Borrowing Arrangements (Fair Value Adjustment) (Details) $ in Millions	12 Months Ended
	Dec. 31, 2016 USD ($)
Debt Disclosure [Abstract]
Unamortized fair value adjustment related to long-term debt	$ 25.2
Amortization of fair value adjustment	10.7
Estimated aggregate amortization of fair value adjustment related to long-term debt (reduction of interest expense) for each of the next five years:
2017	6.9
2018	3.1
2019	2.3
2020	1.9
2021	$ 1.3