amendment No. 3 to the A&R Credit Agreement described above, the U.S. Revolving Credit Facility provides for an aggregate letters of credit amount of up to $130.0 million. At March 31, 2021, usage under the U.S. Revolving Credit Facility consisted of $22.0 million of financial letters of credit and $82.1 million of performance letters of credit. At March 31, 2021, we had approximately $25.9 million available to meet letter of credit requirements based on our overall facility size. On February 12, 2021, we received gross proceeds of $125.0 million from the 2021 Senior Notes offering. As required by the Company’s U.S. Revolving Credit Facility, 75% of the gross proceeds or $93.8 million received by the Company was applied as a permanent reduction of the U.S. Revolving Credit Facility as of February 12, 2021. Also on February 16, 2021, we prepaid $167.1 million toward the remaining outstanding U.S. Revolving Credit Facility. Letters of Credit, Bank Guarantees and Surety Bonds Certain of our subsidiaries primarily outside of the United States have credit arrangements with various commercial banks and other financial institutions for the issuance of letters of credit and bank guarantees in association with contracting activity. The aggregate value of all such letters of credit and bank guarantees opened outside of the U.S. Revolving Credit Facility as of March 31, 2021 and December 31, 2020 was $60.7 million and $88.5 million, respectively. The aggregate value of the letters of credit provided by the U.S. Revolving Credit Facility backstopping letters of credit or bank guarantees was $18.0 million as of March 31, 2021. Of the letters of credit issued under the U.S. Revolving Credit Facility, $27.3 million are subject to foreign currency revaluation. We have posted surety bonds to support contractual obligations to customers relating to certain contracts. We utilize bonding facilities to support such obligations, but the issuance of bonds under those facilities is typically at the surety's discretion. These bonds generally indemnify customers should we fail to perform our obligations under the applicable contracts. We, and certain of our subsidiaries, have jointly executed general agreements of indemnity in favor of surety underwriters relating to surety bonds those underwriters issue in support of some of our contracting activity. As of March 31, 2021, bonds issued and outstanding under these arrangements in support of contracts totaled approximately $266.4 million. The aggregate value of the letters of credit provided by the U.S. Revolving Credit facility backstopping surety bonds was $34.7 million.

INTEREST EXPENSE AND SUPPLEMENT

INTEREST EXPENSE AND SUPPLEMENTAL CASH FLOW INFORMATION	3 Months Ended
	Mar. 31, 2021
Supplemental Cash Flow Information [Abstract]
INTEREST EXPENSE AND SUPPLEMENTAL CASH FLOW INFORMATION	INTEREST EXPENSE AND SUPPLEMENTAL CASH FLOW INFORMATION Interest expense in our Condensed Consolidated Financial Statements consisted of the following components: Three months ended March 31, (in thousands) 2021 2020 Components associated with borrowings from: Senior Notes $ 1,733 $ — Last Out Term Loans - cash interest 3,513 4,048 U.S. Revolving Credit Facility $ 1,416 $ 4,039 6,662 8,087 Components associated with amortization or accretion of: Senior Notes 1,468 — Last Out Term Loans - discount and financing fees — 2,150 U.S. Revolving Credit Facility - deferred financing fees and commitment fees 4,400 9,035 U.S. Revolving Credit Facility - deferred ticking fee for Amendment 16 — 1,658 5,868 12,843 Other interest expense 1,693 1,161 Total interest expense $ 14,223 $ 22,091 The following table provides a reconciliation of cash, cash equivalents and restricted cash reporting within the Condensed Consolidated Balance Sheets that sum to the total of the same amounts in the Condensed Consolidated Statements of Cash Flows: (in thousands) March 31, 2021 December 31, 2020 March 31, 2020 Held by foreign entities $ 25,169 $ 38,726 $ 27,937 Held by U.S. entities 28,664 18,612 7,447 Cash and cash equivalents of continuing operations 53,833 57,338 35,384 Reinsurance reserve requirements 2,053 4,551 5,779 Restricted foreign accounts — 2,869 3,107 Bank guarantee collateral 2,560 2,665 2,115 Restricted cash and cash equivalents 4,613 10,085 11,001 Total cash, cash equivalents and restricted cash shown in the Condensed Consolidated Statements of Cash Flows $ 58,446 $ 67,423 $ 46,385 The following cash activity is presented as a supplement to our Condensed Consolidated Statements of Cash Flows and is included in Net cash used in activities : Three months ended March 31, (in thousands) 2021 2020 Income tax payments, net $ 1,499 $ 793 Interest payments on our U.S. Revolving Credit Facility $ 5,979 $ 4,150 Interest payments on our Last Out Term Loans 3,560 4,038 Total cash paid for interest $ 9,539 $ 8,188

PROVISION FOR INCOME TAXES

PROVISION FOR INCOME TAXES	3 Months Ended
	Mar. 31, 2021
Income Tax Disclosure [Abstract]
PROVISION FOR INCOME TAXES	PROVISION FOR INCOME TAXES In the three months ended March 31, 2021, income tax expense was $2.8 million, resulting in an effective tax rate of (22.5)%. In the three months ended March 31, 2020, income tax benefit was $0.8 million, resulting in an effective tax rate of 2.4%. For the three months ended March 31, 2020, the Company determined the use of the discrete method was more appropriate than the annual effective tax rate method due to the financial uncertainty of the COVID-19 pandemic. Therefore, the Company applied a permitted exception to the ASC 740-270 rules and recorded the actual income tax expense discretely for the three months ended March 31, 2020. Our effective tax rate for the three months ended March 31, 2021 and 2020 is not reflective of the U.S. statutory rate primarily due to valuation allowances against our net deferred tax assets and discrete items. We have unfavorable discrete items of`$2.5 million for the three months ended March 31, 2021, which primarily represents withholding taxes, and favorable discrete items of $0.5 million for the three months ended March 31, 2020. We are subject to federal income tax in the United States and numerous countries that have statutory tax rates different than the United States federal statutory rate of 21%. The most significant of these foreign operations are located in Canada, Denmark, Germany, Italy, Mexico, Sweden, and the United Kingdom, with effective tax rates ranging between approximately 19% and 30%. We provide for income taxes based on the tax laws and rates in the jurisdictions where we conduct operations. These jurisdictions may have regimes of taxation that vary in both nominal rates and the basis on which these rates are applied. Our consolidated effective income tax rate can vary from period to period due to these variations, changes in jurisdictional mix of our income, and valuation allowances.

CONTINGENCIES

CONTINGENCIES	3 Months Ended
	Mar. 31, 2021
Commitments and Contingencies Disclosure [Abstract]
CONTINGENCIES	CONTINGENCIES Litigation Relating to Boiler Installation and Supply Contract On December 27, 2019, a complaint was filed against Babcock & Wilcox by P.H. Glatfelter Company (“Glatfelter”) in the United States District Court for the Middle District of Pennsylvania, Case No. 1:19-cv-02215-JPW, alleging claims of breach of contract, fraud, negligent misrepresentation, promissory estoppel and unjust enrichment (the “Glatfelter Litigation”). The complaint alleges damages in excess of $58.9 million. On March 16, 2020 we filed a motion to dismiss, and on December 14, 2020 the court issued its order dismissing the fraud and negligent misrepresentation claims and finding that, in the event that parties’ contract is found to be valid, Plaintiffs’ claims for damages will be subject to the contractual cap on liability (defined as the $11.7 million purchase price subject to certain adjustments). On January 11, 2021, we filed our Answer and a Counterclaim for breach of contract, seeking damages in excess of $2.9 million. We intend to continue to vigorously litigate the action. However, given the preliminary stage of the litigation, it is too early to determine if the outcome of the Glatfelter Litigation will have a material adverse impact on our condensed consolidated financial condition, results of operations or cash flows. SEC Investigation The U.S. SEC is conducting a formal investigation of the Company, focusing on the accounting charges and related matters involving the Company's B&W Renewable segment from 2015-2019. The SEC has served multiple subpoenas on the Company for documents. The Company is cooperating with the SEC related to the subpoenas and investigation. The SEC has taken testimony from past and current officers, directors, and employees in addition to also seeking testimony from certain third-parties. It is reasonably possible that the SEC may bring one or more claims against the Company and certain individuals. Due to the stage of the investigation, we are unable to estimate the amount of loss or range of potential loss of any claim. However, there can be no assurance that such claims will not have a material impact on the Company. Stockholder Derivative and Class Action Litigation On April 14, 2020, a putative B&W stockholder (“Plaintiff”) filed a derivative and class action complaint against certain of the Company’s directors (current and former), executives and significant stockholders (“Defendants”) and the Company (as a nominal defendant). The action was filed in the Delaware Court of Chancery and is captioned Parker v. Avril, et al., C.A. No. 2020-0280-PAF ("Stockholder Litigation"). Plaintiff alleges that Defendants, among other things, did not properly discharge their fiduciary duties in connection with the 2019 rights offering and related transactions. The case is currently in discovery. We believe that the outcome of the Stockholder Litigation will not have a material adverse impact on our condensed consolidated financial condition, results of operations or cash flows, net of any insurance coverage. Other Due to the nature of our business, we are, from time to time, involved in routine litigation or subject to disputes or claims related to our business activities, including, among other things: performance or warranty-related matters under our customer and supplier contracts and other business arrangements; and workers' compensation, premises liability and other claims. Based on our prior experience, we do not expect that any of these other litigation proceedings, disputes and claims will have a material adverse effect on our condensed consolidated financial condition, results of operations or cash flows.

COMPREHENSIVE INCOME

COMPREHENSIVE INCOME	3 Months Ended
	Mar. 31, 2021
Equity [Abstract]
COMPREHENSIVE INCOME	COMPREHENSIVE INCOME Gains and losses deferred in accumulated other comprehensive income (loss) ("AOCI") are generally reclassified and recognized in the Condensed Consolidated Statements of Operations once they are realized. The changes in the components of AOCI, net of tax, for the first quarter of 2021 and 2020 were as follows: (in thousands) Currency translation Net unrecognized loss related to benefit plans Total Balance at December 31, 2020 $ (47,575) $ (4,815) $ (52,390) Other comprehensive loss before reclassifications (70) — (70) Reclassified from AOCI to net income (loss) (4,512) 198 (4,314) Net other comprehensive (loss) income (4,582) 198 (4,384) Balance at March 31, 2021 $ (52,157) $ (4,617) $ (56,774) (in thousands) Currency translation Net unrecognized loss related to benefit plans Total Balance at December 31, 2019 $ 5,743 $ (3,817) $ 1,926 Other comprehensive income before reclassifications 2,380 — 2,380 Reclassified from AOCI to net income (loss) — (246) (246) Net other comprehensive income (loss) 2,380 (246) 2,134 Balance at March 31, 2020 $ 8,123 $ (4,063) $ 4,060 The amounts reclassified out of AOCI by component and the affected Condensed Consolidated Statements of Operations line items are as follows (in thousands): AOCI component Line items in the Condensed Consolidated Statements of Operations affected by reclassifications from AOCI Three months ended March 31, 2021 2020 Release of currency translation adjustment with the sale of business Gain on sale of business $ 4,512 $ — Amortization of prior service cost on benefit obligations Benefit plans, net (198) 246 Net income $ 4,314 $ 246

FAIR VALUE MEASUREMENTS

FAIR VALUE MEASUREMENTS	3 Months Ended
	Mar. 31, 2021
Fair Value Disclosures [Abstract]
FAIR VALUE MEASUREMENTS	FAIR VALUE MEASUREMENTS The following tables summarize our financial assets and liabilities carried at fair value, all of which were valued from readily available prices or using inputs based upon quoted prices for similar instruments in active markets (known as "Level 1" and "Level 2" inputs, respectively, in the fair value hierarchy established by the FASB Topic, Fair Value Measurements and Disclosures ). (in thousands) Available-for-sale securities March 31, 2021 Level 1 Level 2 Corporate notes and bonds $ 7,804 $ 7,804 $ — Mutual funds 645 — 645 United States Government and agency securities 4,757 4,757 — Total fair value of available-for-sale securities $ 13,206 $ 12,561 $ 645 (in thousands) Available-for-sale securities December 31, 2020 Level 1 Level 2 Corporate notes and bonds $ 6,139 $ 6,139 $ — Mutual funds 636 — 636 Corporate Stocks 4,168 4,168 — United States Government and agency securities 4,365 4,365 — Total fair value of available-for-sale securities $ 15,308 $ 14,672 $ 636 Available-For-Sale Securities Our investments in available-for-sale securities are presented in other assets on our Condensed Consolidated Balance Sheets with contractual maturities ranging from 0-5 years. Senior Notes On February 12, 2021, we completed a Senior Notes offering, as described in Note 13, of $160 million aggregate principal amount of 8.125% Senior Notes due 2026. The fair value of the Senior Notes is based on readily available quoted market prices as of March 31, 2021. (in thousands) March 31, 2021 Senior Notes Carrying Value Estimated Fair Value 8.125% Senior Notes due 2026 ('BWSN') $ 160,000 $ 169,536 Other Financial Instruments We used the following methods and assumptions in estimating our fair value disclosures for our other financial instruments: • Cash and cash equivalents and restricted cash and cash equivalents . The carrying amounts that we have reported in the accompanying Condensed Consolidated Balance Sheets for cash and cash equivalents and restricted cash and cash equivalents approximate their fair values due to their highly liquid nature. • Last Out Term Loans and Revolving Debt . We base the fair values of debt instruments on quoted market prices. Where quoted prices are not available, we base the fair values on Level 2 inputs such as the present value of future cash flows discounted at estimated borrowing rates for similar debt instruments or on estimated prices based on current yields for debt issues of similar quality and terms. The fair value of our Last Out Term Loans approximated their carrying value at March 31, 2021 and December 31, 2020. The fair value of our Revolving Debt approximated their carrying value at December 31, 2020. • Warrants. The fair value of the warrants was established using the Black-Scholes option pricing model value approach.

