Note 13. Common Stock and Stock-based Compensation Stockholders Equity (Details) - USD ($) $ / shares in Units, $ in Millions	3 Months Ended					12 Months Ended
	Dec. 31, 2021	Sep. 30, 2021	Jun. 30, 2021	Mar. 31, 2021	Dec. 31, 2020	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019	Sep. 09, 2021	Apr. 29, 2021	Oct. 23, 2020	Mar. 07, 2019
Share-based Payment Arrangement, Expensed and Capitalized, Amount [Line Items]
Treasury Stock, Value, Acquired, Cost Method							$ 193.1	$ 224.7
Stock Repurchase Program, Remaining Authorized Repurchase Amount		$ 0.0
Share-based Payment Arrangement, Cash Used to Settle Award	$ 100.0
Private Share Repurchase Agreement
Share-based Payment Arrangement, Expensed and Capitalized, Amount [Line Items]
Stock Repurchase Program, Number of Shares Authorized to be Repurchased	8,800,000					8,800,000				8,100,000
Stock Repurchase Program, Authorized Amount	$ 250.0					$ 250.0				$ 222.5
Treasury Stock Acquired, Average Cost Per Share	$ 28.49		$ 27.47
Treasury Stock Acquired, Discount Percentage	3.50%					3.50%				3.50%
2020-2021 Share Repurchase Program
Share-based Payment Arrangement, Expensed and Capitalized, Amount [Line Items]
Stock Repurchase Program, Authorized Amount											$ 250.0	$ 250.0
Stock Repurchase Program, Remaining Authorized Repurchase Amount			$ 77.1	$ 145.4	$ 182.2		$ 182.2
Total Shares Repurchased Under Program	9,522,882					9,522,882
Total Shares Repurchased Under Program, Value	$ 250.0					$ 250.0
2021-2022 Share Repurchase Program
Share-based Payment Arrangement, Expensed and Capitalized, Amount [Line Items]
Stock Repurchase Program, Authorized Amount									$ 250.0
Treasury Stock, Value, Acquired, Cost Method						706.6
Stock Repurchase Program, Remaining Authorized Repurchase Amount	$ 98.1	$ 250.0				$ 98.1
Total Shares Repurchased Under Program	5,155,491					5,155,491
Total Shares Repurchased Under Program, Value	$ 151.9					$ 151.9
Accelerated Share Repurchase Program
Share-based Payment Arrangement, Expensed and Capitalized, Amount [Line Items]
Stock Repurchase Program, Authorized Amount	$ 125.0					125.0
Treasury Stock, Shares, Acquired	3,300,000
Treasury Stock, Value, Acquired, Cost Method						125.0
Stock Repurchase Program, Remaining Authorized Repurchase Amount	$ 73.1					$ 73.1
Treasury Stock [Member]
Share-based Payment Arrangement, Expensed and Capitalized, Amount [Line Items]
Treasury Stock, Shares, Acquired		2,815,307				28,500,000	9,300,000	13,700,000
Treasury Stock, Value, Acquired, Cost Method						$ 806.6	$ 193.1	$ 294.7
Treasury Stock [Member] | 2020-2021 Share Repurchase Program
Share-based Payment Arrangement, Expensed and Capitalized, Amount [Line Items]
Treasury Stock, Shares, Acquired			2,440,793	1,291,860	2,974,922
Treasury Stock, Value, Acquired, Cost Method		$ 77.1	$ 68.3	$ 36.8	$ 67.8
Treasury Stock [Member] | 2021-2022 Share Repurchase Program
Share-based Payment Arrangement, Expensed and Capitalized, Amount [Line Items]
Treasury Stock, Shares, Acquired	5,155,491	0				25,200,000
Treasury Stock, Value, Acquired, Cost Method	$ 151.9	$ 0.0				$ 706.6
Treasury Stock [Member] | Accelerated Share Repurchase Program
Share-based Payment Arrangement, Expensed and Capitalized, Amount [Line Items]
Treasury Stock, Shares, Acquired						3,300,000
Treasury Stock, Value, Acquired, Cost Method						$ 100.0
Additional Paid-in Capital [Member]
Share-based Payment Arrangement, Expensed and Capitalized, Amount [Line Items]
Treasury Stock, Value, Acquired, Cost Method								$ 70.0
Additional Paid-in Capital [Member] | Accelerated Share Repurchase Program
Share-based Payment Arrangement, Expensed and Capitalized, Amount [Line Items]
Treasury Stock, Value, Acquired, Cost Method						$ (25.0)