Note 9. Income Taxes Components of Income Tax Expense / Benefit (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Income Tax Disclosure [Abstract]
Current Federal Tax Expense (Benefit), CARES Act	$ (373.3)	$ 0.0	$ 0.0
Current Federal Tax Expense (Benefit), Other	(125.4)	(6.0)	(19.1)
Current Federal Tax Expense (Benefit)	(498.7)	(6.0)	(19.1)
Current State and Local Tax Expense (Benefit)	(0.1)	6.6	(1.5)
Current Foreign Tax Expense (Benefit)	4.3	6.1	5.3
Current Income Tax Expense (Benefit)	(494.5)	6.7	(15.3)
Deferred Tax Expense (Benefit), CARES Act	192.9	0.0	0.0
Deferred Other Tax Expense (Benefit)	23.4	44.0	43.2
Deferred Federal Income Tax Expense (Benefit)	216.3	44.0	43.2
Deferred State and Local Income Tax Expense (Benefit)	(0.4)	12.3	14.7
Deferred Foreign Income Tax Expense (Benefit)	10.2	(1.5)	0.0
Provision for deferred income taxes	226.1	54.8	57.9
Provision (benefit) for income taxes:	$ (268.4)	$ 61.5	$ 42.6