RELATED PARTY TRANSACTIONS

RELATED PARTY TRANSACTIONS	3 Months Ended
	Mar. 31, 2021
Related Party Transactions [Abstract]
RELATED PARTY TRANSACTIONS	RELATED PARTY TRANSACTIONS Transactions with B. Riley Based on its Schedule 13D filings, B. Riley beneficially owns 33.2% of our outstanding common stock as of March 31, 2021. B. Riley is party to the Last Out Term Loans as described in Note 15. We entered into an agreement with BRPI Executive Consulting, LLC, an affiliate of B. Riley, on November 19, 2018 and amended the agreement on November 9, 2020 to retain the services of Mr. Kenny Young, to serve as our Chief Executive Officer until December 31, 2023, unless terminated by either party with thirty days written notice. Under this agreement, payments are $0.75 million per annum, paid monthly. Subject to the achievement of certain performance objectives as determined by the Compensation Committee of the Board, a bonus or bonuses may also be earned and payable to BRPI Executive Consulting, LLC. Total fees associated with B. Riley related to the Last Out Term Loans and services of Mr. Kenny Young, both as described above, w ere $0.2 million and $4.2 million for the three months ended March 31, 2021 and 2020, respectively. On November 13, 2020 we entered into an agreement with B. Riley Principal Merger Corp. II, an affiliate of B. Riley, to purchase 200,000 shares of Class A common stock of Eos Energy Storage LLC for an aggregate purchase price of $2.0 million. The shares were sold in January 2021 for which the Company recognized net proceeds of $4.5 million. The public offering of our Senior Notes in February 2021, as described in Note 13, was conducted pursuant to an underwriting agreement dated February 10, 2021, between us and B. Riley Securities, Inc., as representative of several underwriters. At the closing date on February 12, 2021, we paid B. Riley Securities, Inc. $5.2 million for underwriting fees and other transaction cost related to the Senior Notes offering. The public offering of our common stock, as described in Note 14, was conducted pursuant to the Underwriting Agreement dated February 9, 2021, between us and B. Riley Securities, Inc., as representative of the several underwriters. Also on February 12, 2021, we paid B. Riley Securities, Inc. $9.5 million for underwriting fees and other transaction costs related to the offering. On February 12, 2021, the Company and B. Riley entered into the Exchange Agreement pursuant to which we agreed to issue to B. Riley $35.0 million aggregate principal amount of Senior Notes in exchange for a deemed prepayment of $35.0 million of our existing Tranche A term loan with B. Riley Financial in the Exchange , as described in Note 13 . On March 31, 2021, we entered into a sales agreement with B. Riley Securities, Inc., a related party, in which we may sell, from time to time, up to an aggregated principal amount of $150.0 million of 8.125% senior notes due 2026 to or through B. Riley Securities, Inc., as described in Note 13 . Refer to Note 25 for additional related party transactions with B. Riley and its affiliates regarding the subsequent events in conjunction with the public offering of the 7.75% Series A Cumulative Perpetual Preferred Stock between the Company and B. Riley Securities, Inc., as representative of the several underwriters. Transactions with Vintage Capital Management, LLC On March 26, 2021, Vintage and B. Riley completed a transaction pursuant to which B. Riley agreed to purchase from Vintage, and Vintage agreed to sell to B. Riley, all 10,720,785 shares of our common stock owned by Vintage. Based on its Schedule 13D filings, Vintage beneficially owns 0% of our outstanding common stock as of March 31, 2021.

ASSETS HELD FOR SALE, DIVESTITU

ASSETS HELD FOR SALE, DIVESTITURES AND DISCONTINUED OPERATIONS	3 Months Ended
	Mar. 31, 2021
Business Combinations [Abstract]
ASSETS HELD FOR SALE, DIVESTITURES AND DISCONTINUED OPERATIONS	ASSETS HELD FOR SALE, DIVESTITURES AND DISCONTINUED OPERATIONS Assets Held for Sale Certain fixed assets for the Copley, Ohio location were sold on March 15, 2021 for $4.0 million. We received $3.3 million of net proceeds after adjustments and recognized a gain on sale of $1.9 million. In conjunction with the sale, we executed a leaseback agreement commencing March 16, 2021 and expiring on March 31, 2033. In December 2019, we determined that a small business within the B&W Thermal segment met the criteria to be classified as held for sale. At December 31, 2020, the carrying value of the net assets planned to be sold approximated the estimated fair value less costs to sell. Refer to Divestiture s below as this sale closed March 5, 2021. The following table summarizes the carrying value of the assets and liabilities held for sale at March 31, 2021 and December 31, 2020: (in thousands) March 31, 2021 December 31, 2020 Accounts receivable – trade, net $ — $ 2,103 Accounts receivable – other — 86 Contracts in progress — 458 Inventories — 1,676 Other current assets — 405 Current assets held for sale — 4,728 Net property, plant and equipment 1,870 10,365 Intangible assets — 759 Right-of-use-asset — 32 Non-current assets held for sale 1,870 11,156 Total assets held for sale $ 1,870 $ 15,884 Accounts payable $ — $ 5,211 Accrued employee benefits — 178 Advance billings on contracts — 370 Accrued warranty expense — 466 Operating lease liabilities — 32 Other accrued liabilities — 2,048 Current liabilities held for sale — 8,305 Total liabilities held for sale $ — $ 8,305 Divestitures Effective March 5, 2021, we sold all of the issued and outstanding capital stock of Diamond Power Machine (Hubei) Co., Inc, to BPE Clyde Pte Ltd. for $2.8 million. We received $2.0 million in gross proceeds before expenses and recorded an $0.8 million favorable contract asset for the amortization period from March 8, 2021 through December 31, 2023. We recognized a $0.4 million pre-tax gain, inclusive of the recognition of $4.5 million of CTA, on the sale of the business in the three months ended March 31, 2021. On March 17, 2020, we fully settled the remaining escrow associated with the sale of PBRRC and received $4.5 million in cash. Discontinued Operations On April 6, 2020, we fully settled the remaining escrow associated with the sale of the MEGTEC and Universal businesses and received $3.5 million in cash.

NEW ACCOUNTING STANDARDS

NEW ACCOUNTING STANDARDS	3 Months Ended
	Mar. 31, 2021
Accounting Policies [Abstract]
NEW ACCOUNTING STANDARDS	NEW ACCOUNTING STANDARDS We adopted the following accounting standard during the first quarter of 2021: In December 2019, the FASB issued ASU 2019-12, Income Taxes (Topic 740): Simplifying the Accounting for Income Taxes. The amendments in this update simplify the accounting for income taxes by removing exceptions related to the incremental approach for intra-period tax allocation, certain deferred tax liabilities, and the general methodology for calculating income taxes in an interim period. The amendment also provides simplification related to accounting for franchise (or similar) tax, evaluating the tax basis step up of goodwill, allocation of consolidated current and deferred tax expense, reflection of the impact of enacted tax law or rate changes in annual effective tax rate calculations in the interim period that includes enactment date, and other minor codification improvements. The impact of this standard on our condensed consolidated financial statements was immaterial. New accounting standards not yet adopted that could affect our Condensed Consolidated Financial Statements in the future are summarized as follows: In March 2021, the FASB issued ASU 2021-01, Reference Rate Reform (Topic 848): Scope. The amendments in this update clarify that certain optional expedients and exceptions in Topic 848 for contract modifications and hedge accounting apply to derivatives that are affected by the discounting transition. This update is an amendment to ASU 2020-04, Reference Rate Reform (Topic 848): Facilitation of the Effects of Reference Rate Reform of Financial Reporting, which was issued in March 2020 and provides optional expedients and exceptions for applying generally accepted accounting principles to contracts, hedging relationships, and other transactions affected by reference rate reform if certain criteria are met. The amendments in the updates apply only to contracts, hedging relationships, and other transactions that reference LIBOR or another reference rate expected to be discontinued because of reference rate reform. The expedients and exceptions provided by the updates do not apply to contract modifications made and hedging relationships entered into or evaluated after December 31, 2022, except for hedging relationships existing as of December 31, 2022, that an entity has elected certain optional expedients for and that are retained through the end of the hedging relationship. The amendments in both updates are effective for all entities upon issuance and may be adopted any date on or after March 12, 2020 up to December 31, 2022. We are currently evaluating the impact of the standards on our condensed consolidated financial statements. In August 2020, the FASB issued ASU 2020-06, Debt – Debt with Conversion and Other Options (Subtopic 470-20) and Derivatives and Hedging – Contracts in Entity’s Own Equity (Subtopic 815 – 40) . The amendments in this update simplify the accounting for certain financial instruments with characteristics of liabilities and equity, including convertible instruments and contracts on an entity’s own equity by removing major separation models required under current U.S. GAAP. The amendments also improve the consistency of diluted earnings per share calculations. The amendments in this update are effective for public business entities that meet the definition of an SEC filer, excluding entities eligible to be smaller reporting companies as defined by the SEC, for fiscal years beginning after December 15, 2021, including interim periods within those fiscal years. For all other entities, the amendments are effective for fiscal years beginning after December 15, 2023, including interim periods within those fiscal years. Early adoption is permitted, but no earlier than fiscal years beginning after December 15, 2020, including interim periods within those fiscal years. We are currently evaluating the impact of the standard on our condensed consolidated financial statements. In November 2018, the FASB issued ASU 2018-19, Codification Improvements to Topic 326: Financial Instruments - Credit Losses. This update is an amendment to the new credit losses standard, ASU 2016-13, Financial Instruments—Credit Losses (Topic 326): Measurement of Credit Losses on Financial Instruments , that was issued in June 2016 and clarifies that operating lease receivables are not within the scope of Topic 326. The new credit losses standard changes the accounting for credit losses for certain instruments. The new measurement approach is based on expected losses, commonly referred to as the current expected credit loss (CECL) model, and applies to financial assets measured at amortized cost, including loans, held-to-maturity debt securities, net investment in leases, and reinsurance and trade receivables, as well as certain off-balance sheet credit exposures, such as loan commitments. The standard also changes the impairment model for available-for-sale debt securities. The provisions of this standard will primarily impact the allowance for doubtful accounts on our trade receivables, contracts in progress, and potentially our impairment model for available-for-sale debt securities (to the extent we have any upon adoption). For public, smaller reporting companies, this standard is effective for fiscal years beginning after December 15, 2022, including interim periods within those fiscal years. We are currently evaluating the impact of both standards on our condensed consolidated financial statements.

