Statements of Consolidated Shareholders' Deficit - USD ($) $ in Millions	Total	Preferred Stock	Common Stock	Capital Surplus	Accumulated Deficit	Accumulated Other Comprehensive Loss	Treasury Stock, At Cost
Beginning balance at Dec. 31, 2018	$ (305.5)	$ 0.0	$ 0.3	$ 2,327.6	$ (2,208.4)	$ (332.3)	$ (92.7)
Equity-based compensation	5.3	0.0		5.3
Net loss	(104.0)	0.0			(104.0)
Amortization of prior net losses	12.9	0.0				12.9
Amortization of prior service credit	(0.4)	0.0				(0.4)
Settlement adjustment	1.8	0.0				1.8
Net actuarial gain (loss)	(51.7)	0.0				(51.7)
Foreign currency translation	0.4	0.0				0.4
Ending balance at Dec. 31, 2019	(441.2)	0.0	0.3	2,332.9	(2,312.4)	(369.3)	(92.7)
Equity-based compensation	4.2	0.0		4.2
Equity issuance - UST commitment fee	46.7	0.0	0.2	46.5
Net loss	(53.5)	0.0			(53.5)
Amortization of prior net losses	12.7	0.0				12.7
Amortization of prior service credit	(0.4)	0.0				(0.4)
Settlement adjustment	2.7	0.0				2.7
Net actuarial gain (loss)	204.6	0.0				204.6
Foreign currency translation	0.9	0.0				0.9
Ending balance at Dec. 31, 2020	(223.3)	0.0	0.5	2,383.6	(2,365.9)	(148.8)	(92.7)
Equity-based compensation	4.7	0.0		4.7
Net loss	(109.1)	0.0			(109.1)
Amortization of prior net losses	12.1	0.0				12.1
Amortization of prior service credit	(0.4)	0.0				(0.4)
Settlement adjustment	64.7	0.0				64.7
Net actuarial gain (loss)	(112.7)	0.0				(112.7)
Foreign currency translation	0.5	0.0				0.5
Ending balance at Dec. 31, 2021	$ (363.5)	$ 0.0	$ 0.5	$ 2,388.3	$ (2,475.0)	$ (184.6)	$ (92.7)