Reconciliations of Equity - Reconciliations of Total Equity (Parenthetical) (Detail) - $ / shares	3 Months Ended		9 Months Ended
	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2022	Sep. 30, 2021
Number of shares of common stock issued under stock option plan	2,734	0	5,381	16,565
Number of common stock shares purchased	54,780	53,058	222,720	135,103
Common stock	$ 0.335	$ 0.305	$ 1.005	$ 0.915
Common Stock [Member]
Number of shares of common stock issued under stock option plan	2,734		5,381	16,565
Additional Paid-in Capital [Member]
Number of shares of common stock issued under stock option plan	2,734		5,381	16,565
Common Treasury Stock [Member]
Number of common stock shares purchased	54,780	53,058	222,720	135,103
Retained Earnings [Member]
Common stock	$ 0.335	$ 0.305	$ 1.005	$ 0.915