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Stock-Based Compensation - Shares Issued in Connection with Stock Compensation Awards (Detail) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Share-based Payment Arrangement [Abstract]
New shares issued from available authorized shares	0	0
Shares issued from available treasury stock	513,824	66,215
Total	513,824	66,215
Proceeds from stock option exercises	$ 29,397	$ 1,463

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Treasury Shares Issued Related To Stock Option Exercises

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Amount of cash inflow from exercise of option under share-based payment arrangement.

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Number of shares issued under share-based payment arrangement.

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Number of shares issued during the period as a result of an employee stock purchase plan.

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