Earnings per Share - Composition of Weighted-Average Common Shares (Denominator) Used in Basic and Diluted Earnings Per Share (Detail) - $ / shares	3 Months Ended		6 Months Ended
	Jun. 30, 2022	Jun. 30, 2021	Jun. 30, 2022	Jun. 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)	(19,666,599)	(17,695,829)	(19,660,488)	(17,707,057)
Weighted Average Number of Shares, Deferred Compensation Plans	(55,713)	(55,582)	(55,698)	(55,563)
Average unearned nonvested shares	(172,350)	(150,663)	(149,408)	(132,474)
Weighted average common shares and common stock equivalents used to calculate basic earnings per share (in shares)	94,020,240	96,012,828	94,049,308	96,019,808
Additional common stock equivalents (nonvested stock) used to calculate diluted earnings per share	169,779	213,982	168,749	180,052
Weighted Average Number Of Additional Shares Deferred Compensation Plan	55,751	55,615	55,751	55,615
Weighted average common shares and common stock equivalents used to calculate diluted earnings per share (in shares)	94,245,770	96,282,425	94,273,808	96,255,475
Basic Earnings per Share (in dollars per share)	$ 0.33	$ 0.31	$ 0.62	$ 0.72
Diluted Earnings per Share (in dollars per share)	$ 0.33	$ 0.31	$ 0.62	$ 0.72