Segmental Reporting (by Segment) (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended				6 Months Ended
	Jun. 30, 2012		Jun. 30, 2011		Jun. 30, 2012		Jun. 30, 2011		Dec. 31, 2011
Segment reporting, operating income/(loss)
Product sales	$ 1,147.7		$ 993.3		$ 2,254.6		$ 1,882.6
Royalties	56.3		63.4		112.6		137.0
Other revenues	3.8		6.2		12.4		15.5
Total revenues	1,207.8		1,062.9		2,379.6		2,035.1
Cost of product sales	152.5	[1]	143.7	[1]	310.9	[1]	268.2	[1]
Research and development	238.6	[1]	176.9	[1]	458.9	[1]	354.8	[1]
Selling, general and administrative ("SG&A")	511.0	[1]	440.3	[1]	1,011.0	[1]	843.2	[1]
(Gain)/loss on sale of product rights	(3.6)		2.2		(10.8)		3.5
Reorganization costs	0		7.5		0		13.0
Integration and acquisition costs	7.1		9.0		12.4		2.6
Total operating expenses	905.6		779.6		1,782.4		1,485.3
Operating income/(loss)	302.2		283.3		597.2		549.8
Assets	7,041.0		6,165.6		7,041.0		6,165.6		6,380.2
Long-lived assets	927.2		908.9		927.2		908.9
Capital expenditure on long-lived assets	36.3		50.9		53.8		94.8
Specialty Pharmaceuticals
Segment reporting, operating income/(loss)
Product sales	735.5		674.7		1,442.2		1,290.8
Royalties	45.4		51.8		87.8		89.3
Other revenues	3.6		4.7		11.9		12.3
Total revenues	784.5		731.2		1,541.9		1,392.4
Cost of product sales	84.8	[2]	93.8	[3]	171.9	[4]	175.7	[5]
Research and development	158.3	[2]	105.0	[3]	289.3	[4]	207.7	[5]
Selling, general and administrative ("SG&A")	311.5	[2]	294.0	[3]	611.6	[4]	560.6	[5]
(Gain)/loss on sale of product rights	(3.6)		2.2		(10.8)		3.5
Reorganization costs			2.7		0		5.0
Integration and acquisition costs	2.8		2.1		4.4		(4.3)
Total operating expenses	553.8		499.8		1,066.4		948.2
Operating income/(loss)	230.7		231.4		475.5		444.2
Assets	2,534.6		2,513.9		2,534.6		2,513.9
Long-lived assets	130.1	[6]	158.1	[6]	130.1	[6]	158.1	[6]
Capital expenditure on long-lived assets	12.1	[6]	18.2	[6]	19.2	[6]	23.1	[6]
Human Genetic Therapies
Segment reporting, operating income/(loss)
Product sales	359.8		316.6		711.2		589.8
Royalties	0		0		0		0
Other revenues	0.2		0.2		0.5		0.5
Total revenues	360.0		316.8		711.7		590.3
Cost of product sales	50.7	[2]	49.6	[3]	112.0	[4]	92.2	[5]
Research and development	76.0	[2]	71.8	[3]	162.3	[4]	147.0	[5]
Selling, general and administrative ("SG&A")	95.9	[2]	91.9	[3]	200.4	[4]	172.0	[5]
(Gain)/loss on sale of product rights	0		0		0		0
Reorganization costs			0		0		0
Integration and acquisition costs	0		0		0		0
Total operating expenses	222.6		213.3		474.7		411.2
Operating income/(loss)	137.4		103.5		237.0		179.1
Assets	1,931.1		1,875.9		1,931.1		1,875.9
Long-lived assets	707.9	[6]	691.1	[6]	707.9	[6]	691.1	[6]
Capital expenditure on long-lived assets	18.3	[6]	27.4	[6]	26.3	[6]	63.8	[6]
Regenerative Medicine
Segment reporting, operating income/(loss)
Product sales	52.4		2.0		101.2		2.0
Royalties	0		0		0		0
Other revenues	0		0		0		0
Total revenues	52.4		2.0		101.2		2.0
Cost of product sales	17.0	[2]	0.3	[3]	27.0	[4]	0.3	[5]
Research and development	4.3	[2]	0.1	[3]	7.3	[4]	0.1	[5]
Selling, general and administrative ("SG&A")	42.6	[2]	0.7	[3]	84.2	[4]	0.7	[5]
(Gain)/loss on sale of product rights	0		0		0		0
Reorganization costs			0		0		0
Integration and acquisition costs	4.3		6.9		8.0		6.9
Total operating expenses	68.2		8.0		126.5		8.0
Operating income/(loss)	(15.8)		(6.0)		(25.3)		(6.0)
Assets	980.5		1,041.4		980.5		1,041.4
Long-lived assets	25.0	[6]	16.8	[6]	25.0	[6]	16.8	[6]
Capital expenditure on long-lived assets	0.1	[6]	0	[6]	0.1	[6]	0	[6]
All Other Segment
Segment reporting, operating income/(loss)
Product sales	0		0		0		0
Royalties	10.9		11.6		24.8		47.7
Other revenues	0		1.3		0		2.7
Total revenues	10.9		12.9		24.8		50.4
Cost of product sales		[2]	0	[3]	0	[4]	0	[5]
Research and development	0	[2]	0	[3]	0	[4]	0	[5]
Selling, general and administrative ("SG&A")	61.0	[2]	53.7	[3]	114.8	[4]	109.9	[5]
(Gain)/loss on sale of product rights	0		0		0		0
Reorganization costs			4.8		0		8.0
Integration and acquisition costs			0		0		0
Total operating expenses	61.0		58.5		114.8		117.9
Operating income/(loss)	(50.1)		(45.6)		(90.0)		(67.5)
Assets	1,594.8		734.4		1,594.8		734.4
Long-lived assets	64.2	[6]	42.9	[6]	64.2	[6]	42.9	[6]
Capital expenditure on long-lived assets	$ 5.8	[6]	$ 5.3	[6]	$ 8.2	[6]	$ 7.9	[6]

