XML 65 R54.htm IDEA: XBRL DOCUMENT v3.10.0.1
STOCKHOLDERS' EQUITY - ADDITIONAL INFORMATION (Detail) - USD ($)
6 Months Ended
Jun. 30, 2017
Jun. 30, 2018
Dec. 31, 2017
Dec. 26, 2017
Oct. 22, 2014
Nov. 01, 2007
Class of Stock [Line Items]            
Stock repurchase program, additional authorized amount         $ 30,000,000 $ 50,000,000
Repurchased shares (in shares) 0          
Repurchased shares, value $ 0          
Stock repurchase program, remaining available repurchase amount   $ 33,400,000        
Common stock, par value (in dollars per share)   $ 0.001 $ 0.001 $ 0.001    
Rights, exercised (in shares) 0 0        
Series B Junior Participating Preferred Stock            
Class of Stock [Line Items]            
Right, exercise price (in dollars per share)       $ 30.00