Note 17 - Business Segments (Detail) - Segments' Asset (USD $)
3 Months Ended 12 Months Ended
Nov. 30, 2011
Aug. 31, 2011
Assets    
Segments $ 5,241,450,000 $ 5,487,034,000
Power [Member]
   
Assets    
Segments 2,061,400,000 2,129,000,000
Plant Services [Member]
   
Assets    
Segments 293,400,000 270,200,000
E&I [Member]
   
Assets    
Segments 1,056,000,000 1,060,900,000
E&C [Member]
   
Assets    
Segments 412,600,000 482,900,000
F&M [Member]
   
Assets    
Segments 686,400,000 710,000,000
Income taxes not allocated to segments 0 0
Westinghouse [Member]
   
Assets    
Segments 1,236,500,000 1,266,400,000
Corporate [Member]
   
Assets    
Segments 441,500,000 404,300,000
Total Segments [Member]
   
Assets    
Segments 6,187,800,000 6,323,700,000
Corporate Elimination [Member]
   
Assets    
Elimination of investment in consolidated subsidiaries (468,400,000) (368,300,000)
Business Intersegment, Eliminations [Member]
   
Assets    
Elimination of intercompany receivables (477,900,000) (468,400,000)
Total [Member]
   
Assets    
Segments $ 5,241,500,000 $ 5,487,000,000