Interest Expense (Tables)

9 Months Ended

Sep. 30, 2020

Other Income and Expenses [Abstract]

Summary of Interest and Other Expense

Interest expense, net was as follows: 

	Three Months Ended September 30,				Nine Months Ended September 30,
(in millions)	2020		2019		2020		2019
Contractual coupon interest	$	2.1	$	2.6	$	6.4	$	7.5
Accretion of debt discount	10.6		8.2		31.5		22.2
Amortization of debt issuance costs	0.7		0.7		2.1		2.1
Capitalized interest	(1.5)		(2.1)		(4.7)		(8.1)
Interest expense, net of portion capitalized	11.9		9.4		35.3		23.7
Interest income	(0.5)		(1.7)		(2.7)		(5.4)
Interest expense, net	$	11.4	$	7.7	$	32.6	$	18.3