Recent Authoritative Accounting Guidance (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Right-of-use assets obtained in exchange for operating lease liabilities	$ 54.6	$ 0.0
Operating Lease, Payments	$ 54.6