[1] Cost of product sales includes amortization of intangible assets relating to favorable manufacturing contracts of $0.5 million for the three months to June 30, 2012 (2011: $0.4 million) and $0.7 million for the six months to June 30, 2012 (2011: $0.9 million). Research and development costs includes intangible asset impairment charges of $27.0 million for the three and six months to June 30, 2012 (2011: $nil). SG&A costs includes amortization of intangible assets relating to intellectual property rights acquired of $51.0 million for the three months to June 30, 2012 (2011: $36.7 million) and $96.6 million for the six months to June 30, 2012 (2011: $72.7 million).

[2] (1) Depreciation from manufacturing plants ($7.0 million) and amortization of favorable manufacturing contracts ($0.5 million) is included in Cost of product sales; depreciation of research and development assets ($6.4 million) and impairment of certain IPR&D intangible assets in the SP reporting segment ($27.0 million) is included in Research and development; and all other depreciation and amortization ($65.5 million) is included in Selling, general and administrative.

[3] (1) Depreciation from manufacturing plants ($10.5 million) and amortization of favorable manufacturing contracts ($0.4 million) is included in Cost of product sales; depreciation of research and development assets ($6.1 million) is included in Research and development; and all other depreciation, amortization and impairment charges ($51.8 million) is included in Selling, general and administrative.

[4] (1) Depreciation from manufacturing plants ($14.2 million) and amortization of favorable manufacturing contracts ($0.7 million) is included in Cost of product sales; depreciation of research and development assets ($12.8 million) and impairment of IPR&D intangible assets in the SP reporting segment ($27.0 million) is included in Research and development; and all other depreciation and amortization ($124.7 million) is included in Selling, general and administrative.

[5] (1) Depreciation from manufacturing plants ($18.2 million) and amortization of favorable manufacturing contracts ($0.9 million) is included in Cost of product sales; depreciation of research and development assets ($10.8 million) is included in Research and development; and all other depreciation, amortization and impairment ($102.4 million) is included in Selling, general and administrative.

[6] (2) Long-lived assets comprise all non-current assets (excluding goodwill and other intangible assets, deferred contingent consideration assets, deferred tax assets, investments, income tax receivable and financial instruments).