Stock-Based Compensation (Details 2) - USD ($) $ / shares in Units, $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Options outstanding and exercisable
Options Outstanding, Shares	5,784,100
Options Outstanding, Weighted-Average Remaining Contractual Term	6 years 1 month 6 days
Options Outstanding, Weighted-Average Exercise Price	$ 38.79
Options Outstanding, Aggregate Intrinsic Value	$ 46.0
Options Exercisable, Shares	4,188,841
Options Exercisable, Weighted-Average Remaining Contractual Term	5 years 4 months 24 days
Options Exercisable, Weighted-Average Exercise Price (in dollars per share)	$ 41.20
Options Exercisable, Aggregate Intrinsic Value	$ 29.0
Closing stock price (in dollars per share)	$ 43.51
Range of Exercise Price from $13.40-$20.00
Options outstanding and exercisable
Exercise price range, lower range limit	13.40
Exercise price range, upper range limit	$ 20.00
Options Outstanding, Shares	357,700
Options Outstanding, Weighted-Average Remaining Contractual Term	1 year 3 months 18 days
Options Outstanding, Weighted-Average Exercise Price	$ 15.72
Options Outstanding, Aggregate Intrinsic Value	$ 10.0
Options Exercisable, Shares	357,700
Options Exercisable, Weighted-Average Remaining Contractual Term	1 year 3 months 18 days
Options Exercisable, Weighted-Average Exercise Price (in dollars per share)	$ 15.72
Options Exercisable, Aggregate Intrinsic Value	$ 10.0
Range of Exercise Price from $20.01-$62.25
Options outstanding and exercisable
Exercise price range, lower range limit	$ 20.01
Exercise price range, upper range limit	$ 62.25
Options Outstanding, Shares	5,426,400
Options Outstanding, Weighted-Average Remaining Contractual Term	6 years 4 months 24 days
Options Outstanding, Weighted-Average Exercise Price	$ 40.31
Options Outstanding, Aggregate Intrinsic Value	$ 36.0
Options Exercisable, Shares	3,831,141
Options Exercisable, Weighted-Average Remaining Contractual Term	5 years 9 months 18 days
Options Exercisable, Weighted-Average Exercise Price (in dollars per share)	$ 43.58
Options Exercisable, Aggregate Intrinsic Value	$ 19.0
New Accounting Pronouncement, Early Adoption, Effect | Accounting Standards Update 2016-09, Excess Tax Benefit Component [Member]
Options outstanding and exercisable
Excess Tax Benefit from Share-based Compensation, Operating Activities	$ 6.0	$ 1.0	$ 0.0
Restricted Stock Units (RSUs)
Options outstanding and exercisable
Granted, Weighted-Average Grant Date Fair Value (in dollars per share)	$ 43.09	$ 31.20	$ 36.00
Performance Shares
Options outstanding and exercisable
Employee Service Share-based Compensation, Nonvested Awards, Compensation Cost Not yet Recognized	$ 6.0
Granted, Weighted-Average Grant Date Fair Value (in dollars per share)	$ 44.59	$ 45.37	$ 40.62