Income Taxes - Summary of Deferred Income Tax Assets and Liabilities (Details) - USD ($) $ in Millions	Dec. 31, 2020	Dec. 31, 2019
Deferred income tax assets:
Federal net operating loss carryforward	$ 488.3	$ 341.4
State net operating loss carryforward	61.0	44.8
Total deferred tax assets, net of valuation allowance	549.3	386.2
Valuation allowance	(153.3)	0.0
Total deferred tax assets, net of valuation allowance	396.0	386.2
Deferred tax liabilities:
Property, plant, equipment, and intangible assets	504.6	354.0
Total deferred tax liabilities	504.6	354.0
Deferred tax asset (liability), net	$ (108.6)
Deferred tax asset (liability), net		$ 32.2