SUBSEQUENT EVENTS

SUBSEQUENT EVENTS	3 Months Ended
	Mar. 31, 2021
Subsequent Events [Abstract]
SUBSEQUENT EVENTS	SUBSEQUENT EVENTS 2021 Preferred Stock Offerings On May 7, 2021, we completed a public offering of our 7.75% Series A Cumulative Perpetual Preferred Stock (the "Preferred Stock") pursuant to an underwriting agreement (the “Underwriting Agreement”) dated May 4, 2021, between us and B. Riley Securities, Inc., as representative of the several underwriters (the “Underwriters”). At the closing, we issued to the public 4,000,000 shares of our Preferred Stock, at an offering price of $25.00 per share for gross proceeds of approximately $100.0 million before deducting underwriting discounts, commissions and estimated offering expenses. We have granted the underwriters a 30-day option to purchase up to an additional 600,000 shares of the Preferred Stock in connection with the offering. Net proceeds from the offering were approximately $95.7 million after deducting underwriting discounts, commissions but before expenses. The Preferred Stock has a par value of $0.01 per share and is perpetual and has no maturity date. The Preferred Stock has a cumulative cash dividend, when and as if declared by our Board of Directors, at a rate of 7.75% per year on the liquidation preference amount of $25.00 per share and payable quarterly in arrears. The Preferred Stock will, as to dividend rights and rights as to the distribution of assets upon our liquidation, dissolution or winding-up, rank: (1) senior to all classes or series of our common stock and to all other capital stock issued by us expressly designated as ranking junior to the Preferred Stock; (2) on parity with any future class or series of our capital stock expressly designated as ranking on parity with the Preferred Stock; (3) junior to any future class or series of our capital stock expressly designated as ranking senior to the Preferred Stock; and (4) junior to all our existing and future indebtedness. The Preferred Stock has no stated maturity and is not subject to mandatory redemption or any sinking fund. We will pay cumulative cash dividends on the Preferred Stock when, as and if declared by our Board of Directors (or a duly authorized committee of our Board of Directors), only out of funds legally available for payment of dividends. Dividends on the Preferred Stock will accrue on the stated amount of $25.00 per share of the Preferred Stock at a rate per annum equal to 7.75% (equivalent to $1.9375 per year), payable quarterly in arrears. Dividends on the Series A Preferred Stock declared by our board of directors (or a duly authorized committee of our board of directors) will be payable quarterly in arrears on March 31, June 30, September 30 and December 31, beginning on June 30, 2021. The net proceeds of the offering are intended to be used for general corporate purposes, including clean energy growth initiatives, potential future acquisitions and reduction of net leverage. The Preferred Stock is expected to begin trading on the NYSE under the symbol “BW PRA” within 30 business days of the closing date. Revolving Debt - A&R Credit Agreement On May 10, 2021, we entered into Amendment No. 5 to Amended and Restated Credit Agreement with Bank of America, N.A., in its capacity as administrative agent (“A&R Amendment No. 5”). A&R Amendment No. 5 amends the terms of our A&R Credit Agreement to, among other matters, (i) permit the payment of dividends on the Preferred Stock and (ii) permit certain future issuances of Preferred Stock to B. Riley, a related party, in exchange for deemed prepayments of amounts outstanding under our A&R Credit Agreement.

NEW ACCOUNTING STANDARDS (Polic

NEW ACCOUNTING STANDARDS (Policies)	3 Months Ended
	Mar. 31, 2021
Accounting Policies [Abstract]
New accounting standards	We adopted the following accounting standard during the first quarter of 2021: In December 2019, the FASB issued ASU 2019-12, Income Taxes (Topic 740): Simplifying the Accounting for Income Taxes. The amendments in this update simplify the accounting for income taxes by removing exceptions related to the incremental approach for intra-period tax allocation, certain deferred tax liabilities, and the general methodology for calculating income taxes in an interim period. The amendment also provides simplification related to accounting for franchise (or similar) tax, evaluating the tax basis step up of goodwill, allocation of consolidated current and deferred tax expense, reflection of the impact of enacted tax law or rate changes in annual effective tax rate calculations in the interim period that includes enactment date, and other minor codification improvements. The impact of this standard on our condensed consolidated financial statements was immaterial. New accounting standards not yet adopted that could affect our Condensed Consolidated Financial Statements in the future are summarized as follows: In March 2021, the FASB issued ASU 2021-01, Reference Rate Reform (Topic 848): Scope. The amendments in this update clarify that certain optional expedients and exceptions in Topic 848 for contract modifications and hedge accounting apply to derivatives that are affected by the discounting transition. This update is an amendment to ASU 2020-04, Reference Rate Reform (Topic 848): Facilitation of the Effects of Reference Rate Reform of Financial Reporting, which was issued in March 2020 and provides optional expedients and exceptions for applying generally accepted accounting principles to contracts, hedging relationships, and other transactions affected by reference rate reform if certain criteria are met. The amendments in the updates apply only to contracts, hedging relationships, and other transactions that reference LIBOR or another reference rate expected to be discontinued because of reference rate reform. The expedients and exceptions provided by the updates do not apply to contract modifications made and hedging relationships entered into or evaluated after December 31, 2022, except for hedging relationships existing as of December 31, 2022, that an entity has elected certain optional expedients for and that are retained through the end of the hedging relationship. The amendments in both updates are effective for all entities upon issuance and may be adopted any date on or after March 12, 2020 up to December 31, 2022. We are currently evaluating the impact of the standards on our condensed consolidated financial statements. In August 2020, the FASB issued ASU 2020-06, Debt – Debt with Conversion and Other Options (Subtopic 470-20) and Derivatives and Hedging – Contracts in Entity’s Own Equity (Subtopic 815 – 40) . The amendments in this update simplify the accounting for certain financial instruments with characteristics of liabilities and equity, including convertible instruments and contracts on an entity’s own equity by removing major separation models required under current U.S. GAAP. The amendments also improve the consistency of diluted earnings per share calculations. The amendments in this update are effective for public business entities that meet the definition of an SEC filer, excluding entities eligible to be smaller reporting companies as defined by the SEC, for fiscal years beginning after December 15, 2021, including interim periods within those fiscal years. For all other entities, the amendments are effective for fiscal years beginning after December 15, 2023, including interim periods within those fiscal years. Early adoption is permitted, but no earlier than fiscal years beginning after December 15, 2020, including interim periods within those fiscal years. We are currently evaluating the impact of the standard on our condensed consolidated financial statements. In November 2018, the FASB issued ASU 2018-19, Codification Improvements to Topic 326: Financial Instruments - Credit Losses. This update is an amendment to the new credit losses standard, ASU 2016-13, Financial Instruments—Credit Losses (Topic 326): Measurement of Credit Losses on Financial Instruments , that was issued in June 2016 and clarifies that operating lease receivables are not within the scope of Topic 326. The new credit losses standard changes the accounting for credit losses for certain instruments. The new measurement approach is based on expected losses, commonly referred to as the current expected credit loss (CECL) model, and applies to financial assets measured at amortized cost, including loans, held-to-maturity debt securities, net investment in leases, and reinsurance and trade receivables, as well as certain off-balance sheet credit exposures, such as loan commitments. The standard also changes the impairment model for available-for-sale debt securities. The provisions of this standard will primarily impact the allowance for doubtful accounts on our trade receivables, contracts in progress, and potentially our impairment model for available-for-sale debt securities (to the extent we have any upon adoption). For public, smaller reporting companies, this standard is effective for fiscal years beginning after December 15, 2022, including interim periods within those fiscal years. We are currently evaluating the impact of both standards on our condensed consolidated financial statements.

EARNINGS PER SHARE (Tables)

EARNINGS PER SHARE (Tables)	3 Months Ended
	Mar. 31, 2021
Earnings Per Share [Abstract]
Computation of Basic and Diluted Earnings Per Share	The following table sets forth the computation of basic and diluted earnings per share of our common stock, net of non-controlling interest: Three months ended March 31, (in thousands, except per share amounts) 2021 2020 Loss from continuing operations $ (15,464) $ (33,439) Income from discontinued operations, net of tax — 1,913 Net loss attributable to stockholders $ (15,464) $ (31,526) Weighted average shares used to calculate basic and diluted earnings (loss) per share 71,396 46,403 Basic and diluted (loss) earnings per share Continuing operations $ (0.22) $ (0.72) Discontinued operations — 0.04 Basic and diluted loss per share $ (0.22) $ (0.68)

SEGMENT REPORTING (Tables)

SEGMENT REPORTING (Tables)	3 Months Ended
	Mar. 31, 2021
Segment Reporting [Abstract]
Schedule of Segment Reporting Information, by Segment	An analysis of our operations by segment is as follows: Three months ended March 31, (in thousands) 2021 2020 Revenues: B&W Renewable segment B&W Renewable $ 17,997 $ 22,338 Vølund 10,814 13,661 28,811 35,999 B&W Environmental segment B&W Environmental 17,433 12,935 SPIG 11,184 11,337 GMAB 2,543 1,648 31,160 25,920 B&W Thermal segment B&W Thermal 108,281 86,683 108,281 86,683 Other (4) (48) $ 168,248 $ 148,554 Adjusted EBITDA for each segment is presented below with a reconciliation to net income (loss) attributable to stockholders. Three months ended March 31, (in thousands) 2021 2020 Adjusted EBITDA (1) B&W Renewable segment $ 204 $ (1,434) B&W Environmental segment 1,101 270 B&W Thermal segment 10,430 7,606 Corporate (2,685) (4,143) Research and development costs (588) (1,341) 8,462 958 Restructuring activities (993) (1,951) Financial advisory services (933) (929) Advisory fees for settlement costs and liquidity planning (1,978) (2,614) Litigation legal costs (380) (696) Stock compensation (7,829) (712) Interest on letters of credit included in cost of operations (286) (152) Loss from business held for sale (483) (788) Depreciation & amortization (4,058) (4,208) Gain (loss) from a non-strategic business 12 (121) Gain on asset disposals, net 2,004 915 Operating loss (6,462) (10,298) Interest expense, net (14,114) (22,051) Gain on sale of business 358 — Net pension benefit 9,098 7,536 Foreign exchange (1,209) (9,326) Other – net (278) (206) Total other income (expense) (6,145) (24,047) Loss before income tax (benefit) expense (12,607) (34,345) Income tax (benefit) expense 2,836 (810) Loss from continuing operations (15,443) (33,535) Income from discontinued operations, net of tax — 1,913 Net loss (15,443) (31,622) Net (income) loss attributable to non-controlling interest (21) 96 Net loss attributable to stockholders $ (15,464) $ (31,526) (1) Adjusted EBITDA for the three months ended March 31, 2020, excludes losses related to a non-strategic business and interest on letters of credit included in cost of operations that were previously included in Adjusted EBITDA and total $(0.1) million and $(0.2) million, respectively.

REVENUE RECOGNITION AND CONTR_2

REVENUE RECOGNITION AND CONTRACTS (Tables)	3 Months Ended
	Mar. 31, 2021
Revenue from Contract with Customer [Abstract]
Schedule of Contracts in Progress and Advance Billings on Contracts	The following represents the components of our contracts in progress and advance billings on contracts included in our Condensed Consolidated Balance Sheets: (in thousands) March 31, 2021 December 31, 2020 $ Change % Change Contract assets - included in contracts in progress: Costs incurred less costs of revenue recognized $ 27,096 $ 25,888 $ 1,208 5 % Revenues recognized less billings to customers 39,137 33,420 5,717 17 % Contracts in progress $ 66,233 $ 59,308 $ 6,925 12 % Contract liabilities - included in advance billings on contracts: Billings to customers less revenues recognized $ 80,328 $ 61,884 $ 18,444 30 % Costs of revenue recognized less cost incurred 1,425 2,118 (693) (33) % Advance billings on contracts $ 81,753 $ 64,002 $ 17,751 28 % Net contract balance $ (15,520) $ (4,694) $ (10,826) 231 % Accrued contract losses $ 453 $ 582 $ (129) (22) %
Schedule of Recognized Changes in Estimated Gross Profit	In the three months ended March 31, 2021 and 2020, we recognized changes in estimated gross profit related to long-term contracts accounted for on the over time basis, which are summarized as follows: Three months ended March 31, (in thousands) 2021 2020 Increases in gross profit for changes in estimates for over time contracts $ 3,025 $ 8,182 Decreases in gross profit for changes in estimates for over time contracts (1,358) (4,845) Net changes in gross profit for changes in estimates for over time contracts $ 1,667 $ 3,337

INVENTORIES (Tables)

INVENTORIES (Tables)	3 Months Ended
	Mar. 31, 2021
Inventory Disclosure [Abstract]
Schedule of Components of Inventories	The components of inventories are as follows: (in thousands) March 31, 2021 December 31, 2020 Raw materials and supplies $ 46,851 $ 46,659 Work in progress 8,460 8,195 Finished goods 12,553 12,307 Total inventories $ 67,864 $ 67,161

PROPERTY, PLANT & EQUIPMENT, _2

PROPERTY, PLANT & EQUIPMENT, & FINANCE LEASE (Tables)	3 Months Ended
	Mar. 31, 2021
Property, Plant and Equipment [Abstract]
Property, Plant and Equipment and Finance Lease	Property, plant and equipment less accumulated depreciation is as follows: (in thousands) March 31, 2021 December 31, 2020 Land $ 1,533 $ 1,584 Buildings 33,902 34,207 Machinery and equipment 150,605 151,399 Property under construction 5,182 5,336 191,222 192,526 Less accumulated depreciation 137,025 135,925 Net property, plant and equipment 54,197 56,601 Finance lease 34,254 30,551 Less finance lease accumulated amortization 2,603 2,074 Net property, plant and equipment, and finance lease $ 85,848 $ 85,078

GOODWILL (Tables)

GOODWILL (Tables)	3 Months Ended
	Mar. 31, 2021
Goodwill and Intangible Assets Disclosure [Abstract]
Schedule of Goodwill	The following summarizes the changes in the net carrying amount of goodwill as of March 31, 2021: (in thousands) B&W Renewable B&W Environmental B&W Thermal Total Balance at December 31, 2020 $ 10,211 $ 5,673 $ 31,479 $ 47,363 Currency translation adjustments (1) (1) (7) (9) Balance at March 31, 2021 $ 10,210 $ 5,672 $ 31,472 $ 47,354

