Selected Financial Information Regarding Results of Operations of Former B&W Business (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended									12 Months Ended
	Mar. 31, 2012	Dec. 31, 2011		Sep. 30, 2011		Jun. 30, 2011		Mar. 31, 2011		Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Loss on disposal of discontinued operations, before taxes										$ 257	$ (21,934)	$ (123,311)
Income (loss) from discontinued operations, net of tax	3,497	(19,271)	[1]	1,187	[1],[2]	3,610	[1],[3]	1,662	[1]	3,497	(12,812)	(34,900)
Babcock and Wilcox Company
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Revenues												1,524,424	[4]
Loss on disposal of discontinued operations, before taxes												(95,621)	[4]
Income before provision for income taxes												105,796	[4]
Discontinued Operation, Income (Loss) from Discontinued Operation, before Income Tax												10,175	[4]
Provision for income taxes												(22,755)	[4]
Income (loss) from discontinued operations, net of tax												$ (12,580)	[4]

[1] See Note 2 in the notes to the consolidated financial statements for a discussion of discontinued operations and other items.

[2] Operating income for the September 30, 2011 quarter was influenced by the $75.4 million decline in the Middle East segment. The Middle East decline was primarily driven by reduced fabrication and marine activity levels, lower change orders, project close-outs and settlements on completed contracts. In addition, the September quarter was impacted by approximately $50.0 million of project charges recognized across segments.

[3] Operating income for the June 30, 2011 quarter was influenced by a $49.1 million decline in our Middle East segment as a result of reduced marine activity and the substantial completion of several higher margin projects in Saudi Arabia for which the marine activities were ongoing during the 2010 quarter but were complete prior to the 2011 quarter.

[4] Includes the B&W operations through July 30, 2010.