(Schedule of Carrying Amount and Fair Value of Long-term Debt) (Details) - USD ($) $ in Millions	Dec. 31, 2021	Dec. 25, 2020	Apr. 07, 2020	Nov. 05, 2019	Aug. 31, 2014	Apr. 30, 2013
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long term debt	$ 4,267.9	$ 3,944.3
Long-term Debt, Current Maturities	1,395.0	3,622.6
Long-term Debt, Gross	0.0	0.0
Debt, Long-term and Short-term, Combined Amount	5,145.8	5,283.3
Secured Debt	3,485.1	3,622.6
Debt, Long-term and Short-term, Combined Amount	1,660.7	1,660.7
9.50% debentures due May 2022
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Debt, Long-term and Short-term, Combined Amount	10.4	10.4
5.75% senior notes due August 2022
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Debt, Long-term and Short-term, Combined Amount	610.3	610.3
8.00% debentures due March 2023
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Debt, Long-term and Short-term, Combined Amount	4.4	4.4
4.75% senior notes due April 2023
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Debt, Long-term and Short-term, Combined Amount	133.7	133.7
Five Point Five Percent Notes [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Debt, Long-term and Short-term, Combined Amount	387.2	387.2
2017 Revolving Credit Facility
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Secured Debt	900.0	900.0
Five Point Six Two Five Percent Note
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Debt, Long-term and Short-term, Combined Amount	514.7	514.7
Term Loan due 2025 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Secured Debt	370.7	399.5
Term Loan due Sept 2024 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Secured Debt	1,396.5	1,505.2
Ten Point Zero Percent Second Lien Notes [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Secured Debt	322.9	322.9
Ten Point Zero Percent First Lien Notes [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Secured Debt	495.0	495.0
Stated interest rate			10.00%
Secured Debt | Term Loan due 2025 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long term debt	347.7	367.9
Secured Debt		399.5
Secured Debt | Term Loan due Sept 2024 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long term debt	1,309.2	1,386.9
Secured Debt		1,505.2
Secured Debt | Ten Point Zero Percent Second Lien Notes [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Stated interest rate				10.00%
Debentures | 9.50% debentures due May 2022
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long term debt	$ 7.7	4.2
Debt, Long-term and Short-term, Combined Amount		10.4
Stated interest rate	9.50%
Debentures | 8.00% debentures due March 2023
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long term debt	$ 3.2	1.3
Debt, Long-term and Short-term, Combined Amount		4.4
Stated interest rate	8.00%
Senior Notes | 5.75% senior notes due August 2022
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long term debt	$ 324.1	191.2
Stated interest rate	5.75%				5.75%
Debt, Long-term and Short-term, Combined Amount	$ 610.3	610.3
Senior Notes | 4.75% senior notes due April 2023
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long term debt	$ 48.9	11.1
Debt, Long-term and Short-term, Combined Amount		133.7
Stated interest rate	4.75%					4.75%
Senior Notes | Five Point Five Percent Notes [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Stated interest rate	5.50%
Senior Notes | Ten Point Zero Percent Second Lien Notes [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Stated interest rate	10.00%
Debentures | Five Point Five Percent Notes [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long term debt	$ 211.6	115.4
Debt, Long-term and Short-term, Combined Amount		387.2
Debentures | 2017 Revolving Credit Facility
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long term debt	900.0	900.0
Debt, Long-term and Short-term, Combined Amount		900.0
Debentures | Five Point Six Two Five Percent Note
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long term debt	$ 279.1	158.9
Debt, Long-term and Short-term, Combined Amount		514.7
Stated interest rate	5.625%
Debentures | Ten Point Zero Percent Second Lien Notes [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long term debt	$ 312.7	279.0
Debt, Long-term and Short-term, Combined Amount		322.9
Debentures | Ten Point Zero Percent First Lien Notes [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long term debt	$ 523.7	528.4
Debt, Long-term and Short-term, Combined Amount		$ 495.0
Fair Value, Inputs, Level 1 [Member] | Senior Notes | 5.75% senior notes due August 2022
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Stated interest rate	5.75%
Fair Value, Inputs, Level 1 [Member] | Senior Notes | 4.75% senior notes due April 2023
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Stated interest rate	4.75%
Fair Value, Inputs, Level 1 [Member] | Senior Notes | Ten Point Zero Percent Second Lien Notes [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Stated interest rate	10.00%
Fair Value, Inputs, Level 1 [Member] | Debentures | Five Point Five Percent Notes [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Stated interest rate	5.50%
Fair Value, Inputs, Level 1 [Member] | Debentures | Five Point Six Two Five Percent Note
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Stated interest rate	5.625%