Leases - Components of Leases (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2019	Dec. 31, 2018	[1]
Leases [Abstract]
Operating lease right-of-use assets	$ 115.3
Operating lease liabilities	$ 128.3	$ 0.0
Operating lease weighted-average remaining lease term	10 years 3 months 4 days
Operating lease weighted-average discount rate	3.87%

[1] Derived from audited consolidated financial statements.