Stock-Based Compensation - Shares Issued in Connection with Stock Compensation Awards (Detail) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Share-based Payment Arrangement [Abstract]
New shares issued from available authorized shares	0	0	0	0
Shares issued from available treasury stock	21,968	53,425	650,044	196,948
Total	21,968	53,425	650,044	196,948
Proceeds from stock option exercises	$ 1,128	$ 2,698	$ 37,810	$ 7,544