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Preferred Stock
12 Months Ended
Dec. 31, 2011
Preferred Stock [Abstract]  
Preferred Stock
5.  Preferred Stock

SPS has authorized the issuance of preferred stock.
 
Preferred
       
Preferred
Shares
       
Shares
Authorized
 
Par Value
 
Outstanding
10,000,000
 
$
1.00
 
 None