Components of Net Periodic Benefit Cost (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Pension Plan, Defined Benefit [Member]
Components of Net Periodic Benefit Cost
Service cost - benefits earned during the period	$ 1.9	$ 2.0	$ 5.8	$ 5.9
Interest cost on projected benefit obligation	8.2	8.6	24.5	25.6
Expected return on plan assets	(12.7)	(12.0)	(38.1)	(36.0)
Settlement loss	0.0	0.9	0.0	1.3
Curtailment loss (gain)	0.0	0.0	0.0	0.9
Amortization of unrecognized transition obligation	0.1	0.1	0.1	0.2
Amortization of prior service cost	0.2	0.3	0.7	1.0
Recognized actuarial net (gain) or loss	5.0	3.0	15.1	8.8
Net periodic benefit (income) cost	2.7	2.9	8.1	7.7
Other Postretirement Benefit Plan, Defined Benefit [Member]
Components of Net Periodic Benefit Cost
Curtailment loss (gain)				(3.0)
Bemis Investment Profit Sharing Plan and Other Defined Contribution Plans [Member]
Components of Net Periodic Benefit Cost
Defined contribution benefits plans	$ 4.9	$ 5.1	$ 14.6	$ 15.6