Income Taxes Components of Income Tax Expense (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Income before income taxes:
United States	$ 347.2	$ 385.6	$ 360.8
International	71.4	99.9	113.0
Income before income taxes	418.6	485.5	473.8
Provision for income taxes — current:
Federal	110.4	90.1	94.6
State	13.7	15.4	15.1
International	17.6	22.5	21.0
Total provision-current	141.7	128.0	130.7
Provision for income taxes — deferred:
Federal	(1.7)	24.4	14.4
State	0.4	2.7	0.1
International	(3.9)	3.2	(1.2)
Total provision — deferred	(5.2)	30.3	13.3
TOTAL PROVISION FOR INCOME TAXES	$ 136.5	$ 158.3	$ 144.0