Share-based payments

12 Months Ended

Dec. 31, 2023

Share-Based Payment Arrangement [Abstract]

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 employee service requirements 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, calculated based on the fair value of the related award and recognized over the corresponding vesting period, is presented as part of employee costs in the consolidated statement of income and comprehensive income. Award forfeitures are recorded as credits against employee costs in the period in which they occur.

The aggregate grant-date fair value of restricted stock unit awards to employees during 2023, 2022 and 2021 was $12.3 million (299,000 stock units with an average grant price of $41.09), $11.9 million (188,300 stock units with an average grant price of $62.99) and $13.1 million (240,800 stock units with an average grant price of $54.45), respectively. In 2021, the Company granted stock option awards with aggregate grant-date fair value of $1.3 million (140,600 options with an average grant price of $9.24 and exercise strike price of $53.24).

A summary of the restricted stock unit activity during the year ended December 31, 2023 is presented below:


	Units	Weighted-Average Grant-Date Fair Value per Share ($)

Outstanding at January 1, 2023	364,277	57.86
Granted	299,008	41.09

Converted	(130,771)	52.98
Forfeited	(15,479)	66.50
Outstanding at December 31, 2023	517,035	49.14
Unvested at December 31, 2023	502,251	48.85

A summary of the stock option activity during the year ended December 31, 2023 is presented below:


	Units	Weighted-Average Exercise Price ($)

Outstanding at January 1, 2023	693,341	42.37

Exercised	(9,051)	39.76
Forfeited	(9,272)	47.79
Outstanding at December 31, 2023	675,018	42.33
Unvested at December 31, 2023	61,565	53.24

As of December 31, 2023, the aggregate intrinsic value and weighted average remaining contractual term related to outstanding options was $11.1 million and 6.3 years, respectively.

The fair value of grants that vested in 2023 and 2022 aggregated to $5.6 million and $9.6 million, respectively. For the years ended December 31, 2023, 2022 and 2021, compensation costs recognized related to share-based awards to employees were approximately $10.1 million, $11.5 million and $12.0 million, respectively. The total tax benefits recognized in the consolidated statements of income and comprehensive income from tax deductions relating to vesting of equity awards in 2023, 2022 and 2021 were $0.9 million, $1.2 million and $0.8 million, respectively. As of December 31, 2023, compensation costs not yet recognized related to all employee nonvested awards was $9.8 million, which is expected to be recognized over a weighted average period of 1.9 years.