Leases - Supplemental Cash Flow and Other Information (Details) $ in Millions	3 Months Ended
	Mar. 31, 2019 USD ($)
Leases [Abstract]
Operating lease cost	$ 15.9
Operating cash flows used for operating leases	15.9
Right-of-use assets obtained in exchange for operating lease obligations	$ 18.2
Weighted average remaining lease term - operating leases	7 years
Weighted average discount rate	2.90%