Note 9. Income Taxes Components of Income Tax Expense / Benefit (Details) - USD ($) $ in Millions	3 Months Ended								12 Months Ended
	Dec. 31, 2021	Sep. 30, 2021	Jun. 30, 2021	Mar. 31, 2021	Dec. 31, 2020	Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2020	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Income Tax Disclosure [Abstract]
Current Federal Tax Expense (Benefit), CARES Act									$ 2.1	$ (373.3)	$ 0.0
Current Federal Tax Expense (Benefit), Other									(3.0)	(142.1)	(6.8)
Current Federal Tax Expense (Benefit)									(0.9)	(515.4)	(6.8)
Current State and Local Tax Expense (Benefit)									(0.6)	(1.5)	6.9
Current Foreign Tax Expense (Benefit)									4.3	4.3	6.1
Current Income Tax Expense (Benefit)									2.8	(512.6)	6.2
Deferred Tax Expense (Benefit), CARES Act									0.4	192.9	0.0
Deferred Other Tax Expense (Benefit)									10.4	31.3	40.4
Deferred Federal Income Tax Expense (Benefit)									10.8	224.2	40.4
Deferred State and Local Income Tax Expense (Benefit)									2.4	4.1	13.7
Deferred Foreign Income Tax Expense (Benefit)									(0.1)	10.2	(1.5)
Provision for deferred income taxes									13.1	238.5	52.6
Provision (benefit) for income taxes:	$ 6.5	$ 8.3	$ (2.9)	$ 4.0	$ (42.3)	$ (8.7)	$ (74.0)	$ (149.1)	$ 15.9	$ (274.1)	$ 58.8