INTANGIBLE ASSETS (Tables)

INTANGIBLE ASSETS (Tables)	3 Months Ended
	Mar. 31, 2021
Goodwill and Intangible Assets Disclosure [Abstract]
Schedule of Intangible Assets	Our intangible assets are as follows: (in thousands) March 31, 2021 December 31, 2020 Definite-lived intangible assets Customer relationships $ 24,102 $ 24,862 Unpatented technology 15,321 15,713 Patented technology 3,114 2,642 Tradename 12,769 13,088 All other 9,418 9,262 Gross value of definite-lived intangible assets 64,724 65,567 Customer relationships amortization (19,762) (19,537) Unpatented technology amortization (7,149) (6,751) Patented technology amortization (2,616) (2,593) Tradename amortization (4,978) (4,831) All other amortization (9,315) (9,252) Accumulated amortization (43,820) (42,964) Net definite-lived intangible assets $ 20,904 $ 22,603 Indefinite-lived intangible assets Trademarks and trade names $ 1,305 $ 1,305 Total intangible assets, net $ 22,209 $ 23,908
Schedule of Finite-Lived Intangible Assets	The following summarizes the changes in the carrying amount of intangible assets: Three months ended March 31, (in thousands) 2021 2020 Balance at beginning of period $ 23,908 $ 25,300 Amortization expense (856) (895) Currency translation adjustments (843) (73) Balance at end of the period $ 22,209 $ 24,332
Schedule of Indefinite-Lived Intangible Assets	The following summarizes the changes in the carrying amount of intangible assets: Three months ended March 31, (in thousands) 2021 2020 Balance at beginning of period $ 23,908 $ 25,300 Amortization expense (856) (895) Currency translation adjustments (843) (73) Balance at end of the period $ 22,209 $ 24,332
Schedule of Estimated Future Intangible Asset Amortization Expense	Estimated future intangible asset amortization expense is as follows (in thousands): Amortization Expense Year ending December 31, 2021 $ 2,470 Year ending December 31, 2022 3,321 Year ending December 31, 2023 3,319 Year ending December 31, 2024 3,247 Year ending December 31, 2025 2,549 Year ending December 31, 2026 1,292 Thereafter 4,706

LEASES (Tables)

LEASES (Tables)	3 Months Ended
	Mar. 31, 2021
Leases [Abstract]
Components of Lease Cost	The components of lease expense included on our Condensed Consolidated Statements of Operations were as follows: Three months ended March 31, (in thousands) Classification 2021 2020 Operating lease expense: Operating lease expense Selling, general and administrative expenses $ 1,339 $ 1,507 Short-term lease expense Selling, general and administrative expenses 1,155 188 Variable lease expense (1) Selling, general and administrative expenses 208 776 Total operating lease expense $ 2,702 $ 2,471 Finance lease expense: Amortization of right-of-use assets Selling, general and administrative expenses $ 529 $ 515 Interest on lease liabilities Interest expense 616 615 Total finance lease expense $ 1,145 $ 1,130 Sublease income (2) Other – net $ (22) $ (22) Net lease cost $ 3,825 $ 3,579 (1) Variable lease expense primarily consists of common area maintenance expenses paid directly to lessors of real estate leases. (2) Sublease income excludes rental income from owned properties, which is not material. Other information related to leases is as follows: Three months ended March 31, (in thousands) 2021 2020 Cash paid for amounts included in the measurement of lease liabilities: Operating cash flows from operating leases $ 1,355 $ 1,400 Operating cash flows from finance leases 616 615 Financing cash flows from finance leases 203 (586) March 31, 2021 December 31, 2020 Right-of-use assets obtained in exchange for lease liabilities: Operating leases $ 491 $ 2,629 Finance leases $ 3,702 $ 146 Weighted-average remaining lease term: Operating leases (in years) 3.0 3.1 Finance leases (in years) 13.5 13.9 Weighted-average discount rate: Operating leases 9.28 % 9.26 % Finance leases 7.92 % 8.00 %
Supplemental Balance Sheet Information	Amounts relating to leases were presented on our Condensed Consolidated Balance Sheets in the following line items: (in thousands) Assets: Classification March 31, 2021 December 31, 2020 Operating lease assets Right-of-use assets $ 9,513 $ 10,814 Finance lease assets Net property, plant and equipment, and finance lease 31,651 28,477 Total non-current lease assets $ 41,164 $ 39,291 Liabilities: Current Operating lease liabilities Operating lease liabilities $ 3,578 $ 3,995 Finance lease liabilities Other accrued liabilities 920 886 Non-current Operating lease liabilities Non-current operating lease liabilities 6,137 7,031 Finance lease liabilities Non-current finance lease liabilities 33,155 29,690 Total lease liabilities $ 43,790 $ 41,602
Finance Lease Maturity	Future minimum lease payments required under non-cancellable leases as of March 31, 2021 were as follows: (in thousands) Operating Leases Finance Leases Total 2021 (excluding the three months ended March 31, 2021) $ 3,467 $ 2,629 $ 6,096 2022 3,439 3,793 7,232 2023 2,407 3,879 6,286 2024 1,326 3,944 5,270 2025 313 3,969 4,282 Thereafter 19 38,412 38,431 Total $ 10,971 $ 56,626 $ 67,597 Less imputed interest (1,256) (22,551) (23,807) Lease liability $ 9,715 $ 34,075 $ 43,790
Operating Lease Maturity	Future minimum lease payments required under non-cancellable leases as of March 31, 2021 were as follows: (in thousands) Operating Leases Finance Leases Total 2021 (excluding the three months ended March 31, 2021) $ 3,467 $ 2,629 $ 6,096 2022 3,439 3,793 7,232 2023 2,407 3,879 6,286 2024 1,326 3,944 5,270 2025 313 3,969 4,282 Thereafter 19 38,412 38,431 Total $ 10,971 $ 56,626 $ 67,597 Less imputed interest (1,256) (22,551) (23,807) Lease liability $ 9,715 $ 34,075 $ 43,790

ACCRUED WARRANTY EXPENSE (Table

ACCRUED WARRANTY EXPENSE (Tables)	3 Months Ended
	Mar. 31, 2021
Product Warranties Disclosures [Abstract]
Schedule of Changes in Carrying Amount of Accrued Warranty Expense	Changes in the carrying amount of our accrued warranty expense are as follows: Three months ended March 31, (in thousands) 2021 2020 Balance at beginning of period $ 25,399 $ 33,376 Additions 1,475 1,350 Expirations and other changes (1,318) (517) Payments (5,943) (3,119) Translation and other (76) (137) Balance at end of period $ 19,537 $ 30,953

RESTRUCTURING ACTIVITIES (Table

RESTRUCTURING ACTIVITIES (Tables)	3 Months Ended
	Mar. 31, 2021
Restructuring and Related Activities [Abstract]
Summary of Restructuring Activity	The following table summarizes the restructuring activity incurred by segment: Three months ended March 31, Three months ended March 31, 2021 2020 (in thousands) Total Severance and related costs Other (1) Total Severance and related costs Other (1) B&W Renewable segment $ 509 $ 453 $ 56 $ 801 $ 658 $ 143 B&W Environmental segment 89 35 54 140 57 83 B&W Thermal segment 348 12 336 941 386 555 Corporate 47 — 47 69 — 69 $ 993 $ 500 $ 493 $ 1,951 $ 1,101 $ 850 Total Severance and related costs Other (1) Cumulative costs to date $ 41,307 33,713 7,594
Activity Related to the Restructuring Liabilities	Activity related to the restructuring liabilities is as follows: Three months ended March 31, (in thousands) 2021 2020 Balance at beginning of period $ 8,146 $ 5,358 Restructuring expense 993 1,951 Payments (1,117) (1,968) Balance at end of period $ 8,022 $ 5,341

PENSION PLANS AND OTHER POSTR_2

PENSION PLANS AND OTHER POSTRETIREMENT BENEFITS (Tables)	3 Months Ended
	Mar. 31, 2021
Retirement Benefits [Abstract]
Schedule of Net Benefit Costs	Components of net periodic benefit cost (benefit) included in net income (loss) are as follows: Pension Benefits Other Benefits Three months ended March 31, Three months ended March 31, (in thousands) 2021 2020 2021 2020 Interest cost $ 5,671 $ 8,261 $ 39 $ 72 Expected return on plan assets (15,009) (15,641) — — Amortization of prior service cost (credit) 28 43 173 (271) Benefit plans, net (1) (9,310) (7,337) 212 (199) Service cost included in COS (2) 217 211 6 5 Net periodic benefit cost (benefit) $ (9,093) $ (7,126) $ 218 $ (194) (1) Benefit plans, net , which is presented separately in the Condensed Consolidated Statements of Operations, is not allocated to the segments. (2) Service cost related to a small group of active participants is presented within cost of operations in the Condensed Consolidated Statement of Operations and is allocated to the B&W Thermal segment.

2021 SENIOR NOTES OFFERING (Tab

2021 SENIOR NOTES OFFERING (Tables)	3 Months Ended
	Mar. 31, 2021
Debt Disclosure [Abstract]
Components of The Senior Notes	The components of the Senior Notes are as follows: (in thousands) March 31, 2021 8.125% Senior Notes due 2026 $ 160,000 Unamortized deferred financing costs 4,491 Net debt balance $ 155,509 The components of the Last Out Term Loans by Tranche are as follows: March 31, 2021 (in thousands) A-3 Proceeds (1) $ 61,660 Discount and fees 8,650 Paid-in-kind interest 3,020 Net debt balance $ 73,330 (1) Tranche A-3 proceeds represent the net proceeds after the $39.7 million principal prepayment from the July 2019 Equitization Transactions and a $40.0 million principal repayment in March 2021 December 31, 2020 (in thousands) A-3 A-4 A-6 Total Proceeds (1) $ 101,660 $ 30,000 $ 40,000 $ 171,660 Discount and fees 8,650 — — 8,650 Paid-in-kind interest 3,020 — — 3,020 Net debt balance $ 113,330 $ 30,000 $ 40,000 $ 183,330 (1) Tranche A-3 proceeds represent the net proceeds after the $39.7 million principal prepayment from the July 2019 Equitization Transactions.

LAST OUT TERM LOANS (Tables)

LAST OUT TERM LOANS (Tables)	3 Months Ended
	Mar. 31, 2021
Debt Disclosure [Abstract]
Schedule of Debt	The components of the Senior Notes are as follows: (in thousands) March 31, 2021 8.125% Senior Notes due 2026 $ 160,000 Unamortized deferred financing costs 4,491 Net debt balance $ 155,509 The components of the Last Out Term Loans by Tranche are as follows: March 31, 2021 (in thousands) A-3 Proceeds (1) $ 61,660 Discount and fees 8,650 Paid-in-kind interest 3,020 Net debt balance $ 73,330 (1) Tranche A-3 proceeds represent the net proceeds after the $39.7 million principal prepayment from the July 2019 Equitization Transactions and a $40.0 million principal repayment in March 2021 December 31, 2020 (in thousands) A-3 A-4 A-6 Total Proceeds (1) $ 101,660 $ 30,000 $ 40,000 $ 171,660 Discount and fees 8,650 — — 8,650 Paid-in-kind interest 3,020 — — 3,020 Net debt balance $ 113,330 $ 30,000 $ 40,000 $ 183,330 (1) Tranche A-3 proceeds represent the net proceeds after the $39.7 million principal prepayment from the July 2019 Equitization Transactions.

