Share-based payments	9 Months Ended
	Sep. 30, 2023
Share-Based Payment Arrangement [Abstract]
Share-based payments	Share-based payments. As part of its incentive compensation program for executives and senior management employees, the Company provides share-based awards, which usually include a combination of time-based restricted stock units, performance-based restricted stock units and stock options. Each restricted stock unit represents a contractual right to receive a share of the Company's Common Stock. The time-based units generally vest on each of the first three anniversaries of the grant date, while the performance-based units vest upon achievement of certain financial objectives and an employee service requirement over a period of approximately three years. The stock options vest on each of the first three anniversaries of the grant date at a rate of 20%, 30% and 50%, chronologically, and expire 10 years after the grant date. Each vested stock option can be exercised to purchase a share of the Company's Common Stock at the strike price set by the Company at the grant date. The compensation expense associated with the share-based awards is calculated based on the fair value of the related award and recognized over the corresponding vesting period.During the first nine months of 2023 and 2022, the Company granted time-based and performance-based restricted stock units with aggregate grant-date fair values of $12.1 million (296,000 units with an average grant price per unit of $41.03) and $11.7 million (183,000 units with an average grant price per unit of $63.68).