Pension and Other Post Retirement Benefits (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012
Amounts recognized in balance sheet
Noncurrent assets	$ 252.6	$ 78.4
Noncurrent liabilities	(69.8)	(75.6)
U.S. qualified pension plan [Member]
Defined Benefit Plan, Change in Benefit Obligation [Roll Forward]
Beginning balance	1,080.3	909.9
Interest cost	42.9	42.5
Actuarial (gains) and losses	(148.5)	135.0
Benefits paid	(21.2)	(7.1)
Projected benefit obligation at the end of the period	949.4	1,080.3
Total recognized in net periodic benefit cost and OCI
Discount rate	4.89%	4.69%
Reconciliation of funded status to net amounts recognized:
Funded status (deficit)	230.0	68.7
Net amounts recognized	230.0	68.7
Amounts recognized in balance sheet
Noncurrent assets	231.1	69.9
Noncurrent liabilities	(1.1)	(1.2)
Net amounts recognized	230.0	68.7
Amounts not yet reflected in net periodic benefit cost and included in AOCI:
Accumulated gain (loss)	(89.7)	(221.5)
Accumulated other comprehensive income (AOCI)	(89.7)	(221.5)
Cumulative employer contributions in excess of net periodic benefit cost	319.7	290.2
Net amount recognized in the balance sheet	230.0	68.7
Information for pension plans with benefit obligations in excess of plan assets:
Projected benefit obligation/APBO	1.1	1.2
Accumulated benefit obligation	1.1	1.2
Pension and Other Postretirement Benefit Plans, Accumulated Other Comprehensive Income (Loss), Net Gains (Losses), before Tax	(89.7)	(221.5)
U.S. qualified pension plan [Member] | Fair Value [Member]
Defined Benefit Plan, Change in Benefit Obligation [Roll Forward]
Benefits paid	(21.2)	(7.1)
Change in fair value of plan assets:
Beginning balance	1,149.0	1,027.2
Actual return on assets	51.5	130.9
Expenses paid	0	(2.0)
Ending balance	1,179.3	1,149.0
U.K. pension plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Curtailments	(13.1)	0
Defined Benefit Plan, Change in Benefit Obligation [Roll Forward]
Beginning balance	70.3	57.2
Service cost	7.2	7.4
Interest cost	3.2	2.8
Actuarial (gains) and losses	9.6	(0.2)
Benefits paid	(0.6)	(0.3)
Rebates from U.K. Government	0	0.2
Exchange rate changes	1.6	3.1
Projected benefit obligation at the end of the period	78.3	70.3
Total recognized in net periodic benefit cost and OCI
Discount rate	4.75%	4.70%
Salary increases	3.25%	3.10%
Change in fair value of plan assets:
Employee contributions	0.1	0.1
Rebates from U.K. Government	0	0.2
Reconciliation of funded status to net amounts recognized:
Funded status (deficit)	21.5	8.5
Net amounts recognized	21.5	8.5
Amounts recognized in balance sheet
Noncurrent assets	21.5	8.5
Net amounts recognized	21.5	8.5
Amounts not yet reflected in net periodic benefit cost and included in AOCI:
Accumulated gain (loss)	4.4	8.9
Accumulated other comprehensive income (AOCI)	4.4	8.9
Prepaid (unfunded accrued) pension cost	17.1	(0.4)
Net amount recognized in the balance sheet	21.5	8.5
U.K. pension plan [Member] | Fair Value [Member]
Defined Benefit Plan, Change in Benefit Obligation [Roll Forward]
Benefits paid	(0.6)	(0.3)
Rebates from U.K. Government	0	0.9
Change in fair value of plan assets:
Beginning balance	78.8	57.7
Actual return on assets	9.9	8.1
Company contributions	9.0	9.0
Employee contributions	0.1	0.1
Rebates from U.K. Government	0	0.9
Exchange rate changes	2.5	3.3
Ending balance	99.7	78.8
Postretirement Medical Plan [Member]
Defined Benefit Plan, Change in Benefit Obligation [Roll Forward]
Beginning balance	75.7	83.8
Service cost	2.8	3.3
Interest cost	2.1	3.5
Actuarial (gains) and losses	(8.6)	(14.7)
Benefits paid	(0.4)	(0.2)
Projected benefit obligation at the end of the period	71.6	75.7
Total recognized in net periodic benefit cost and OCI
Discount rate	3.89%	2.94%
Medical Assumptions:
Trend assumed for the year	8.05%	8.50%
Ultimate trend rate	4.50%	4.50%
Year that ultimate trend rate is reached	2030	2030
Reconciliation of funded status to net amounts recognized:
Funded status (deficit)	71.6	75.7
Net amounts recognized	71.6	75.7
Amounts recognized in balance sheet
Noncurrent assets	0	0
Current liabilities	(2.9)	(1.3)
Noncurrent liabilities	(68.7)	(74.4)
Net amounts recognized	(71.6)	(75.7)
Amounts not yet reflected in net periodic benefit cost and included in AOCI:
Accumulated gain (loss)	4.2	(4.4)
Accumulated other comprehensive income (AOCI)	4.2	(4.4)
Cumulative employer contributions in excess of net periodic benefit cost	(75.8)	(71.2)
Net amount recognized in the balance sheet	(71.6)	(75.6)
Information for pension plans with benefit obligations in excess of plan assets:
Projected benefit obligation/APBO	71.6	75.7
Pension and Other Postretirement Benefit Plans, Accumulated Other Comprehensive Income (Loss), Net Gains (Losses), before Tax	4.2	(4.4)
Postretirement Medical Plan [Member] | Fair Value [Member]
Defined Benefit Plan, Change in Benefit Obligation [Roll Forward]
Benefits paid	(0.4)	(0.2)
Change in fair value of plan assets:
Company contributions	$ 0.4	$ 0.2