INTEREST EXPENSE AND SUPPLEME_2

INTEREST EXPENSE AND SUPPLEMENTAL CASH FLOW INFORMATION (Tables)	3 Months Ended
	Mar. 31, 2021
Supplemental Cash Flow Information [Abstract]
Summary of Interest Expenses	Interest expense in our Condensed Consolidated Financial Statements consisted of the following components: Three months ended March 31, (in thousands) 2021 2020 Components associated with borrowings from: Senior Notes $ 1,733 $ — Last Out Term Loans - cash interest 3,513 4,048 U.S. Revolving Credit Facility $ 1,416 $ 4,039 6,662 8,087 Components associated with amortization or accretion of: Senior Notes 1,468 — Last Out Term Loans - discount and financing fees — 2,150 U.S. Revolving Credit Facility - deferred financing fees and commitment fees 4,400 9,035 U.S. Revolving Credit Facility - deferred ticking fee for Amendment 16 — 1,658 5,868 12,843 Other interest expense 1,693 1,161 Total interest expense $ 14,223 $ 22,091
Schedule of Cash and Cash Equivalents	The following table provides a reconciliation of cash, cash equivalents and restricted cash reporting within the Condensed Consolidated Balance Sheets that sum to the total of the same amounts in the Condensed Consolidated Statements of Cash Flows: (in thousands) March 31, 2021 December 31, 2020 March 31, 2020 Held by foreign entities $ 25,169 $ 38,726 $ 27,937 Held by U.S. entities 28,664 18,612 7,447 Cash and cash equivalents of continuing operations 53,833 57,338 35,384 Reinsurance reserve requirements 2,053 4,551 5,779 Restricted foreign accounts — 2,869 3,107 Bank guarantee collateral 2,560 2,665 2,115 Restricted cash and cash equivalents 4,613 10,085 11,001 Total cash, cash equivalents and restricted cash shown in the Condensed Consolidated Statements of Cash Flows $ 58,446 $ 67,423 $ 46,385
Schedule of Restricted Cash and Cash Equivalents	The following table provides a reconciliation of cash, cash equivalents and restricted cash reporting within the Condensed Consolidated Balance Sheets that sum to the total of the same amounts in the Condensed Consolidated Statements of Cash Flows: (in thousands) March 31, 2021 December 31, 2020 March 31, 2020 Held by foreign entities $ 25,169 $ 38,726 $ 27,937 Held by U.S. entities 28,664 18,612 7,447 Cash and cash equivalents of continuing operations 53,833 57,338 35,384 Reinsurance reserve requirements 2,053 4,551 5,779 Restricted foreign accounts — 2,869 3,107 Bank guarantee collateral 2,560 2,665 2,115 Restricted cash and cash equivalents 4,613 10,085 11,001 Total cash, cash equivalents and restricted cash shown in the Condensed Consolidated Statements of Cash Flows $ 58,446 $ 67,423 $ 46,385
Schedule of Other Significant Noncash Transactions	The following cash activity is presented as a supplement to our Condensed Consolidated Statements of Cash Flows and is included in Net cash used in activities : Three months ended March 31, (in thousands) 2021 2020 Income tax payments, net $ 1,499 $ 793 Interest payments on our U.S. Revolving Credit Facility $ 5,979 $ 4,150 Interest payments on our Last Out Term Loans 3,560 4,038 Total cash paid for interest $ 9,539 $ 8,188

COMPREHENSIVE INCOME (Tables)

COMPREHENSIVE INCOME (Tables)	3 Months Ended
	Mar. 31, 2021
Equity [Abstract]
Schedule of Accumulated Other Comprehensive Income (Loss)	The changes in the components of AOCI, net of tax, for the first quarter of 2021 and 2020 were as follows: (in thousands) Currency translation Net unrecognized loss related to benefit plans Total Balance at December 31, 2020 $ (47,575) $ (4,815) $ (52,390) Other comprehensive loss before reclassifications (70) — (70) Reclassified from AOCI to net income (loss) (4,512) 198 (4,314) Net other comprehensive (loss) income (4,582) 198 (4,384) Balance at March 31, 2021 $ (52,157) $ (4,617) $ (56,774) (in thousands) Currency translation Net unrecognized loss related to benefit plans Total Balance at December 31, 2019 $ 5,743 $ (3,817) $ 1,926 Other comprehensive income before reclassifications 2,380 — 2,380 Reclassified from AOCI to net income (loss) — (246) (246) Net other comprehensive income (loss) 2,380 (246) 2,134 Balance at March 31, 2020 $ 8,123 $ (4,063) $ 4,060
Reclassification out of Accumulated Other Comprehensive Income	The amounts reclassified out of AOCI by component and the affected Condensed Consolidated Statements of Operations line items are as follows (in thousands): AOCI component Line items in the Condensed Consolidated Statements of Operations affected by reclassifications from AOCI Three months ended March 31, 2021 2020 Release of currency translation adjustment with the sale of business Gain on sale of business $ 4,512 $ — Amortization of prior service cost on benefit obligations Benefit plans, net (198) 246 Net income $ 4,314 $ 246

FAIR VALUE MEASUREMENTS (Tables

FAIR VALUE MEASUREMENTS (Tables)	3 Months Ended
	Mar. 31, 2021
Fair Value Disclosures [Abstract]
Schedule of Fair Value of Financial Assets and Liabilities	The following tables summarize our financial assets and liabilities carried at fair value, all of which were valued from readily available prices or using inputs based upon quoted prices for similar instruments in active markets (known as "Level 1" and "Level 2" inputs, respectively, in the fair value hierarchy established by the FASB Topic, Fair Value Measurements and Disclosures ). (in thousands) Available-for-sale securities March 31, 2021 Level 1 Level 2 Corporate notes and bonds $ 7,804 $ 7,804 $ — Mutual funds 645 — 645 United States Government and agency securities 4,757 4,757 — Total fair value of available-for-sale securities $ 13,206 $ 12,561 $ 645 (in thousands) Available-for-sale securities December 31, 2020 Level 1 Level 2 Corporate notes and bonds $ 6,139 $ 6,139 $ — Mutual funds 636 — 636 Corporate Stocks 4,168 4,168 — United States Government and agency securities 4,365 4,365 — Total fair value of available-for-sale securities $ 15,308 $ 14,672 $ 636

ASSETS HELD FOR SALE, DIVESTI_2

ASSETS HELD FOR SALE, DIVESTITURES AND DISCONTINUED OPERATIONS (Tables)	3 Months Ended
	Mar. 31, 2021
Business Combinations [Abstract]
Carrying Value of Assets and Liabilities Held for Sale	The following table summarizes the carrying value of the assets and liabilities held for sale at March 31, 2021 and December 31, 2020: (in thousands) March 31, 2021 December 31, 2020 Accounts receivable – trade, net $ — $ 2,103 Accounts receivable – other — 86 Contracts in progress — 458 Inventories — 1,676 Other current assets — 405 Current assets held for sale — 4,728 Net property, plant and equipment 1,870 10,365 Intangible assets — 759 Right-of-use-asset — 32 Non-current assets held for sale 1,870 11,156 Total assets held for sale $ 1,870 $ 15,884 Accounts payable $ — $ 5,211 Accrued employee benefits — 178 Advance billings on contracts — 370 Accrued warranty expense — 466 Operating lease liabilities — 32 Other accrued liabilities — 2,048 Current liabilities held for sale — 8,305 Total liabilities held for sale $ — $ 8,305

BASIS OF PRESENTATION (Details)

BASIS OF PRESENTATION (Details) - USD ($) $ in Millions	1 Months Ended		3 Months Ended
	Mar. 31, 2021	Jan. 31, 2021	Mar. 31, 2021	Mar. 31, 2020
Accounting Policies [Abstract]
Deferred contribution payments	$ 20.9		$ 0.4
Company contributions	$ 45.6	$ 23.1	$ 24	$ 0.4

EARNINGS PER SHARE - Computatio

EARNINGS PER SHARE - Computation of Basic and Diluted Earnings Per Share (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Earnings Per Share [Abstract]
Loss from continuing operations	$ (15,464)	$ (33,439)
Income from discontinued operations, net of tax	0	1,913
Net loss attributable to stockholders	$ (15,464)	$ (31,526)
Weighted average shares used to calculate diluted earnings (loss) per share (in shares)	71,396	46,403
Weighted average shares used to calculate basic earnings (loss) per share (in shares)	71,396	46,403
Basic and diluted (loss) earnings per share
Basic loss per share - continuing operations (in dollars per share)	$ (0.22)	$ (0.72)
Basic earnings per share - discontinued operations (in dollars per share)	0	0.04
Basic loss per share (in dollars per share)	(0.22)	(0.68)
Diluted loss per share - continuing operations (in dollars per share)	(0.22)	(0.72)
Diluted earnings per share - discontinued operations (in dollars per share)	0	0.04
Diluted loss per share (in dollars per share)	$ (0.22)	$ (0.68)

EARNINGS PER SHARE - Additional

EARNINGS PER SHARE - Additional Information (Details) - shares shares in Millions	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Earnings Per Share [Abstract]
Excluded shares from the WAS to calculated diluted EPS as company was in a net loss position (in shares)	1.6	0.5
Stock options from diluted share (in shares)	0.4	0.5

SEGMENT REPORTING - Narrative (

SEGMENT REPORTING - Narrative (Details)	3 Months Ended
	Mar. 31, 2021segment
Segment Reporting [Abstract]
Number of reportable segments	3

SEGMENT REPORTING - Schedule of

SEGMENT REPORTING - Schedule of Operating Results by Segment (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Segment Reporting Information [Line Items]
Revenues	$ 168,248	$ 148,554
Adjusted EBITDA	8,462	958
Research and development costs	(588)	(1,341)
Restructuring activities	(993)	(1,951)
Financial advisory services	(933)	(929)
Advisory fees for settlement costs and liquidity planning	(1,978)	(2,614)
Litigation legal costs	(380)	(696)
Stock compensation	(7,829)	(712)
Interest on letters of credit included in cost of operations	(286)	(152)
Loss from business held for sale	(483)	(788)
Depreciation & amortization	(4,058)	(4,208)
Gain (loss) from a non-strategic business	12	(121)
Gain on asset disposals, net	2,004	915
Operating loss	(6,462)	(10,298)
Interest expense, net	(14,114)	(22,051)
Gain on sale of business	358	0
Net pension benefit	9,098	7,536
Foreign exchange	(1,209)	(9,326)
Other – net	(278)	(206)
Total other expense	(6,145)	(24,047)
Loss before income tax (benefit) expense	(12,607)	(34,345)
Income tax (benefit) expense	2,836	(810)
Loss from continuing operations	(15,443)	(33,535)
Income from discontinued operations, net of tax	0	1,913
Net loss	(15,443)	(31,622)
Net (income) loss attributable to non-controlling interest	(21)	96
Net loss attributable to stockholders	(15,464)	(31,526)
Losses related to a non-strategic business, previously included in adjusted EBITDA		(100)
Interest on letters of credit included in cost of operations, previously included in adjusted EBITDA		(200)
Other
Segment Reporting Information [Line Items]
Revenues	(4)	(48)
Corporate
Segment Reporting Information [Line Items]
Adjusted EBITDA	(2,685)	(4,143)
Research and development costs
Segment Reporting Information [Line Items]
Research and development costs	(588)	(1,341)
B&W Renewable segment | Operating Segments
Segment Reporting Information [Line Items]
Revenues	28,811	35,999
Adjusted EBITDA	204	(1,434)
B&W Renewable segment | Operating Segments | B&W Renewable
Segment Reporting Information [Line Items]
Revenues	17,997	22,338
B&W Renewable segment | Operating Segments | Vølund
Segment Reporting Information [Line Items]
Revenues	10,814	13,661
B&W Environmental segment | Operating Segments
Segment Reporting Information [Line Items]
Revenues	31,160	25,920
Adjusted EBITDA	1,101	270
B&W Environmental segment | Operating Segments | B&W Environmental
Segment Reporting Information [Line Items]
Revenues	17,433	12,935
B&W Environmental segment | Operating Segments | SPIG
Segment Reporting Information [Line Items]
Revenues	11,184	11,337
B&W Environmental segment | Operating Segments | GMAB
Segment Reporting Information [Line Items]
Revenues	2,543	1,648
B&W Thermal segment | Operating Segments
Segment Reporting Information [Line Items]
Revenues	108,281	86,683
Adjusted EBITDA	10,430	7,606
B&W Thermal segment | Operating Segments | B&W Thermal
Segment Reporting Information [Line Items]
Revenues	$ 108,281	$ 86,683

REVENUE RECOGNITION AND CONTR_3

REVENUE RECOGNITION AND CONTRACTS - Revenue Recognition (Details)	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Transferred at Point in Time
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Percent of revenue	27.00%	31.00%
Transferred over Time
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Percent of revenue	73.00%	69.00%

REVENUE RECOGNITION AND CONTR_4

REVENUE RECOGNITION AND CONTRACTS - Contract Assets and Liabilities (Details) - USD ($) $ in Thousands	3 Months Ended	12 Months Ended
	Mar. 31, 2021	Dec. 31, 2020
Contract assets - included in contracts in progress:
Costs incurred less costs of revenue recognized	$ 27,096	$ 25,888
Revenues recognized less billings to customers	39,137	33,420
Contracts in progress	66,233	59,308
Contract liabilities - included in advance billings on contracts:
Billings to customers less revenues recognized	80,328	61,884
Costs of revenue recognized less cost incurred	1,425	2,118
Advance billings on contracts	81,753	64,002
Net contract balance	(15,520)	(4,694)
Accrued contract losses	453	$ 582
Accounting Standards Update 2014-09 | Topic 606
Contract assets - included in contracts in progress:
Costs incurred less costs of revenue recognized	$ 1,208
Costs incurred less costs of revenue recognized, % Change	5.00%
Revenues recognized less billings to customers	$ 5,717
Revenues recognized less billings to customers, % Change	17.00%
Contracts in progress	$ 6,925
Contracts in progress, % Change	12.00%
Contract liabilities - included in advance billings on contracts:
Billings to customers less revenues recognized	$ 18,444
Billings to customers less revenues recognized, % Change	30.00%
Costs of revenue recognized less cost incurred	$ (693)
Costs of revenue recognized less cost incurred, % Change	(33.00%)
Advance billings on contracts	$ 17,751
Advance billings on contracts, % Change	28.00%
Net contract balance	$ (10,826)
Net contract balance, % Change	231.00%
Accrued contract losses	$ (129)
Accrued contract losses, % Change	(22.00%)

