Accounting for Stock Based Compensation - Summarizes RSU Activity (Detail) - $ / shares	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Outstanding at beginning of period, Shares	13,600	11,376	34,906
Granted, Shares	17,923	13,600	13,742
Vested, Shares	(11,900)	(11,376)	(37,272)
Forfeited, Shares	(1,700)
Outstanding at end of period, Shares	17,923	13,600	11,376
Outstanding at beginning of period, Weighted-Average Grant Date Fair Value	$ 73.54	$ 70.33	$ 39.82
Granted, Weighted-Average Grant Date Fair Value	56.96	73.54	70.18
Vested, Weighted-Average Grant Date Fair Value	73.54	70.33	41.7
Forfeited, Weighted-Average Grant Date Fair Value	73.54
Outstanding at end of period, Weighted-Average Grant Date Fair Value	$ 56.96	$ 73.54	$ 70.33
RSU | Time Vesting Shares [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Outstanding at beginning of period, Shares	201,578	193,626	208,905
Granted, Shares	136,964	117,507	93,539
Vested, Shares	(82,695)	(95,692)	(88,296)
Forfeited, Shares	(23,986)	(13,863)	(20,522)
Outstanding at end of period, Shares	231,861	201,578	193,626
Outstanding at beginning of period, Weighted-Average Grant Date Fair Value	$ 64.27	$ 56.02	$ 37.26
Granted, Weighted-Average Grant Date Fair Value	58.68	66.86	79.79
Vested, Weighted-Average Grant Date Fair Value	59.43	49.85	38.49
Forfeited, Weighted-Average Grant Date Fair Value	59.47	70.52	48.76
Outstanding at end of period, Weighted-Average Grant Date Fair Value	$ 63.19	$ 64.27	$ 56.02