Leases - Narrative (Details) $ in Millions	3 Months Ended	9 Months Ended
	Sep. 30, 2019 USD ($)	Sep. 30, 2019 USD ($)
Leases [Abstract]
Term of leases	10 years	10 years
Options to extend, term	5 years	5 years
Operating lease, weighted average remaining lease term	5 years	5 years
Operating lease, weighted average discount rate	3.80%	3.80%
Operating lease expense	$ 9.7	$ 28.7
Cash outflow for operating leases	9.3	27.0
Right-of-use assets obtained in exchange for operating lease liabilities	$ 1.8	$ 8.7