Special items Severance and Other Employee Related (Details) (Severance and other employee- related costs, USD $) In Millions, unless otherwise specified	6 Months Ended
	Jun. 30, 2012
Changes in restructuring accruals [Roll Forward]
Beginning balance of restructuring accruals	$ 1.9
Charges incurred	9.0
Payments made	(2.4)
Foreign currency and other adjustments	(0.3)
Ending balance of restructuring accruals	8.2
Canada
Changes in restructuring accruals [Roll Forward]
Beginning balance of restructuring accruals	0.1
Charges incurred	1.6
Payments made	(0.7)
Foreign currency and other adjustments	0
Ending balance of restructuring accruals	1.0
U.K.
Changes in restructuring accruals [Roll Forward]
Beginning balance of restructuring accruals	1.8
Charges incurred	6.3
Payments made	(1.7)
Foreign currency and other adjustments	(0.3)
Ending balance of restructuring accruals	6.1
Corporate
Changes in restructuring accruals [Roll Forward]
Beginning balance of restructuring accruals	0
Charges incurred	1.1
Payments made	0
Foreign currency and other adjustments	0
Ending balance of restructuring accruals	$ 1.1