Capital Stock (Tables)

12 Months Ended

Dec. 31, 2023

Stockholders' Equity Note [Abstract]

Schedule of Common Stock Outstanding

Common stock outstanding as of December 31, 2023, 2022 and 2021 was as follows:

(Number of shares in millions)	2023		2022		2021
Common stock:
Balance, beginning of year	110.4		110.1		109.7
Activity under stock plans		0.4		0.3		0.4
Balance, end of year	110.8		110.4		110.1
Treasury stock:
Balance, beginning of year	26.2		26.1		26.1
Repurchased		0.5		0.1		—
Balance, end of year	26.7		26.2		26.1
Common stock outstanding		84.1		84.2		84.0