Quarterly report pursuant to Section 13 or 15(d)

FAIR VALUE OF FINANCIAL INSTRUMENTS (Details)

v2.4.0.6
FAIR VALUE OF FINANCIAL INSTRUMENTS (Details) (USD $)
Mar. 31, 2013
Dec. 31, 2012
Short-term debt    
Outstanding borrowings $ 0 $ 0
Revolving Credit Agreement
   
Short-term debt    
Line of credit maximum borrowing capacity 175,000,000  
Letter of credit subfacility
   
Short-term debt    
Line of credit maximum borrowing capacity 75,000,000  
Swingline subfacility
   
Short-term debt    
Line of credit maximum borrowing capacity $ 10,000,000