Fresh-Start Accounting - Reorganization Items (Details) - USD ($) $ in Millions		1 Months Ended	3 Months Ended		6 Months Ended
	Jun. 16, 2022	Jul. 01, 2022	Jun. 16, 2022	Jun. 25, 2021	Jun. 16, 2022	Jun. 25, 2021
Reorganizations [Abstract]
Cash Paid, Reorganization items					$ 304.1	$ 103.4
Reorganization, Chapter 11 [Line Items]
Debtor Reorganization Items, Legal and Advisory Professional Fees		$ 3.5	$ 120.6	$ 109.5	161.1	187.2
Debtor Reorganization Items, Success Fees		0.0	44.3	0.0	44.3	0.0
Debtor Reorganization Items, Net, Prepaid Expense Write-Off		0.0	9.2	0.0	9.2	0.0
Debtor Reorganization Items, Gain (Loss) on Settlement of Other Claims, Net		0.0	2.5	0.0	5.4	(0.5)
Reorganization items, net		3.5	587.5	109.5	630.9	203.0
Debtor Reorganization Items, Write-off of Debt Issuance Costs and Debt Discounts		0.0			0.0	16.3
Reorganization, Chapter 11, Plan Effect Adjustment
Reorganization, Chapter 11 [Line Items]
Gain on settlement of liabilities subject to compromise	$ 943.7	0.0	(943.7)	0.0	(943.7)	0.0
Reorganization, Chapter 11, Fresh-Start Adjustment
Reorganization, Chapter 11 [Line Items]
Reorganization Items, net, Loss on Fresh-Start Adjustments	$ (1,354.6)	$ 0.0	$ 1,354.6	$ 0.0	$ 1,354.6	$ 0.0