Acquisitions (Details 3) (USD $) In Millions, except Per Share data, unless otherwise specified	3 Months Ended								12 Months Ended
	Dec. 31, 2012	Sep. 30, 2012	Jun. 30, 2012	Mar. 31, 2012	Dec. 31, 2011	Sep. 30, 2011	Jun. 30, 2011	Mar. 31, 2011	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Business Acquisition, Pro Forma Information, Nonrecurring Adjustment [Line Items]
Pro forma revenue											$ 5,031.0
Net sales	1,233.9	1,287.8	1,312.7	1,304.8	1,270.2	1,357.9	1,370.2	1,324.4	5,139.2	5,322.7	4,835.0
Pro forma net income											211.9
Net income attributable to Bemis Company, Inc.	$ 40.1	$ 47.4	$ 42.3	$ 44.0	$ 22.8	$ 55.9	$ 54.2	$ 51.2	$ 173.8	$ 184.1	$ 205.1
Pro forma earnings per share, diluted											$ 1.91
Diluted earnings per share, net income	$ 0.38	$ 0.45	$ 0.40	$ 0.42	$ 0.22	$ 0.53	$ 0.51	$ 0.47	$ 1.66	$ 1.73	$ 1.85