Allowance for Credit Losses - Summary of Allowance for Credit Losses (Details) - USD ($) $ in Millions	Mar. 31, 2017	Dec. 31, 2016	Mar. 31, 2016
Allowance for credit losses and recorded investment in financing receivables
Balance at January 1	$ 4.4	$ 4.6	$ 4.6
Balance at March 31	4.4	4.4	4.6
Finance Leases Financing Receivable [Member]
Allowance for credit losses and recorded investment in financing receivables
Balance at January 1	0.3	0.5	0.5
Balance at March 31	0.3	0.3	0.5
Notes Receivable [Member]
Allowance for credit losses and recorded investment in financing receivables
Balance at January 1	4.1	4.1	4.1
Balance at March 31	$ 4.1	$ 4.1	$ 4.1