Property and Equipment (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2011		Dec. 31, 2010
Property, Plant and Equipment [Line Items]
Cost: beginning balance	$ 835.4		$ 739.1
Foreign exchange, cost	(4.8)		0.4
Additions, cost	110.0		100.1	[1]
Transfers, cost	0		0
Disposals, cost	(102.9)		(4.2)
Cost: ending balance	837.7		835.4
Accumulated depreciation: beginning	(563.0)		(518.4)
Foreign exchange, Accumulated depreciation	3.0		(2.4)
Depreciation expense, Accumulated depreciation	(60.3)		(46.4)
Disposals, Accumulated depreciation	95.4		4.2
Accumulated depreciation: ending	(524.9)		(563.0)
Net book value	312.8		272.4
Non-depreciable land assets	33.6		33.2
Additions related to acuired business			5.4
Technology and Other Equipment [Member]
Property, Plant and Equipment [Line Items]
Cost: beginning balance	318.4		282.5
Foreign exchange, cost	(2.2)		1.7
Additions, cost	14.3		10.0	[1]
Transfers, cost	15.8		28.3
Disposals, cost	(79.1)		(4.1)
Cost: ending balance	267.2		318.4
Accumulated depreciation: beginning	(261.7)		(245.5)
Foreign exchange, Accumulated depreciation	1.4		(2.1)
Depreciation expense, Accumulated depreciation	(20.1)		(18.2)
Disposals, Accumulated depreciation	77.7		4.1
Accumulated depreciation: ending	(202.7)		(261.7)
Net book value	64.5		56.7
Software [Member]
Property, Plant and Equipment [Line Items]
Cost: beginning balance	266.1		231.3
Foreign exchange, cost	(0.6)		(1.1)
Additions, cost	3.8		7.4	[1]
Transfers, cost	22.3		28.6
Disposals, cost	(7.6)		(0.1)
Cost: ending balance	284.0		266.1
Accumulated depreciation: beginning	(184.0)		(165.3)
Foreign exchange, Accumulated depreciation	0.7		0.8
Depreciation expense, Accumulated depreciation	(27.9)		(19.6)
Disposals, Accumulated depreciation	8.0		0.1
Accumulated depreciation: ending	(203.2)		(184.0)
Net book value	80.8		82.1
Land and Buildings [Member]
Property, Plant and Equipment [Line Items]
Cost: beginning balance	72.1	[2]	72.5	[2]
Foreign exchange, cost	(0.7)	[2]	(1.4)	[2]
Additions, cost	1.2	[2]	1.0	[1],[2]
Transfers, cost	0	[2]	0	[2]
Disposals, cost	(6.9)	[2]	0	[2]
Cost: ending balance	65.7	[2]	72.1	[2]
Accumulated depreciation: beginning	(8.4)	[2]	(7.5)	[2]
Foreign exchange, Accumulated depreciation	0.1	[2]	0.3	[2]
Depreciation expense, Accumulated depreciation	(1.3)	[2]	(1.2)	[2]
Disposals, Accumulated depreciation	0.5	[2]	0	[2]
Accumulated depreciation: ending	(9.1)	[2]	(8.4)	[2]
Net book value	56.6	[2]	63.7	[2]
Work in Process [Member]
Property, Plant and Equipment [Line Items]
Cost: beginning balance	19.6		11.5
Foreign exchange, cost	(0.5)		(0.1)
Additions, cost	73.7		78.2	[1]
Transfers, cost	(48.6)		(70.0)
Disposals, cost	0		0
Cost: ending balance	44.2		19.6
Accumulated depreciation: beginning	0		0
Foreign exchange, Accumulated depreciation	0		0
Depreciation expense, Accumulated depreciation	0		0
Disposals, Accumulated depreciation	0		0
Accumulated depreciation: ending	0		0
Net book value	44.2		19.6
Leasehold Improvements [Member]
Property, Plant and Equipment [Line Items]
Cost: beginning balance	159.2		141.3
Foreign exchange, cost	(0.8)		1.3
Additions, cost	17.0		3.5	[1]
Transfers, cost	10.5		13.1
Disposals, cost	(9.3)		0
Cost: ending balance	176.6		159.2
Accumulated depreciation: beginning	(108.9)		(100.1)
Foreign exchange, Accumulated depreciation	0.8		(1.4)
Depreciation expense, Accumulated depreciation	(11.0)		(7.4)
Disposals, Accumulated depreciation	9.2		0
Accumulated depreciation: ending	(109.9)		(108.9)
Net book value	$ 66.7		$ 50.3

[1] Included within additions is $5.4 million at December 31, 2010 related to the acquired businesses.

[2] Included within land and buildings are $33.6 million at December 31, 2011 (2010: $33.2 million) in non-depreciable land assets.