REVENUE RECOGNITION AND CONTR_5

REVENUE RECOGNITION AND CONTRACTS - Backlog (Details) $ in Millions	Mar. 31, 2021USD ($)
Revenue from Contract with Customer [Abstract]
Remaining performance obligation	$ 535
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2021-04-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Remaining performance obligations (as a percent)	51.00%
Expected timing of satisfaction, period	9 months
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2022-01-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Remaining performance obligations (as a percent)	18.70%
Expected timing of satisfaction, period	1 year
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2023-01-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Remaining performance obligations (as a percent)	30.30%
Expected timing of satisfaction, period

REVENUE RECOGNITION AND CONTR_6

REVENUE RECOGNITION AND CONTRACTS - Changes in Contract Estimates (Details) - Transferred over Time - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Disaggregation of Revenue [Line Items]
Increases in gross profit for changes in estimates for over time contracts	$ 3,025	$ 8,182
Decreases in gross profit for changes in estimates for over time contracts	(1,358)	(4,845)
Net changes in gross profit for changes in estimates for over time contracts	$ 1,667	$ 3,337

REVENUE RECOGNITION AND CONTR_7

REVENUE RECOGNITION AND CONTRACTS - B&W Renewable EPC Loss Contracts (Details) - B&W Renewable segment	1 Months Ended	3 Months Ended
	Oct. 31, 2020USD ($)contract	Mar. 31, 2021USD ($)contract	Mar. 31, 2020USD ($)contract	Oct. 23, 2020contract	Dec. 31, 2017contract
Disaggregation of Revenue [Line Items]
Number of contracts in a loss position | contract				6	6
Renewable loss contracts, net gain (loss) recognized on changes in estimated revenues and costs		$ 100,000	$ 100,000
Number of contracts with an increase in estimates of anticipated liquidated damages | contract		6	6
Percentage of completion on European renewable energy project		100.00%
Estimate of anticipated liquidated damages		$ 92,500,000	$ 86,500,000
Number of loss contracts settled | contract	5
Other renewable energy projects
Disaggregation of Revenue [Line Items]
Percentage of completion on European renewable energy project		99.00%
Change in construction cost estimates		$ 0
Fifth European Renewable project
Disaggregation of Revenue [Line Items]
Structural steel beam costs		$ 36,000,000
Five of Six European Renewable Project
Disaggregation of Revenue [Line Items]
Proceeds from insurance settlement	$ 26,000,000

REVENUE RECOGNITION AND CONTR_8

REVENUE RECOGNITION AND CONTRACTS - B&W Environmental Loss Contracts (Details) - B&W Environmental segment	3 Months Ended
	Mar. 31, 2021USD ($)contract	Mar. 31, 2020USD ($)
Disaggregation of Revenue [Line Items]
Number of contracts in a loss position | contract	2
Renewable loss contracts, net gain (loss) recognized on changes in estimated revenues and costs | $	$ 0	$ 0
First SPIG Contract
Disaggregation of Revenue [Line Items]
Percent complete	100.00%
Second SPIG Contract
Disaggregation of Revenue [Line Items]
Percent complete	99.00%

INVENTORIES (Details)

INVENTORIES (Details) - USD ($) $ in Thousands	Mar. 31, 2021	Dec. 31, 2020
Inventory Disclosure [Abstract]
Raw materials and supplies	$ 46,851	$ 46,659
Work in progress	8,460	8,195
Finished goods	12,553	12,307
Total inventories	$ 67,864	$ 67,161

PROPERTY, PLANT & EQUIPMENT, _3

PROPERTY, PLANT & EQUIPMENT, & FINANCE LEASE (Details) - USD ($) $ in Thousands	Mar. 31, 2021	Dec. 31, 2020
Property, Plant and Equipment [Line Items]
Property, plant and equipment - gross	$ 191,222	$ 192,526
Less accumulated depreciation	137,025	135,925
Net property, plant and equipment	54,197	56,601
Finance lease	34,254	30,551
Less finance lease accumulated amortization	2,603	2,074
Net property, plant and equipment, and finance lease	85,848	85,078
Land
Property, Plant and Equipment [Line Items]
Property, plant and equipment - gross	1,533	1,584
Buildings
Property, Plant and Equipment [Line Items]
Property, plant and equipment - gross	33,902	34,207
Machinery and equipment
Property, Plant and Equipment [Line Items]
Property, plant and equipment - gross	150,605	151,399
Property under construction
Property, Plant and Equipment [Line Items]
Property, plant and equipment - gross	$ 5,182	$ 5,336

GOODWILL - Schedule of Goodwill

GOODWILL - Schedule of Goodwill (Details)	3 Months Ended
	Mar. 31, 2021USD ($)
Goodwill [Roll Forward]
Beginning balance	$ 47,363,000
Currency translation adjustments	(9,000)
Ending balance	47,354,000
Goodwill and other intangible asset impairment	0
B&W Renewable
Goodwill [Roll Forward]
Beginning balance	10,211,000
Currency translation adjustments	(1,000)
Ending balance	10,210,000
B&W Environmental
Goodwill [Roll Forward]
Beginning balance	5,673,000
Currency translation adjustments	(1,000)
Ending balance	5,672,000
B&W Thermal
Goodwill [Roll Forward]
Beginning balance	31,479,000
Currency translation adjustments	(7,000)
Ending balance	$ 31,472,000

INTANGIBLE ASSETS - Intangible

INTANGIBLE ASSETS - Intangible Assets (Details) - USD ($) $ in Thousands	Mar. 31, 2021	Dec. 31, 2020	Mar. 31, 2020	Dec. 31, 2019
Definite-lived intangible assets
Gross value of definite-lived intangible assets	$ 64,724	$ 65,567
Accumulated amortization	(43,820)	(42,964)
Net definite-lived intangible assets	20,904	22,603
Indefinite-lived intangible assets
Total intangible assets, net	22,209	23,908	$ 24,332	$ 25,300
Trademarks and trade names
Indefinite-lived intangible assets
Trademarks and trade names	1,305	1,305
Customer relationships
Definite-lived intangible assets
Gross value of definite-lived intangible assets	24,102	24,862
Accumulated amortization	(19,762)	(19,537)
Unpatented technology
Definite-lived intangible assets
Gross value of definite-lived intangible assets	15,321	15,713
Accumulated amortization	(7,149)	(6,751)
Patented technology
Definite-lived intangible assets
Gross value of definite-lived intangible assets	3,114	2,642
Accumulated amortization	(2,616)	(2,593)
Tradename
Definite-lived intangible assets
Gross value of definite-lived intangible assets	12,769	13,088
Accumulated amortization	(4,978)	(4,831)
All other
Definite-lived intangible assets
Gross value of definite-lived intangible assets	9,418	9,262
Accumulated amortization	$ (9,315)	$ (9,252)

INTANGIBLE ASSETS - Summary of

INTANGIBLE ASSETS - Summary of Changes in Carrying Amount of Intangible Assets (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Intangible Assets [Roll Forward]
Balance at beginning of period	$ 23,908	$ 25,300
Amortization expense	(856)	(895)
Currency translation adjustments	(843)	(73)
Balance at end of the period	$ 22,209	$ 24,332

INTANGIBLE ASSETS - Estimated F

INTANGIBLE ASSETS - Estimated Future Intangible Asset Amortization (Details) $ in Thousands	Mar. 31, 2021USD ($)
Goodwill and Intangible Assets Disclosure [Abstract]
Year ending December 31, 2021	$ 2,470
Year ending December 31, 2022	3,321
Year ending December 31, 2023	3,319
Year ending December 31, 2024	3,247
Year ending December 31, 2025	2,549
Year ending December 31, 2026	1,292
Thereafter	$ 4,706

LEASES - Narrative (Details)

LEASES - Narrative (Details) - USD ($) $ in Thousands	Mar. 31, 2021	Dec. 31, 2020
Lessor, Lease, Description [Line Items]
Additional future minimum payments	$ 56,626
Lease liability	34,075
Finance lease assets	31,651	$ 28,477
Office Space Akron Ohio
Lessor, Lease, Description [Line Items]
Additional future minimum payments	$ 5,700
Finance lease, borrowing rate	7.00%
Lease liability	$ 3,700
Finance lease assets	$ 3,700

LEASES - Components of Lease Ex

LEASES - Components of Lease Expense (Details) - USD ($) $ in Thousands	3 Months Ended		12 Months Ended
	Mar. 31, 2021	Mar. 31, 2020	Dec. 31, 2020
Leases [Abstract]
Operating lease expense	$ 1,339	$ 1,507
Short-term lease expense	1,155	188
Variable lease expense	208	776
Total operating lease expense	2,702	2,471
Amortization of right-of-use assets	529	515
Interest on lease liabilities	616	615	$ 615
Total finance lease expense	1,145	1,130
Sublease income	(22)	(22)
Net lease cost	$ 3,825	$ 3,579

LEASES - Other Information Rela

LEASES - Other Information Related to Leases (Details) - USD ($) $ in Thousands	3 Months Ended		12 Months Ended
	Mar. 31, 2021	Mar. 31, 2020	Dec. 31, 2020
Cash paid for amounts included in the measurement of lease liabilities:
Operating cash flows from operating leases	$ 1,355		$ 1,400
Operating cash flows from finance leases	616	$ 615	615
Financing cash flows from finance leases	203		(586)
Right-of-use assets obtained in exchange for lease liabilities:
Operating leases	491		2,629
Finance leases	$ 3,702		$ 146
Weighted-average remaining lease term:
Operating leases (in years)	3 years		3 years 1 month 6 days
Finance leases (in years)	13 years 6 months		13 years 10 months 24 days
Weighted-average discount rate:
Operating leases	9.28%		9.26%
Finance leases	7.92%		8.00%

LEASES - Supplemental Balance S

LEASES - Supplemental Balance Sheet Information (Details) - USD ($) $ in Thousands	Mar. 31, 2021	Dec. 31, 2020
Assets:
Operating lease assets	$ 9,513	$ 10,814
Finance lease assets	31,651	28,477
Total non-current lease assets	41,164	39,291
Current
Operating lease liabilities	3,578	3,995
Finance lease liabilities	920	886
Non-current
Operating lease liabilities	6,137	7,031
Finance lease liabilities	33,155	29,690
Total lease liabilities	$ 43,790	$ 41,602

LEASES - Future Minimum Lease P

LEASES - Future Minimum Lease Payments Required (Details) $ in Thousands	Mar. 31, 2021USD ($)
Operating Leases
2021 (excluding the three months ended March 31, 2021)	$ 3,467
2022	3,439
2023	2,407
2024	1,326
2025	313
Thereafter	19
Total	10,971
Less imputed interest	(1,256)
Lease liability	9,715
Finance Leases
2021 (excluding the three months ended March 31, 2021)	2,629
2022	3,793
2023	3,879
2024	3,944
2025	3,969
Thereafter	38,412
Total	56,626
Less imputed interest	(22,551)
Lease liability	34,075
Total
2021 (excluding the three months ended March 31, 2021)	6,096
2022	7,232
2023	6,286
2024	5,270
2025	4,282
Thereafter	38,431
Total	67,597
Less imputed interest	(23,807)
Lease liability	$ 43,790

ACCRUED WARRANTY EXPENSE (Detai

ACCRUED WARRANTY EXPENSE (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Movement in Extended Product Warranty Accrual [Roll Forward]
Balance at beginning of period	$ 25,399	$ 33,376
Additions	1,475	1,350
Expirations and other changes	(1,318)	(517)
Payments	(5,943)	(3,119)
Translation and other	(76)	(137)
Balance at end of period	$ 19,537	$ 30,953

RESTRUCTURING ACTIVITIES - Summ

RESTRUCTURING ACTIVITIES - Summary of Restructuring Activity (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Restructuring Cost and Reserve [Line Items]
Total	$ 993	$ 1,951
Severance and related costs	500	1,101
Other	493	850
Cumulative costs to date		41,307
Severance and related costs
Restructuring Cost and Reserve [Line Items]
Cumulative costs to date		33,713
Other
Restructuring Cost and Reserve [Line Items]
Cumulative costs to date		7,594
Operating Segments | B&W Renewable segment
Restructuring Cost and Reserve [Line Items]
Total	509	801
Severance and related costs	453	658
Other	56	143
Operating Segments | B&W Environmental segment
Restructuring Cost and Reserve [Line Items]
Total	89	140
Severance and related costs	35	57
Other	54	83
Operating Segments | B&W Thermal segment
Restructuring Cost and Reserve [Line Items]
Total	348	941
Severance and related costs	12	386
Other	336	555
Corporate
Restructuring Cost and Reserve [Line Items]
Total	47	69
Severance and related costs	0	0
Other	$ 47	$ 69

