SEGMENT INFORMATION (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended			9 Months Ended
	Sep. 30, 2014	Mar. 31, 2014	Sep. 30, 2013	Sep. 30, 2014 segments	Sep. 30, 2013
Segment Reporting [Abstract]
Number of operating segments				2
Number of reportable segments				2
Segment reporting information
Total revenues	$ 2,056.2		$ 1,541.7	$ 5,983.5	$ 3,705.8
Total segment profit (loss)	276.4		(971.9)	378.1	(988.6)
Restructuring, integration and other costs	(61.7)		(243.1)	(337.4)	(345.7)
In-process research and development impairments and other charges	(19.9)		(124.0)	(40.3)	(128.8)
Acquisition-related costs	(1.6)		(8.6)	(3.7)	(24.4)
Acquisition-related contingent consideration	(4.0)		35.0	(14.8)	33.5
Other income (expense)	232.0		(202.4)	275.7	(208.0)
Operating income (loss)	683.9		(891.5)	1,395.6	(633.0)
Interest income	0.8		2.8	3.8	5.4
Interest expense	(258.4)		(249.3)	(746.1)	(581.4)
Loss on extinguishment of debt	0	(93.7)	(8.2)	(93.7)	(29.6)
Foreign exchange and other	(53.0)		5.1	(63.0)	(3.5)
Gain on investments, net	3.4		0	5.9	5.8
Income (loss) before provision for (recovery of) income taxes	376.7		(1,141.1)	502.5	(1,236.3)
Share-based compensation expense	20.2		16.0	60.6	32.5
Ezogabine Retigabine
Segment reporting information
Impairment charges on intangible assets			551.6
Total Segment
Segment reporting information
Total segment profit (loss)	582.0		(309.1)	1,643.4	170.2
Corporate
Segment reporting information
Total segment profit (loss)	(42.9)		(39.3)	(127.3)	(129.8)
Share-based compensation expense	11.0		16.0	32.1	32.5
Developed Markets
Segment reporting information
Total revenues	1,507.9		1,142.7	4,409.4	2,722.8
Total segment profit (loss)	478.0		(328.6)	1,375.3	106.3
Developed Markets | Ezogabine Retigabine
Segment reporting information
Impairment charges on intangible assets			551.6		551.6
Developed Markets | Acquisitions 2013 and 2014
Segment reporting information
Total revenues	254.2			1,628.6
Developed Markets | Acquisitions 2013 and 2014 | Fair Value Adjustment to Inventory and Identifiable Intangible Assets
Segment reporting information
Total segment profit (loss)	223.9			665.3
Emerging Markets
Segment reporting information
Total revenues	548.3		399.0	1,574.1	983.0
Total segment profit (loss)	104.0		19.5	268.1	63.9
Emerging Markets | Acquisitions 2013 and 2014
Segment reporting information
Total revenues	89.3			556.3
Emerging Markets | Acquisitions 2013 and 2014 | Fair Value Adjustment to Inventory and Identifiable Intangible Assets
Segment reporting information
Total revenues				243.2
Total segment profit (loss)	$ 89.5