Redeemable Noncontrolling Interest (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Business Combination, Step Acquisition [Abstract]
Payments to Acquire Businesses and Interest in Affiliates		$ 45.0
Beginning balance	$ 14.0		$ 0.0	$ 0.0
Ending balance	13.0	0.0	13.0	0.0
Purchase of redeemable common and preferred stock	0.0	0.0	15.0	0.0
Adjustment to redemption value	0.0	0.0	0.0	0.0
Net loss attributable to redeemable noncontrolling interest	(2.0)	0.0	(2.0)	0.0
Gain on acquisition	0.0	$ 0.0	14.0	$ 0.0
Business Combination, Recognized Identifiable Assets Acquired, Goodwill, and Liabilities Assumed, Net	56.0		56.0
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Current Assets	41.0		41.0
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Finite-Lived Intangibles	6.0		6.0
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Indefinite-Lived Intangible Assets	25.0		25.0
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Current Liabilities	(1.0)		(1.0)
Right-of-Use Asset, not yet controlled	18.0		$ 18.0
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Intangible Assets, Other than Goodwill	$ 4.0