Pensions and Postretirement Benefits Other Than Pensions (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended
	Mar. 31, 2012	Mar. 31, 2011
Components of net periodic benefit cost (Income) :
Curtailment loss	$ 1.5
Weighted average assumptions used to determine net periodic benefit cost
Discount rate	4.67%	5.29%
U.S. Plans [Member]
Components of net periodic benefit cost (Income) :
Service cost	14.2	12.2
Interest cost	42.0	43.1
Expected return on plan assets	(54.3)	(52.6)
Amortization of prior service cost	1.9	1.6
Amortization of actuarial loss	18.9	15.6
Gross periodic benefit cost (income)	22.7	19.9
Net periodic benefit cost (income)	22.7	19.9
Weighted average assumptions used to determine net periodic benefit cost
Discount rate	5.03%	5.67%
Expected long-term rate of return on assets	8.25%	8.25%
Rate of compensation increase	4.10%	4.10%
U.K. Plans [Member]
Components of net periodic benefit cost (Income) :
Service cost	5.0	4.2
Interest cost	11.0	10.8
Expected return on plan assets	(16.0)	(15.4)
Amortization of prior service cost	(0.1)	(0.1)
Amortization of actuarial loss	3.4	0.4
Gross periodic benefit cost (income)	3.3	(0.1)
Net periodic benefit cost (income)	3.3	(0.1)
Termination benefit charge		0.7
Weighted average assumptions used to determine net periodic benefit cost
Discount rate	5.00%	5.81%
Expected long-term rate of return on assets	8.25%	8.25%
Rate of compensation increase	3.75%	3.75%
Other Plans [Member]
Components of net periodic benefit cost (Income) :
Service cost	2.4	1.7
Interest cost	2.2	2.0
Expected return on plan assets	(2.3)	(2.1)
Amortization of prior service cost	0.1	0.1
Amortization of actuarial loss	1.2	0.6
Gross periodic benefit cost (income)	3.6	2.3
Curtailment loss	1.5
Net periodic benefit cost (income)	$ 5.1	2.3
Weighted average assumptions used to determine net periodic benefit cost
Discount rate	4.38%	5.19%
Expected long-term rate of return on assets	8.07%	8.08%
Rate of compensation increase	3.43%	3.40%