Shareholders' Equity - Common Stock Activity (Detail) - shares	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Increase (Decrease) in Stockholders' Equity
Common stock, issued, beginning balance (in shares)	113,218,183
Treasury stock, beginning balance (in shares)	(9,420,699)
Grants of restricted stock (in shares)	156,789	161,909	171,974
Vesting of performance shares (in shares)	226,866	282,552	338,873
Issuance of common stock due to exercise of stock options (in shares)	1,191,704	936,289	1,810,559
Common stock, issued, ending balance (in shares)	109,218,183	113,218,183
Treasury stock, ending balance (in shares)	(9,650,845)	(9,420,699)
Performance Shares
Increase (Decrease) in Stockholders' Equity
Grants of restricted stock (in shares)	139,500	151,200	156,500
Common Stock
Increase (Decrease) in Stockholders' Equity
Common stock, issued, beginning balance (in shares)	113,218,183	117,218,183	121,218,183
Treasury stock, beginning balance (in shares)	(9,420,699)	(9,497,940)	(10,525,147)
Grants of restricted stock (in shares)	10,031	4,548	8,840
Issuance of common stock due to exercise of stock options (in shares)	1,191,704	936,289	1,810,559
Treasury stock acquired (in shares)	(5,642,036)	(5,135,439)	(5,103,591)
Retirement of treasury stock (in shares)	4,000,000	4,000,000	4,000,000
Common stock, issued, ending balance (in shares)	109,218,183	113,218,183	117,218,183
Treasury stock, ending balance (in shares)	(9,650,845)	(9,420,699)	(9,497,940)
Common Stock | Performance Shares
Increase (Decrease) in Stockholders' Equity
Vesting of performance shares (in shares)	210,155	271,843	311,399