GOODWILL - Carrying Amount of Goodwill (Details) - USD ($) $ in Thousands	3 Months Ended
Mar. 31, 2023	Dec. 31, 2022
Goodwill [Line Items]
Goodwill		$ 288,660
Accumulated impairment losses		(131,667)
Goodwill [Roll Forward]
Beginning balance	$ 156,993
Currency translation adjustments	266
Ending balance	157,259
B&W Renewable segment
Goodwill [Line Items]
Goodwill		139,248
Accumulated impairment losses		(57,189)
Goodwill [Roll Forward]
Beginning balance	82,059
Currency translation adjustments	77
Ending balance	82,136
B&W Environmental
Goodwill [Line Items]
Goodwill		79,825
Accumulated impairment losses		(74,478)
Goodwill [Roll Forward]
Beginning balance	5,347
Currency translation adjustments	32
Ending balance	5,379
B&W Thermal segment
Goodwill [Line Items]
Goodwill		69,587
Accumulated impairment losses		$ 0
Goodwill [Roll Forward]
Beginning balance	69,587
Currency translation adjustments	157
Ending balance	$ 69,744

Amount after accumulated impairment loss of an asset representing future economic benefits arising from other assets acquired in a business combination that are not individually identified and separately recognized.

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Amount of foreign currency translation gain (loss) which increases (decreases) an asset representing future economic benefits from other assets acquired in a business combination that are not individually identified and separately recognized.

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