Note 16 - Accounting for Claims, Unapproved Change Orders and Incentives on Long-Term Construction Contracts (Detail) - Significant Unapproved Change Orders And Claims (USD $)
In Millions, unless otherwise specified
3 Months Ended
Nov. 30, 2012
Aug. 31, 2012
Nov. 30, 2011
Aug. 31, 2011
Nov. 30, 2012
Unapproved Change Orders [Member]
Nov. 30, 2011
Unapproved Change Orders [Member]
Amounts included in project estimates-at-completion at September 1 $ 383.5 $ 381.4 $ 449.2 $ 448.3    
Changes in estimates-at-completion         3.1 9.6
Approved by clients         (1.0) (8.7)
Amounts included in project estimates-at-completion at November 30 for unapproved change orders and claims 383.5 381.4 449.2 448.3    
Amounts recorded in revenues (or reductions to contract costs) on a percentage-of-completion basis at November 30         $ 95.3 $ 116.6