Leases - Components of Leases (Details) - USD ($) $ in Millions	Jun. 30, 2019	Dec. 31, 2018	[1]
Leases [Abstract]
Operating lease right-of-use assets	$ 112.6
Operating lease liabilities	$ 125.8	$ 0.0
Operating lease weighted-average remaining lease term	10 years 4 months 20 days
Operating lease weighted-average discount rate	3.87%

[1] Derived from audited consolidated financial statements.