Pension and Other Post-Retirement Benefit Plans (Narrative) (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Defined Benefit Plan Disclosure [Line Items]
Company contributions	$ 62.7	$ 114.1
Deferred compensation investments	35.6	32.8
FMC Technologies stock held in trust	7.8	5.8
U.S. Pensions
Defined Benefit Plan Disclosure [Line Items]
Company contributions	31.9	52.8
U S qualified plan U K and Canadian plans
Defined Benefit Plan Disclosure [Line Items]
Item as a percentage of total pension assets (as a percent)	88.00%
International pension plans and nonqualified pension plan
Defined Benefit Plan Disclosure [Line Items]
Expected contributions	30.6
U S qualified pension plan
Defined Benefit Plan Disclosure [Line Items]
Expected contributions	19.0
Company contributions	13.5	51.0
Nonelective contributions
Defined Benefit Plan Disclosure [Line Items]
Vesting service	3 years
Expenses recognized	11.8	8.4
Non qualified pension plan
Defined Benefit Plan Disclosure [Line Items]
Deferred compensation liability	34.4	35.1
Deferred compensation investments	26.0	26.2
Matching contribution
Defined Benefit Plan Disclosure [Line Items]
Expenses recognized	18.4	14.6	11.1
Maximum
Defined Benefit Plan Disclosure [Line Items]
Vesting service for current nonunion employees	5 years
Vesting service	4 years
Level 3 | Limited partnerships | U.S. Pensions
Defined Benefit Plan Disclosure [Line Items]
Prior period reclassification adjustment		$ 4.3