Stock-Based Compensation (Tables)

9 Months Ended

Sep. 30, 2023

Share-Based Payment Arrangement [Abstract]

Summary of Compensation Expense

Stock-based compensation cost by award type follows:

(in millions)	Three Months Ended September 30,				Nine Months Ended September 30,
	2023		2022		2023		2022
Stock option awards	$	3.6	$	1.6	$	11.0	$	5.7
Performance share awards	2.2		1.8		6.8		6.5
Restricted stock awards	1.8		1.1		6.6		5.6
Total stock-based compensation cost incurred	7.6		4.5		24.4		17.8
Capitalized cost during the period	(1.1)		—		(3.4)		—
Amortization of capitalized cost during the period	1.1		—		3.6		—
Total stock-based compensation expense	$	7.6	$	4.5	$	24.6	$	17.8