Stock-Based Compensation - Shares Issued in Connection with Stock Compensation Awards (Detail) (USD $) In Thousands, except Share data, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2014	Jun. 30, 2013	Jun. 30, 2014	Jun. 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	54,950	266,799	384,775	508,949
Total	54,950	266,799	384,775	662,224
Proceeds from stock option exercises	$ 2,830	$ 13,743	$ 20,109	$ 34,189