Stock-Based Compensation (Tables)

3 Months Ended

Mar. 31, 2024

Share-Based Payment Arrangement [Abstract]

Summary of Compensation Expense

Stock-based compensation cost by award type follows:

(in millions)	Three Months Ended March 31,
	2024		2023
Stock option awards	$	3.8	$	3.8
Performance share awards	2.4		2.2
Restricted stock awards	3.5		3.0
Total stock-based compensation cost incurred	9.7		9.0
Capitalized cost during the period	(0.9)		(1.2)
Amortization of capitalized cost during the period	1.0		1.3
Total stock-based compensation expense	$	9.8	$	9.1