CONSOLIDATED STATEMENTS OF SHAREHOLDERS’ EQUITY - USD ($) $ in Millions	Total	Preferred stock	Common stock	Additional paid-in capital	Treasury stock, at cost	Accumulated other comprehensive loss	Accumulated deficit
Balance, start at Dec. 31, 2020	$ 546.1	$ 0.0	$ 1.0	$ 2,530.0	$ (86.3)	$ (118.8)	$ (1,779.8)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss)	(227.5)						(227.5)
Other comprehensive income (loss)	3.6					3.6
Share-based compensation	2.6		0.0	2.6
Capped call premiums	(4.6)			(4.6)
Balance, end at Sep. 30, 2021	320.2	0.0	1.0	2,528.0	(86.3)	(115.2)	(2,007.3)
Balance, start at Jun. 30, 2021	370.4	0.0	1.0	2,527.0	(86.3)	(116.4)	(1,954.9)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss)	(52.4)						(52.4)
Other comprehensive income (loss)	1.2					1.2
Share-based compensation	1.0			1.0
Balance, end at Sep. 30, 2021	320.2	0.0	1.0	2,528.0	(86.3)	(115.2)	(2,007.3)
Balance, start at Dec. 31, 2021	421.0	0.0	1.0	2,535.5	(86.3)	(82.3)	(1,946.9)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss)	99.4						99.4
Other comprehensive income (loss)	(5.9)					(5.9)
Share-based compensation	2.1			2.1
Balance, end at Sep. 30, 2022	516.6	0.0	1.0	2,537.6	(86.3)	(88.2)	(1,847.5)
Balance, start at Jun. 30, 2022	479.0	0.0	1.0	2,537.0	(86.3)	(80.9)	(1,891.8)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss)	44.3						44.3
Other comprehensive income (loss)	(7.3)					(7.3)
Share-based compensation	0.6			0.6
Balance, end at Sep. 30, 2022	$ 516.6	$ 0.0	$ 1.0	$ 2,537.6	$ (86.3)	$ (88.2)	$ (1,847.5)