RESTRUCTURING ACTIVITIES - Rest

RESTRUCTURING ACTIVITIES - Restructuring Liabilities (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Restructuring Reserve [Roll Forward]
Balance at beginning of period	$ 8,146	$ 5,358
Restructuring expense	993	1,951
Payments	(1,117)	(1,968)
Balance at end of period	$ 8,022	$ 5,341

PENSION PLANS AND OTHER POSTR_3

PENSION PLANS AND OTHER POSTRETIREMENT BENEFITS - Components of Net Periodic Benefit Cost (Detail) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Pension Benefits
Defined Benefit Plan Disclosure [Line Items]
Interest cost	$ 5,671	$ 8,261
Expected return on plan assets	(15,009)	(15,641)
Amortization of prior service cost (credit)	28	43
Benefit plans, net	(9,310)	(7,337)
Service cost included in COS	217	211
Net periodic benefit cost (benefit)	(9,093)	(7,126)
Other Benefits
Defined Benefit Plan Disclosure [Line Items]
Interest cost	39	72
Expected return on plan assets	0	0
Amortization of prior service cost (credit)	173	(271)
Benefit plans, net	212	(199)
Service cost included in COS	6	5
Net periodic benefit cost (benefit)	$ 218	$ (194)

PENSION PLANS AND OTHER POSTR_4

PENSION PLANS AND OTHER POSTRETIREMENT BENEFITS - Narrative (Details) - USD ($)	1 Months Ended		3 Months Ended
	Mar. 31, 2021	Jan. 31, 2021	Mar. 31, 2021	Mar. 31, 2020
Retirement Benefits [Abstract]
(Gains) losses on sale of business			$ 0	$ 0
Company contributions	$ 45,600,000	$ 23,100,000	24,000,000	$ 400,000
Deferred contribution payments	$ 20,900,000		$ 400,000

2021 SENIOR NOTES OFFERING - Na

2021 SENIOR NOTES OFFERING - Narrative (Details) - USD ($)	May 10, 2021	Feb. 21, 2021	Feb. 12, 2021	Mar. 31, 2021	Mar. 31, 2020	May 07, 2021	Feb. 11, 2021	Feb. 08, 2021
Debt Instrument [Line Items]
Issuance of senior notes				$ 125,000,000	$ 0
Subsequent Event | 7.75% Series A Cumulative Perpetual Preferred Stock
Debt Instrument [Line Items]
Liquidation preference (in dollars per share)						$ 25
Price per share (In dollars per share)						$ 25
Senior Notes
Debt Instrument [Line Items]
Redemption price, percentage		100.00%
Senior Notes | Subsequent Event
Debt Instrument [Line Items]
Issuance of senior notes	$ 11,000,000
Debt face amount	10,600,000
Net cash proceeds after commission and fees	$ 10,700,000
Senior Notes | February 28, 2023
Debt Instrument [Line Items]
Price per share (In dollars per share)			$ 25.75
Senior Notes | February 29, 2024
Debt Instrument [Line Items]
Price per share (In dollars per share)			25.50
Senior Notes | February 28, 2025
Debt Instrument [Line Items]
Price per share (In dollars per share)			$ 25.25
B. Riley Financial, Inc.
Debt Instrument [Line Items]
Fixed rate per annum			6.625%				12.00%
B. Riley Financial, Inc. | Senior Notes
Debt Instrument [Line Items]
Debt face amount								$ 5,000,000
8.125% Senior Notes Due 2026 | Senior Notes
Debt Instrument [Line Items]
Issuance of senior notes			$ 125,000,000
Fixed rate per annum			8.125%					8.125%
Proceeds from issuance of debt, net			$ 120,000,000
8.125% Senior Notes Due 2026 | B. Riley Financial, Inc. | Senior Notes
Debt Instrument [Line Items]
Debt face amount				$ 150,000,000

2021 SENIOR NOTES OFFERING - Co

2021 SENIOR NOTES OFFERING - Components of The Senior Notes (Details) - USD ($) $ in Thousands	Mar. 31, 2021	Dec. 31, 2020
Debt Instrument [Line Items]
Unamortized deferred financing costs	$ 4,491
Net debt balance	155,509	$ 183,330
Senior Notes | 8.125% Senior Notes Due 2026
Debt Instrument [Line Items]
Long-term debt, gross	$ 160,000

2021 COMMON STOCK OFFERING (Det

2021 COMMON STOCK OFFERING (Details) - USD ($) $ in Thousands	Feb. 12, 2021	Mar. 31, 2021	Mar. 31, 2020
Equity [Abstract]
Common stock shares issued (in shares)	29,487,180
Issuance of common stock, net	$ 172,500	$ 161,513	$ 0
Proceeds from issuance of common stock, net	$ 163,000

LAST OUT TERM LOANS - Last Out

LAST OUT TERM LOANS - Last Out Term Loans by Tranche (Details) - USD ($) $ in Thousands	Jul. 23, 2019	Mar. 31, 2021	Mar. 31, 2021	Dec. 31, 2020
Debt Instrument [Line Items]
Proceeds				$ 171,660
Discount and fees				8,650
Paid-in-kind interest				3,020
Net debt balance		$ 155,509	$ 155,509	183,330
A-3 | Amended Credit Agreement
Debt Instrument [Line Items]
Fees associated with debt extinguishment	$ 39,700	40,000
Line of Credit | A-3
Debt Instrument [Line Items]
Proceeds			61,660	101,660
Discount and fees		8,650	8,650	8,650
Paid-in-kind interest		3,020	3,020	3,020
Net debt balance		$ 73,330	$ 73,330	113,330
Line of Credit | A-4
Debt Instrument [Line Items]
Proceeds				30,000
Discount and fees				0
Paid-in-kind interest				0
Net debt balance				30,000
Line of Credit | A-6
Debt Instrument [Line Items]
Proceeds				40,000
Discount and fees				0
Paid-in-kind interest				0
Net debt balance				$ 40,000

LAST OUT TERM LOANS - Narrative

LAST OUT TERM LOANS - Narrative (Details) - USD ($)

Mar. 04, 2021

Nov. 30, 2020

May 14, 2020

Jan. 31, 2020

Jul. 23, 2019

Mar. 31, 2021

Mar. 31, 2021

May 13, 2021

May 10, 2021

Feb. 12, 2021

Feb. 11, 2021

Feb. 08, 2021

Dec. 31, 2020

Debt Instrument [Line Items]

Senior notes

$ 155,509,000

$ 155,509,000

$ 0

Subsequent Event | Senior Notes

Debt Instrument [Line Items]

Debt face amount

$ 10,600,000

B. Riley Financial, Inc.

Debt Instrument [Line Items]

Fixed rate per annum

6.625%

12.00%

B. Riley Financial, Inc. | Senior Notes

Debt Instrument [Line Items]

Debt face amount

$ 5,000,000

A-3 | Amended Credit Agreement

Debt Instrument [Line Items]

Borrowings under last out term loans

141,400,000

Fees associated with debt extinguishment

$ 39,700,000

$ 40,000,000

A-3 | A And R Amendment No3

Debt Instrument [Line Items]

Fees associated with debt extinguishment

$ 40,000,000

A-3 | B. Riley Financial, Inc. | Amended Credit Agreement

Debt Instrument [Line Items]

Proceeds from related party

150,000,000

A-4 | B. Riley Financial, Inc. | Amended Credit Agreement

Debt Instrument [Line Items]

Proceeds from related party

$ 30,000,000

Borrowings under last out term loans

26,300,000

Borrowing fees

$ 3,700,000

A-4 | B. Riley Financial, Inc. | A And R Amendment No3

Debt Instrument [Line Items]

Repayments of debt

$ 30,000,000

A-5 | A&R Credit Agreement | Subsequent Event

Debt Instrument [Line Items]

Current borrowing capacity

$ 0

A-6 | B. Riley Financial, Inc. | Senior Notes

Debt Instrument [Line Items]

Debt face amount

$ 35,000,000

A-6 | B. Riley Financial, Inc. | A And R Amendment No3

Debt Instrument [Line Items]

Repayments of debt

$ 5,000,000

A-6 | B. Riley Financial, Inc. | A&R Credit Agreement

Debt Instrument [Line Items]

Proceeds from related party

$ 30,000,000

Borrowings under last out term loans

$ 10,000,000

A-7 | A&R Credit Agreement | Subsequent Event

Debt Instrument [Line Items]

Current borrowing capacity

$ 0

A-7 | B. Riley Financial, Inc. | A&R Credit Agreement

Debt Instrument [Line Items]

Proceeds from related party

$ 50,000,000

REVOLVING DEBT (Details)

REVOLVING DEBT (Details)	Feb. 16, 2021USD ($)	Feb. 12, 2021USD ($)	Mar. 31, 2021USD ($)	Mar. 31, 2020USD ($)	Mar. 04, 2021USD ($)	Feb. 11, 2021	Feb. 08, 2021USD ($)	Dec. 31, 2020USD ($)	Oct. 30, 2020
Debt Instrument [Line Items]
Letters of credit outstanding			$ 18,000,000
Issuance of senior notes			125,000,000	$ 0
Proceeds from insurance settlement applied as permanent reduction to credit facility		$ 93,800,000
Letters of credit not secured by the US Credit Facility			60,700,000					$ 88,500,000
Letters of credit subject to foreign currency revaluation			27,300,000
Guarantor obligations			266,400,000
Surety Bond
Debt Instrument [Line Items]
Letters of credit outstanding			34,700,000
B. Riley Financial, Inc.
Debt Instrument [Line Items]
Fixed rate per annum		6.625%				12.00%
B. Riley Financial, Inc. | Senior Notes
Debt Instrument [Line Items]
Debt face amount							$ 5,000,000
8.125% Senior Notes Due 2026 | Senior Notes
Debt Instrument [Line Items]
Fixed rate per annum		8.125%					8.125%
Issuance of senior notes		$ 125,000,000
8.125% Senior Notes Due 2026 | B. Riley Financial, Inc. | Senior Notes
Debt Instrument [Line Items]
Debt face amount			$ 150,000,000
Last Out Term Loan Tranche A | Senior Notes
Debt Instrument [Line Items]
Debt instrument, allowed prepayment, amount		$ 35,000,000					$ 35,000,000
Debt face amount							$ 35,000,000
Percentage of proceeds used to repay outstanding borrowings							75.00%
U.S. Revolving Credit Facility
Debt Instrument [Line Items]
Borrowing amount								$ 164,300,000
U.S. Revolving Credit Facility | Letter of Credit
Debt Instrument [Line Items]
Letters of credit outstanding					$ 130,000,000
A&R Credit Agreement
Debt Instrument [Line Items]
Percentage of proceeds used to repay outstanding borrowings									50.00%
Permanent reduction of revolving credit facility		75.00%
A&R Credit Agreement | Quarter Ending June 30, 2021
Debt Instrument [Line Items]
Minimum interest coverage ratio			0.80
Maximum senior leverage ratio			4.25
A&R Credit Agreement | Quarter Ending September 30, 2021
Debt Instrument [Line Items]
Minimum interest coverage ratio			1
Maximum senior leverage ratio			3.75
A&R Credit Agreement | Quarter Ending December 31, 2021
Debt Instrument [Line Items]
Minimum interest coverage ratio			1.10
Maximum senior leverage ratio			3
A&R Credit Agreement | Quarter Ending March 31, 2022
Debt Instrument [Line Items]
Minimum interest coverage ratio			1.25
Maximum senior leverage ratio			2.25
Letter of Credit | Financial Standby Letter of Credit
Debt Instrument [Line Items]
Letters of credit outstanding			$ 22,000,000
Repayments of lines of credit	$ 167,100,000
Letter of Credit | Senior Secured Revolving Credit Facility
Debt Instrument [Line Items]
Letters of credit outstanding			82,100,000
Revolving Credit Facility
Debt Instrument [Line Items]
Remaining borrowing capacity			$ 25,900,000

