Stock Options and Other Equity-Based Incentive Instruments - Restricted Stock Unit (RSU) Activity (Detail) - Restricted Stock Units (RSUs)	12 Months Ended
	Dec. 31, 2022 $ / shares shares
Service Condition Vesting RSUs
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number of Shares [Roll Forward]
Outstanding, beginning balance (in shares)	103,517
RSUs granted (in shares)	84,278
Additional market plus service condition RSUs vested (in shares)	0
RSUs added through dividend credits (in shares)	2,896
RSUs released through vesting (in shares)	(50,076)
RSUs forfeited/expired (in shares)	(1,421)
Outstanding, ending balance (in shares)	139,194
RSUs granted, weighted average fair value on date of grant (in USD per share) | $ / shares	$ 44.00
Market Plus Service Condition Vesting RSUs
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number of Shares [Roll Forward]
Outstanding, beginning balance (in shares)	99,763
RSUs granted (in shares)	37,877
Additional market plus service condition RSUs vested (in shares)	4,740
RSUs added through dividend credits (in shares)	0
RSUs released through vesting (in shares)	(26,338)
RSUs forfeited/expired (in shares)	(1,561)
Outstanding, ending balance (in shares)	114,481
RSUs granted, weighted average fair value on date of grant (in USD per share) | $ / shares	$ 40.74