Debt (Details) - USD ($) $ in Millions	Sep. 25, 2020	Dec. 27, 2019
Current maturities of long-term debt
Debt Issuance Costs, Current, Net		$ 0.9
Long-term Debt, Current Maturities		634.5
Long-term debt
Long-term Debt	$ 0.0	4,788.3
Total Debt	5,288.2	5,422.8
Debt Issuance Costs	0.0	47.1
Total Debt Issuance Costs	46.9	48.0
Term Loan due 2025 \| Secured Debt
Current maturities of long-term debt
Debt Issuance Costs, Current, Net	5.3	0.1
Long-term Debt, Current Maturities	400.5	4.1
Long-term debt
Long-term Debt	0.0	399.5
Debt Issuance Costs	0.0	6.1
Loans Payable	400.5	403.6
Term Loan due 2024 \| Secured Debt
Current maturities of long-term debt
Debt Issuance Costs, Current, Net	13.1	0.2
Long-term Debt, Current Maturities	1,509.1	15.6
Long-term debt
Long-term Debt	0.0	1,505.2
Debt Issuance Costs	0.0	15.5
Loans Payable	1,509.1	1,520.8
4.88% Senior Notes \| Unsecured Debt
Current maturities of long-term debt
Debt Issuance Costs, Current, Net	0.0	0.6
Long-term Debt, Current Maturities	0.0	614.8
Long-term debt
Long-term Debt		614.8
9.50% Debenture \| Debentures
Current maturities of long-term debt
Debt Issuance Costs, Current, Net	0.0	0.0
Long-term Debt, Current Maturities	10.4	0.0
Long-term debt
Long-term Debt	0.0	10.4
Debt Issuance Costs	0.0	0.0
5.75% Senior Notes \| Unsecured Debt
Current maturities of long-term debt
Debt Issuance Costs, Current, Net	2.5	0.0
Long-term Debt, Current Maturities	610.3	0.0
Long-term debt
Long-term Debt	0.0	610.3
Debt Issuance Costs	0.0	3.7
8.00% Debenture \| Debentures
Current maturities of long-term debt
Debt Issuance Costs, Current, Net	0.0	0.0
Long-term Debt, Current Maturities	4.4	0.0
Long-term debt
Long-term Debt	0.0	4.4
Debt Issuance Costs	0.0	0.0
4.75% Senior Notes \| Unsecured Debt
Current maturities of long-term debt
Debt Issuance Costs, Current, Net	0.6	0.0
Long-term Debt, Current Maturities	133.7	0.0
Long-term debt
Long-term Debt	0.0	133.7
Debt Issuance Costs	0.0	0.8
5.625% Senior Notes \| Unsecured Debt
Current maturities of long-term debt
Debt Issuance Costs, Current, Net	3.6	0.0
Long-term Debt, Current Maturities	514.7	0.0
Long-term debt
Long-term Debt	0.0	514.7
Debt Issuance Costs	0.0	4.4
5.50% Senior Notes \| Unsecured Debt
Current maturities of long-term debt
Debt Issuance Costs, Current, Net	3.1	0.0
Long-term Debt, Current Maturities	387.2	0.0
Long-term debt
Long-term Debt	0.0	387.2
Debt Issuance Costs	0.0	3.6
2017 Revolving Credit Facility \| Secured Debt
Current maturities of long-term debt
Debt Issuance Costs, Current, Net	2.0	0.0
Long-term Debt, Current Maturities	900.0	0.0
Long-term debt
Long-term Debt	0.0	900.0
Debt Issuance Costs	0.0	3.1
10.00% Second Lien Senior Notes \| Unsecured Debt
Current maturities of long-term debt
Debt Issuance Costs, Current, Net	8.5	0.0
Long-term Debt, Current Maturities	322.9	0.0
Long-term debt
Long-term Debt	0.0	322.9
Debt Issuance Costs	0.0	9.9
10.00% First Lien Senior Notes \| Unsecured Debt
Current maturities of long-term debt
Debt Issuance Costs, Current, Net	8.2	0.0
Long-term Debt, Current Maturities	495.0	0.0
Long-term debt
Long-term Debt	0.0	0.0
Debt Issuance Costs	$ 0.0	$ 0.0

Amount, before unamortized (discount) premium and debt issuance costs, of long-term debt. Includes, but is not limited to, notes payable, bonds payable, commercial loans, mortgage loans, convertible debt, subordinated debt and other types of debt.

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