INTEREST EXPENSE AND SUPPLEME_3

INTEREST EXPENSE AND SUPPLEMENTAL CASH FLOW INFORMATION (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Debt Instrument [Line Items]
Interest expense on borrowings	$ 6,662	$ 8,087
Amortization of deferred origination fees, net	5,868	12,843
Other interest expense	1,693	1,161
Total interest expense	14,223	22,091
Income tax payments, net	1,499	793
Total cash paid for interest	9,539	8,188
Senior Notes
Debt Instrument [Line Items]
Interest expense on borrowings	1,733	0
Amortization of deferred origination fees, net	1,468	0
Last Out Term Loans - cash interest
Debt Instrument [Line Items]
Interest expense on borrowings	3,513	4,048
Amortization of deferred origination fees, net	0	2,150
Total cash paid for interest	3,560	4,038
U.S. Revolving Credit Facility
Debt Instrument [Line Items]
Interest expense on borrowings	1,416	4,039
Total cash paid for interest	5,979	4,150
U.S. Revolving Credit Facility - deferred financing fees and commitment fees
Debt Instrument [Line Items]
Amortization of deferred origination fees, net	4,400	9,035
U.S. Revolving Credit Facility - deferred ticking fee for Amendment 16
Debt Instrument [Line Items]
Amortization of deferred origination fees, net	$ 0	$ 1,658

INTEREST EXPENSE AND SUPPLEME_4

INTEREST EXPENSE AND SUPPLEMENTAL CASH FLOW INFORMATION - Cash, Cash Equivalents and Restricted Cash (Details) - USD ($) $ in Thousands	Mar. 31, 2021	Dec. 31, 2020	Mar. 31, 2020
Cash and Cash Equivalents [Line Items]
Cash and cash equivalents of continuing operations	$ 53,833	$ 57,338	$ 35,384
Restricted cash and cash equivalents	4,613	10,085	11,001
Total cash, cash equivalents and restricted cash shown in the Condensed Consolidated Statements of Cash Flows	58,446	67,423	46,385
Held by foreign entities
Cash and Cash Equivalents [Line Items]
Cash and cash equivalents of continuing operations	25,169	38,726	27,937
Held by U.S. entities
Cash and Cash Equivalents [Line Items]
Cash and cash equivalents of continuing operations	28,664	18,612	7,447
Reinsurance reserve requirements
Cash and Cash Equivalents [Line Items]
Restricted cash and cash equivalents	2,053	4,551	5,779
Restricted foreign accounts
Cash and Cash Equivalents [Line Items]
Restricted cash and cash equivalents	0	2,869	3,107
Bank guarantee collateral
Cash and Cash Equivalents [Line Items]
Restricted cash and cash equivalents	$ 2,560	$ 2,665	$ 2,115

PROVISION FOR INCOME TAXES - Na

PROVISION FOR INCOME TAXES - Narrative (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Income Tax Contingency [Line Items]
Income tax expense (benefit)	$ 2,836	$ (810)
Effective tax rate	(22.50%)	2.40%
Favorable (unfavorable) discrete items	$ 2,500	$ 500
Minimum | Foreign Tax Authority
Income Tax Contingency [Line Items]
Effective tax rate	19.00%
Maximum | Foreign Tax Authority
Income Tax Contingency [Line Items]
Effective tax rate	30.00%

CONTINGENCIES (Details)

CONTINGENCIES (Details) - USD ($) $ in Millions	Jan. 11, 2021	Dec. 14, 2020	Dec. 27, 2019
Loss Contingencies [Line Items]
Loss contingency, damages sought, contractual cap		$ 11.7
Pending Litigation
Loss Contingencies [Line Items]
Alleged damages	$ 2.9		$ 58.9

COMPREHENSIVE INCOME - Accumula

COMPREHENSIVE INCOME - Accumulated Other Comprehensive Income (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward]
Beginning balance	$ (338,262)	$ (294,939)
Other comprehensive income (loss) before reclassifications	(70)	2,380
Reclassified from AOCI to net income (loss)	(4,314)	(246)
Other comprehensive (loss) income	(4,384)	2,134
Ending balance	(195,444)	(323,650)
Accumulated Other Comprehensive Loss
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward]
Beginning balance	(52,390)	1,926
Ending balance	(56,774)	4,060
Currency translation gain (loss)
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward]
Beginning balance	(47,575)	5,743
Other comprehensive income (loss) before reclassifications	(70)	2,380
Reclassified from AOCI to net income (loss)	(4,512)	0
Other comprehensive (loss) income	(4,582)	2,380
Ending balance	(52,157)	8,123
Net unrecognized loss related to benefit plans (net of tax)
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward]
Beginning balance	(4,815)	(3,817)
Other comprehensive income (loss) before reclassifications	0	0
Reclassified from AOCI to net income (loss)	198	(246)
Other comprehensive (loss) income	198	(246)
Ending balance	$ (4,617)	$ (4,063)

COMPREHENSIVE INCOME - Reclassi

COMPREHENSIVE INCOME - Reclassification out of Accumulated other Comprehensive Income (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Gain on sale of business	$ 358	$ 0
Benefit plans, net	9,098	7,536
Net income	(15,443)	(33,535)
Reclassification out of Accumulated Other Comprehensive Income | Amortization of prior service cost on benefit obligations
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Gain on sale of business	4,512	0
Benefit plans, net	(198)	246
Net income	$ 4,314	$ 246

FAIR VALUE MEASUREMENTS - Summa

FAIR VALUE MEASUREMENTS - Summary of Available-for-Sale Securities Measured at Fair Value (Details) - USD ($) $ in Thousands	Mar. 31, 2021	Dec. 31, 2020
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total fair value of available-for-sale securities	$ 13,206	$ 15,308
Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total fair value of available-for-sale securities	12,561	14,672
Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total fair value of available-for-sale securities	645	636
Corporate notes and bonds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total fair value of available-for-sale securities	7,804	6,139
Corporate notes and bonds | Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total fair value of available-for-sale securities	7,804	6,139
Corporate notes and bonds | Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total fair value of available-for-sale securities	0	0
Mutual funds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total fair value of available-for-sale securities	645	636
Mutual funds | Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total fair value of available-for-sale securities	0	0
Mutual funds | Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total fair value of available-for-sale securities	645	636
Corporate Stocks
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total fair value of available-for-sale securities		4,168
Corporate Stocks | Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total fair value of available-for-sale securities		4,168
Corporate Stocks | Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total fair value of available-for-sale securities		0
United States Government and agency securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total fair value of available-for-sale securities	4,757	4,365
United States Government and agency securities | Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total fair value of available-for-sale securities	4,757	4,365
United States Government and agency securities | Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total fair value of available-for-sale securities	$ 0	$ 0

FAIR VALUE MEASUREMENTS - Narra

FAIR VALUE MEASUREMENTS - Narrative (Details) - USD ($) $ in Thousands	Mar. 31, 2021	Feb. 12, 2021	Feb. 08, 2021
8.125% Senior Notes Due 2026 | Senior Notes
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fixed rate per annum		8.125%	8.125%
Principal	$ 160,000
Minimum
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available for sale securities contractual maturities	0 years
Maximum
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available for sale securities contractual maturities	5 years

FAIR VALUE MEASUREMENTS - Senio

FAIR VALUE MEASUREMENTS - Senior Notes (Details) - 8.125% Senior Notes Due 2026 - Senior Notes $ in Thousands	Mar. 31, 2021USD ($)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Carrying Value	$ 160,000
Estimated Fair Value	$ 169,536

RELATED PARTY TRANSACTIONS (Det

RELATED PARTY TRANSACTIONS (Details) - USD ($)	May 07, 2021	Mar. 26, 2021	Feb. 12, 2021	Nov. 13, 2020	Nov. 19, 2018	Jan. 31, 2021	Mar. 31, 2021	Mar. 31, 2020	May 10, 2021	Feb. 11, 2021	Feb. 08, 2021
Related Party Transaction [Line Items]
Payment of debt issuance costs							$ 7,727,000	$ 5,749,000
Common stock shares issued (in shares)			29,487,180
Senior Notes | Subsequent Event
Related Party Transaction [Line Items]
Debt face amount									$ 10,600,000
8.125% Senior Notes Due 2026 | Senior Notes
Related Party Transaction [Line Items]
Fixed rate per annum			8.125%								8.125%
Last Out Term Loan Tranche A | Senior Notes
Related Party Transaction [Line Items]
Debt face amount											$ 35,000,000
Debt instrument, allowed prepayment, amount			$ 35,000,000								35,000,000
7.75% Series A Cumulative Perpetual Preferred Stock | Subsequent Event
Related Party Transaction [Line Items]
Preferred stock, dividend rate	7.75%
BPRI Executive Consulting, LLC | Financial advisory services
Related Party Transaction [Line Items]
Related party transaction, period with written notice to terminate agreement					30 days
Related party transaction monthly payments					$ 750,000
B. Riley Financial, Inc.
Related Party Transaction [Line Items]
Total fees							200,000	$ 4,200,000
Proceeds from sale of stock						$ 4,500,000
Fixed rate per annum			6.625%							12.00%
B. Riley Financial, Inc. | Senior Notes
Related Party Transaction [Line Items]
Debt face amount											$ 5,000,000
B. Riley Financial, Inc. | 8.125% Senior Notes Due 2026 | Senior Notes
Related Party Transaction [Line Items]
Debt face amount							$ 150,000,000
B. Riley Securities, Inc.
Related Party Transaction [Line Items]
Payments of stock issuance costs			$ 9,500,000
B. Riley Securities, Inc. | Senior Notes
Related Party Transaction [Line Items]
Payment of debt issuance costs			$ 5,200,000
Eos Energy Storage LLC | Common Class A
Related Party Transaction [Line Items]
Purchase of common stock (in shares)				200,000
Payments to acquire stock				$ 2,000,000
Babcock & Wilcox Enterprises, Inc. | B. Riley Capital Management, LLC
Related Party Transaction [Line Items]
Ownership percent of common stock							33.20%
Babcock & Wilcox Enterprises, Inc. | Vintage Capital Management, LLC
Related Party Transaction [Line Items]
Ownership percent of common stock							0.00%
Common stock shares issued (in shares)		10,720,785

ASSETS HELD FOR SALE, DIVESTI_3

ASSETS HELD FOR SALE, DIVESTITURES AND DISCONTINUED OPERATIONS - Narrative (Details) - USD ($) $ in Thousands	Mar. 15, 2021	Mar. 08, 2021	Apr. 06, 2020	Mar. 17, 2020	Mar. 31, 2021	Mar. 31, 2020	Mar. 05, 2021
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Proceeds from sale of certain fixed assets, gross	$ 4,000
Proceeds from sale of certain fixed assets, net	3,300
Gain on sale of fixed assets	$ 1,900				$ 358	$ 0
Proceeds from sale of business and assets, net					3,297	0
Gain on sale of business					358	$ 0
Amount received after remaining escrow is settled			$ 3,500	$ 4,500
BPE Clyde Pte Ltd | Disposal Group, Disposed of by Sale
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Consideration from divestitures							$ 2,800
Proceeds from sale of business and assets, net		$ 2,000
Favorable contract asset recognized					800
Gain on sale of business					400
Gain on sale of business, CTA					$ 4,500

ASSETS HELD FOR SALE, DIVESTI_4

ASSETS HELD FOR SALE, DIVESTITURES AND DISCONTINUED OPERATIONS - Carrying Value of Assets and Liabilities Held for Sale (Details) - Discontinued Operations, Held-for-sale - USD ($) $ in Thousands	Mar. 31, 2021	Dec. 31, 2020
Schedule of Equity Method Investments [Line Items]
Accounts receivable – trade, net	$ 0	$ 2,103
Accounts receivable – other	0	86
Contracts in progress	0	458
Inventories	0	1,676
Other current assets	0	405
Current assets held for sale	0	4,728
Net property, plant and equipment	1,870	10,365
Intangible assets	0	759
Right-of-use-asset	0	32
Non-current assets held for sale	1,870	11,156
Total assets held for sale	1,870	15,884
Accounts payable	0	5,211
Accrued employee benefits	0	178
Advance billings on contracts	0	370
Accrued warranty expense	0	466
Operating lease liabilities	0	32
Other accrued liabilities	0	2,048
Current liabilities held for sale	0	8,305
Total liabilities held for sale	$ 0	$ 8,305

SUBSEQUENT EVENTS (Details)

SUBSEQUENT EVENTS (Details) - Subsequent Event - 7.75% Series A Cumulative Perpetual Preferred Stock	May 07, 2021USD ($)$ / sharesshares
Subsequent Event [Line Items]
Preferred stock, dividend rate	7.75%
Sale of stock, number of shares issued (in shares) | shares	4,000,000
Price per share (In dollars per share)	$ 25
Sale of stock, consideration received | $	$ 100,000,000
Preferred stock, par value (in dollars per share)	$ 0.01
Liquidation preference (in dollars per share)	$ 25
Net proceeds from issuance of preferred stock | $	$ 95,700,000
Preferred stock, equivalent dividend per year (in dollars per share)	$ 1.9375
Over-Allotment Option
Subsequent Event [Line Items]
Sale of stock, number of shares issued (in shares) | shares	600,000