CONSOLIDATED STATEMENTS OF CHANGES IN STOCKHOLDERS' EQUITY (DEFICIT) - USD ($) $ in Millions		Common Stock		Treasury Stock at Cost, Common	Additional Paid-in Capital	Accumulated Other Comprehensive Income (Loss)	Accumulated Income (Deficit)	Total
Balances at beginning of period at Dec. 31, 2019		$ 0.9		$ (79.7)	$ 322.8	$ (15.5)	$ (474.4)	$ (245.9)
Balances at beginning of period (in shares) at Dec. 31, 2019		84,103,108
Increase (Decrease) in Stockholders' Deficit
Changes in accumulated other comprehensive gain (loss)						9.0		9.0
Stock-based compensation		$ 0.1			11.0			11.1
Issuance of restricted stock, net (in shares)		3,004,954
Purchase of shares (in dollars)				$ (1.0)				(1.0)
Purchase of shares (in shares)		(260,265)		260,265
Net income (loss)							14.4	14.4
Balances at end of period at Dec. 31, 2020	[1]	$ 1.0		$ (80.7)	333.8	(6.5)	(460.0)	(212.4)
Balances at end of period (in shares) at Dec. 31, 2020	[1]	86,847,797
Increase (Decrease) in Stockholders' Deficit
Changes in accumulated other comprehensive gain (loss)						$ 6.5		6.5
Stock-based compensation					14.7			14.7
Issuance of restricted stock, net (in shares)		1,038,749
Purchase of shares (in dollars)				$ (8.5)				(8.5)
Purchase of shares (in shares)		(494,458)		494,458
Net income (loss)							770.5	770.5
Balances at end of period at Dec. 31, 2021	[1]	$ 1.0		$ (89.2)	348.5		310.5	$ 570.8
Balances at end of period (in shares) at Dec. 31, 2021		87,392,088	[1]					87,392,088
Increase (Decrease) in Stockholders' Deficit
Stock-based compensation					26.2			$ 26.2
Issuance of restricted stock, net (in shares)		604,402
Purchase of shares (in dollars)				$ (19.4)				(19.4)
Purchase of shares (in shares)		(1,578,757)		1,578,757
Net income (loss)							(2.5)	(2.5)
Balances at end of period at Dec. 31, 2022	[1]	$ 1.0		$ (108.6)	$ 374.7		$ 308.0	$ 575.1
Balances at end of period (in shares) at Dec. 31, 2022		86,417,733	[1]					86,417,733

[1] Included in outstanding shares as of December 31, 2022, 2021 and 2020 are 3,223,995, 4,325,124 and 4,990,971, respectively, of non-vested shares of restricted stock awards granted to employees and directors.