Net Income Per Common Share (Details) (USD $) In Millions, except Per Share data, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2012	Sep. 30, 2011	Sep. 30, 2012	Sep. 30, 2011
Basic net income per share:
Net income attributable to AGCO Corporation and subsidiaries	$ 94.5	$ 84.4	$ 419.6	$ 298.1
Weighted average number of common shares outstanding	97.0	96.4	97.1	95.1
Basic net income per share attributable to AGCO Corporation and subsidiaries	$ 0.97	$ 0.88	$ 4.32	$ 3.13
Diluted net income per share:
Dilutive SSARs, performance share awards and restricted stock awards	1.0	0.2	1.0	0.3
Weighted average assumed conversion of contingently convertible senior subordinated notes	0.4	0.3	0.5	2.5
Weighted average number of common shares and common share equivalents outstanding for purposes of computing diluted income per share	98.4	96.9	98.6	97.9
Diluted net income per share attributable to AGCO Corporation and subsidiaries	$ 0.96	$ 0.87	$ 4.25	$ 3.04
Stock-Settled Stock Appreciation Rights [Member]
Diluted net income per share:
Antidilutive shares excluded from calculation of weighted average common and common equivalent shares outstanding	0.6	0.3	0.6	0.3