Income Taxes Reconciliation of Expected Federal Income Tax Benefit to Income Tax Provision (Benefit) (Details) - USD ($) $ in Millions	3 Months Ended	9 Months Ended	12 Months Ended
	Apr. 01, 2017	Dec. 31, 2017	Dec. 31, 2019	Dec. 31, 2018
Reconciliation of Expected Feferal Income Tax Benefit to the Company's Income Tax Provision (Benefit) [Line Items]
Expected income tax (benefit) expense at U.S. federal statutory rate	$ (160.8)	$ 193.2	$ (29.9)	$ 139.5
Changes in valuation allowance, income tax	(777.2)	(744.9)	(32.0)	(284.6)
Remeasurement due to the Tax Cuts and Jobs Act	0.0	473.5	0.0	9.5
Reorganization costs	2,130.0	0.0	0.0	0.0
Bad debt deduction	(1,639.6)	0.0	0.0	0.0
Changes in tax reserves	(9.2)	7.2	3.0	2.1
Excess depletion	(11.2)	(40.4)	(19.3)	(28.5)
Foreign earnings repatriation	0.0	0.0	76.1	0.0
Foreign earnings provision differential	158.2	(26.3)	45.6	97.1
Global intangible low-taxed income	0.0	0.0	6.1	68.2
Remeasurement of foreign income tax accounts	9.4	(0.3)	(0.1)	(0.2)
State income taxes, net of federal tax benefit	40.6	(3.1)	(13.2)	3.2
Other, net	(4.0)	(19.9)	9.7	12.1
Total income tax provision (benefit)	$ (263.8)	$ (161.0)	$ 46.0	$ 18.4