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Capital Management - Additional Information (Detail) - USD ($)	12 Months Ended			178 Months Ended
	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2024	Oct. 31, 2016
Equity [Abstract]
Share repurchase program, new limit amount					$ 25,000,000
Shares repurchased under the program	113,411	46,741	264,449
Shares repurchased under the program, value	$ 5,100,000	$ 2,200,000	$ 12,400,000
Shares repurchased, value	$ 42,052,000	$ 36,929,000		$ 42,052,000
Shares repurchased, average price	$ 45.17	$ 46.45	$ 46.84	$ 24.99
Shares repurchased	1,682,851	1,569,440		1,682,851
Quarterly dividend per share	$ 0.37	$ 0.34	0.31	$ 0.37
Extraordinary dividends declared per share	$ 3.00	$ 3.50	$ 4.00

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Amount authorized for purchase of share under share repurchase plan. Includes, but is not limited to, repurchase of stock and unit of ownership.

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Number of shares that have been repurchased during the period and have not been retired and are not held in treasury. Some state laws may govern the circumstances under which an entity may acquire its own stock and prescribe the accounting treatment therefore. This element is used when state law does not recognize treasury stock.

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Equity impact of the value of stock that has been repurchased during the period and has not been retired and is not held in treasury. Some state laws may mandate the circumstances under which an entity may acquire its own stock and prescribe the accounting treatment therefore. This element is used when state law does not recognize treasury stock.

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