Earnings per Share - Composition of Weighted-Average Common Shares (Denominator) Used in Basic and Diluted Earnings Per Share (Detail) - $ / shares	3 Months Ended		9 Months Ended
	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2022	Sep. 30, 2021
Earnings Per Share [Abstract]
Weighted Average Number of Shares Issued, Basic	113,914,902	113,914,902	113,914,902	113,914,902
Average treasury shares (in shares)	(20,485,573)	(18,103,611)	(19,938,539)	(17,840,694)
Weighted Average Number of Shares, Deferred Compensation Plans	(55,751)	(55,615)	(55,716)	(55,581)
Average unearned nonvested shares	(178,724)	(139,255)	(159,287)	(134,759)
Weighted average common shares and common stock equivalents used to calculate basic earnings per share (in shares)	93,194,854	95,616,421	93,761,360	95,883,868
Additional common stock equivalents (nonvested stock) used to calculate diluted earnings per share	199,620	220,268	177,013	191,119
Weighted Average Number Of Additional Shares Deferred Compensation Plan	55,785	55,615	55,785	55,615
Weighted average common shares and common stock equivalents used to calculate diluted earnings per share (in shares)	93,450,259	95,892,304	93,994,158	96,130,602
Basic Earnings per Share (in dollars per share)	$ 0.36	$ 0.36	$ 0.99	$ 1.08
Diluted Earnings per Share (in dollars per share)	$ 0.36	$ 0.36	$ 0.98	$ 1.08