Accumulated Other Comprehensive Income (Loss) (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended			9 Months Ended
	Sep. 30, 2012	Mar. 31, 2012	Sep. 30, 2011	Sep. 30, 2012	Sep. 30, 2011	Dec. 31, 2011
Stockholders' Equity Note [Abstract]
Decrease in Property and Equipment related to an error correction based on the translation of the Company's functional currency of Argentina operations		$ 2.1
Decrease in Goodwill related to an error correction based on the translation of the Company's functional currency of Argentina operations		4.0
Decrease in Comprehensive Income related to an error correction based on the translation of the Company's functional currency of Argentina operations		6.1
Accumulated other comprehensive loss, net of tax
Foreign currency translation	86.0			86.0		128.8
Pension and other postretirement liability adjustment, net of deferred tax effect	(203.9)			(203.9)		(219.6)
Tax effect of pension liability adjustment	121.1			121.1		130.1
Unrecognized gain on derivative	0			0		0.1
Accumulated other comprehensive income (loss)	(117.9)			(117.9)		(90.7)
Total other comprehensive income (loss)
Comprehensive income (loss) attributable to Bemis Company, Inc.	67.3		(109.4)	106.5	67.6
Comprehensive income (loss) attributable to noncontrolling interest	0		0.3	0	5.3
Total comprehensive income (loss)	$ 67.3		$ (109.1)	$ 106.5	$ 72.9