Right-of-Use Lease Assets and Lease Liabilities (Details) $ in Millions	3 Months Ended	9 Months Ended
	Sep. 30, 2019 USD ($)	Sep. 30, 2019 USD ($)
Leases [Abstract]
Operating lease, right-of-use asset	$ 34.1	$ 34.1
Operating lease, liability	34.3	34.3
Operating lease, expense	$ 2.8	$ 8.1
Operating ease, weighted average discount rate, percent	3.47%	3.47%
Operating lease, weighted average remaining lease term	8 years 7 months 17 days	8 years 7 months 17 days