Goodwill and Other Intangible Assets Textuals (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Amortization of Intangible Assets	$ 15.1	$ 14.3	$ 11.5
Future Amortization Expense, Year One	15.5
Future Amortization Expense, Year Two	14.3
Future Amortization Expense, Year Three	12.8
Future Amortization Expense, Year Four	13.5
Future Amortization Expense, Year Five	11.8
Amortization Of Acquired Intangible Asset Net Of Tax	14.3	13.3	10.9
Purchased Intangibles, Net of Tax	10.8	10.0	7.1
Capitalized Computer Software, Amortization	$ 34.4	$ 33.0	$ 31.0
Minimum [Member]
Finite-Lived Intangible Assets, Useful Life, Minimum	3 years
Maximum [Member]
Finite-Lived Intangible Assets, Useful Life, Minimum	45 years