Earnings Per Share - Computation of Basic and Diluted Earnings Per Share (Detail) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Amounts attributable to Babcock & Wilcox Enterprises, Inc.
Income from continuing operations	$ 6,169	$ 12,711	$ 21,542	$ 21,397
Income from discontinued operations, net of tax	0	(7,102)	2,803	237
Net income attributable to Babcock & Wilcox Enterprises, Inc.	$ 6,169	$ 5,609	$ 24,345	$ 21,634
Weighted average common shares used to calculate basic earnings per common share	53,758,000	53,553,000	53,569,000	54,552,000
Effect of dilutive securities:
Dilutive effect of stock options, restricted stock and performance shares	30,000	169,000	147,000	189,000
Weighted average common shares used to calculate diluted earnings per common share	53,787,000	53,722,000	53,716,000	54,741,000
Basic earnings per common share:
Continuing operations (usd per share)	$ 0.11	$ 0.24	$ 0.40	$ 0.39
Discontinued operations (usd per share)	0.00	(0.14)	0.05	0.01
Basic earnings per common share (usd per share)	0.11	0.10	0.45	0.40
Diluted earnings per common share:
Continuing operations (usd per share)	0.11	0.24	0.40	0.39
Discontinued operations (usd per share)	0.00	(0.14)	0.05	0.01
Diluted earnings per common share (usd per share)	$ 0.11	$ 0.10	$ 0.45	$ 0.40
Antidilutive shares related to stock options excluded from the diluted share (shares)			51,640	671,212