Earnings Per Share - Computation of Basic and Diluted Earnings Per Share (Detail) (USD $) In Thousands, except Share data, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2014	Jun. 30, 2013	Jun. 30, 2014	Jun. 30, 2013
Earnings Per Share Basic And Diluted [Abstract]
Net income attributable to The Babcock & Wilcox Company	$ 26,437	$ 72,870	$ 71,481	$ 120,044
Weighted average common shares (basic)	109,766,237	111,898,819	110,102,826	112,998,066
Basic earnings per common share	$ 0.24	$ 0.65	$ 0.65	$ 1.06
Stock options, restricted stock and performance shares	350,393	763,744	398,511	701,793
Adjusted weighted average common shares	110,116,630	112,662,563	110,501,337	113,699,859
Diluted earnings per common share	$ 0.24	$ 0.65	$ 0.65	$ 1.06