Quarterly report pursuant to Section 13 or 15(d)

COMMON STOCK AND CHANGES IN CAPITALIZATION (Details)

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COMMON STOCK AND CHANGES IN CAPITALIZATION (Details) - USD ($)
 3 Months Ended
Mar. 31, 2019
Mar. 31, 2018
Jan. 31, 2019
May 31, 2018
Jan. 31, 2018
Class of Stock [Line Items]          
Stock repurchase program, amount authorized to acquire     $ 400,000,000.0   $ 100,000,000
Stock repurchase program, period in force 24 months        
Amount of shares repurchased $ 28,200,000        
Restricted Stock          
Class of Stock [Line Items]          
Shares repurchased to satisfy tax withholding requirements $ 100,000        
Common Stock          
Class of Stock [Line Items]          
Shares repurchased (in shares) 3,618,634 9,692,356      
Minimum          
Class of Stock [Line Items]          
Stock repurchase program, amount authorized to acquire       $ 100,000,000  
Maximum          
Class of Stock [Line Items]          
Stock repurchase program, amount authorized to acquire       $ 200,000,000