Financial Instruments (Details 5) (USD $) In Millions, unless otherwise specified	12 Months Ended
Dec. 31, 2011
Future minimum lease payments under capital leases
2012	1.4
2013	1.3
2014	1.3
2015	1.3
2016	1.3
Thereafter	5.0
Total	11.6
Less amount representing interest (at rates ranging from 4.2% to 8.7%)	1.4
Present value of net minimum capital lease payments	10.2
Less current installments of obligations under capital leases	1.1
Obligations under capital leases, excluding installments	9.1
Future minimum lease payments under operating leases
2012	9.3
2013	7.6
2014	5.8
2015	3.6
2016	1.2
Thereafter	3.1
Total	30.6
Minimum
Capital Leases
Interest rate for capital leases (as a percent)	4.20%
Maximum
Capital Leases
Interest rate for capital leases (as a percent)	8.70%

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Amount equal to the present value (the principal) at the beginning of the lease term of minimum lease payments during the lease term (excluding that portion of the payments representing executory costs such as insurance, maintenance, and taxes to be paid by the lessor, together with any profit thereon) net of payments or other amounts applied to the principal, through the balance sheet date and due to be paid within one year (or one operating cycle, if longer) of the balance sheet date.