Note 12 - Contingencies and Commitments (Detail) (USD $)
In Millions, unless otherwise specified
0 Months Ended 3 Months Ended 3 Months Ended 6 Months Ended 3 Months Ended 3 Months Ended 11 Months Ended 0 Months Ended
Nov. 19, 2011
Nov. 30, 2011
Aug. 31, 2011
May 17, 2010
Maximum [Member]
Nov. 30, 2011
Unpaid Contract [Member]
F&M [Member]
Nov. 30, 2011
EPC [Member]
Nov. 30, 2011
Performance Letters of Credit [Member]
Nov. 30, 2011
Xcel Energy [Member]
Nov. 30, 2011
F&M [Member]
Jun. 30, 2011
F&M [Member]
Nov. 30, 2011
Power [Member]
Jun. 24, 2011
Power [Member]
Mar. 07, 2011
Power [Member]
Jan. 14, 2011
Power [Member]
Nov. 30, 2011
Five Clients [Member]
Nov. 30, 2011
Single Client [Member]
Nov. 30, 2011
E&I [Member]
Aug. 31, 2011
E&I [Member]
Nov. 30, 2011
Additional Costs [Member]
F&M [Member]
Nov. 30, 2011
Total [Member]
F&M [Member]
Jul. 11, 2011
Minimum [Member]
Nov. 30, 2011
Minimum [Member]
Power [Member]
Loss Contingency, Loss in Period               $ 63.4                            
Loss Contingency, Settlement Agreement, Consideration               $40                            
Gain Contingency, Unrecorded Amount       48.2 3.8 32.0         165.0 233.0 200.0 143.0           8.3   52.0
Line of Credit Facility, Increase, Additional Borrowings           19.0                                
Gain Contingency, Description           $19.0                         $4.5      
Loss Contingency, Damages Sought, Value 32.6               85.3 48.9                     38.4  
Supply Commitment, Remaining Minimum Amount Committed                 28.1                          
Loss Contingency, Actions Taken by Plaintiff                   $107.0                        
Litigation Settlement, Gross   16.8                                        
Increase (Decrease) in Accounts Receivable                     68.0                      
Letters of Credit Outstanding, Amount   431.8 456.1       181.2                              
Liabilities for Guarantees on Long-Duration Contracts, Other Liability Adjustments             282.9                              
Concentration Risk, Credit Risk                             $223.3              
Fair Value, Concentration of Risk, Commitments                               60.0            
Site Contingency, Accrual, Undiscounted Amount                                 $ 1.8 $ 1.9