Stock Plans - Summary of Stock Option Activity (Detail) - $ / shares	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Shares
Beginning balance, outstanding (in shares)	161,701	283,998	559,656
Exercised (in shares)	(103,545)	(122,087)	(274,704)
Forfeited (in shares)		(210)	(954)
Ending balance, outstanding (in shares)	58,156	161,701	283,998
Weighted Average Exercise Price
Beginning, weighted average exercise price (in dollars per share)	$ 45.47	$ 46.23	$ 45.78
Exercised (in dollars per share)	44.91	47.25	45.31
Forfeited (in dollars per share)		43.75	42.00
Ending, weighted average exercise price (in dollars per share)	$ 46.48	$ 45.47	$ 46.23
Exercisable at year-end (in shares)	58,156	161,347	281,593