Investments Investments Finance Lease Receivables (Details) - USD ($) $ in Millions	9 Months Ended	12 Months Ended
	Sep. 30, 2019	Dec. 31, 2018
Accounts, Notes, Loans and Financing Receivable [Line Items]
Finance lease receivables sold	$ 0.0	$ 11.1
Gross minimum lease receivables	35.9	39.0
Allowance for credit losses	(0.2)	(0.4)
Estimated unguaranteed residual values	0.3	0.4
Capital Leases Net Investment In Sales Type Leases Minimum Payments To Be Received And Unguaranteed Residual Values	36.0	39.0
Unearned interest income	(2.6)	(3.0)
Unearned residuals	(0.1)	(0.1)
Capital Leases Net Investment In Sales Type Leases Unearned Interest Income And Residuals	(2.7)	(3.1)
Total	$ 33.3	$ 35.9