Common Stock (Tables)

12 Months Ended

Dec. 31, 2021

Equity [Abstract]

Common Stock and Treasury Stock Activity

The number of shares of common stock and treasury stock and the share activity for 2021 and 2020 were as follows:

	Common Shares						Treasury Shares
	2021			2020			2021		2020
Balance at the beginning of the year		138,660,154			139,555,487			45,406,158		42,335,315
Stock plan shares issued		1,250,550			2,175,510			—		—
Shares surrendered by optionees		(144,280	)		(159,089	)		144,280		159,089
Common stock repurchases		(4,702,128	)		(2,911,754	)		4,702,128		2,911,754
Balance at the end of the year		135,064,296			138,660,154			50,252,566		45,406,158