Stock-Based Compensation (Tables)

9 Months Ended

Sep. 30, 2022

Share-Based Payment Arrangement [Abstract]

Schedule of Compensation Expense

Stock-based compensation cost by award type follows:

(in millions)	Three Months Ended September 30,				Nine Months Ended September 30,
	2022		2021		2022		2021
Stock option awards	$	2.3	$	1.9	$	7.7	$	7.8
Restricted stock awards	1.3		1.7		6.3		5.6
Performance share awards	2.0		1.7		7.4		6.0
Stock appreciation rights	—		—		—		9.0
Total stock-based compensation cost incurred	5.6		5.3		21.4		28.4
Capitalized cost during the period	—		—		—		(9.3)
Amortization of capitalized cost during the period	—		—		—		14.3
Total stock-based compensation expense	$	5.6	$	5.3	$	21.4	$	33.4