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TREASURY STOCK - Narrative (Details) - USD ($)
9 Months Ended 12 Months Ended
Sep. 30, 2017
Sep. 30, 2016
Dec. 31, 2016
Oct. 25, 2016
Treasury Stock Transactions, Excluding Value of Shares Reissued [Abstract]        
Stock repurchase program, authorized amount (up to)       $ 150,000,000.0
Amount available for share repurchase under this latest authorization $ 150,000,000      
Treasury stock (in shares) 2,900,000   2,900,000 2,900,000
Treasury stock $ 121,800,000   $ 123,100,000  
Treasury stock, average cost per share (in dollars per share) $ 41.77   $ 41.78  
Stock repurchased during period (in shares) 0 0