XML 80 R62.htm IDEA: XBRL DOCUMENT v3.7.0.1
Shares Repurchased - Additional Information (Detail) - Three-Year Share Repurchase Program [Member] - USD ($)
3 Months Ended 6 Months Ended
Apr. 27, 2016
Jun. 30, 2017
Jun. 30, 2016
Jun. 30, 2017
Jun. 30, 2016
Oct. 29, 2014
Class of Stock [Line Items]            
Common stock purchase authorized amount           $ 100,000,000
Share repurchase program, increase in authorized amount $ 60,000,000          
Share repurchase program, extended term date Apr. 27, 2019          
Repurchased common stock, shares   7,967 8,018 354,496 3,415,323  
Repurchased common stock, value   $ 65,000 $ 99,000 $ 3,693,000 $ 35,654,000  
Dollar amount remaining available for future share repurchases   $ 92,811,000   $ 92,811,000