Reconciliations of Equity - Reconciliations of Total Equity (Parenthetical) (Detail) - $ / shares	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Number of shares of common stock issued under stock option plan	1,514	5,786
Number of common stock shares purchased	98,206	8,300
Common stock	$ 0.335	$ 0.305
Common Stock [Member]
Number of shares of common stock issued under stock option plan	1,514	5,786
Additional Paid-in Capital [Member]
Number of shares of common stock issued under stock option plan	1,514	5,786
Common Treasury Stock [Member]
Number of common stock shares purchased	98,206	8,300
Retained Earnings [Member]
Common stock	$ 0.335	$ 0.305