Stock-Based Compensation - Shares Issued in Connection with Stock Compensation Awards (Detail) (USD $) In Thousands, except Share data, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
New shares issued from available authorized shares	0	0	0	153,275
Issued from available treasury stock	106,900	587,650	491,675	1,096,599
Total	106,900	587,650	491,675	1,249,874
Proceeds from stock option exercises	$ 5,464	$ 30,837	$ 25,573	$ 65,026