Stock-Based Compensation - Shares Issued in Connection with Stock Compensation Awards (Detail) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
New shares issued from available authorized shares	0	0	0	0
Issued from available treasury stock	841,846	56,377	908,921	227,851
Total	841,846	56,377	908,921	227,851
Proceeds from stock option exercises	$ 44,287	$ 2,880	$ 47,873	$ 11,830