Quarterly report pursuant to Section 13 or 15(d)

Equity Offering (Details)

Equity Offering (Details) (Equity Program [Member], USD $)
In Millions, except Share data
3 Months Ended
Sep. 30, 2011
Sep. 14, 2011
Equity Program [Member]
Common stock value authorized under equity offering program   $ 125
Common stock shares issued under equity offering program 130,837  
Weighted average issue price of common stock $ 39.35  
Proceeds from issuance of common stock 4.8  
Offering related costs and commissions 0.1  
Expenses related to equity program 0.2  
Common stock, value reserved for future issuance $ 119.9