Commitments and Contingencies (Piedmont) (Narrative) (Details) (Piedmont, Florida [Member], USD $)
In Millions, unless otherwise specified
6 Months Ended 12 Months Ended
Mar. 31, 2015
Sep. 30, 2008
Loss Contingencies [Line Items]    
Accrual for environmental loss contingencies $ 18.4 $ 24.0
Years to complete environmental remediation (beginning in 2017)   15 years
Change in estimated exposure 0  
Total anticipated exposure at this site   24
Segment Discontinued Operations Member    
Loss Contingencies [Line Items]    
Pretax environmental expense   $ 24