Business Combinations (Details) - USD ($) $ in Millions						3 Months Ended		9 Months Ended
	Sep. 28, 2015	Jul. 30, 2015	Feb. 21, 2015	Feb. 18, 2015	Dec. 31, 2014	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014	Dec. 31, 2013
Non-current assets:
Goodwill					$ 2,474.9	$ 4,289.6	$ 2,373.7	$ 4,289.6	$ 2,373.7	$ 624.6
Pro Forma Information
Post acquisition unwind of inventory fair value adjustment included in consolidated statement of income								23.0	90.6
Integration and acquisition costs						89.9	$ 37.1	(46.8)	$ 155.8
NPS Pharma
Business Acquisition [Line Items]
Percentage of voting interests acquired			100.00%
Cash consideration paid			$ 5,219.6
Acquisition-date fair value of consideration			5,219.6
Current assets:
Cash and cash equivalents			41.6
Short term investments			67.0
Accounts receivable			33.4
Inventories			89.4
Deferred tax assets			156.3
Other current assets			11.1
Total current assets			398.8
Non-current assets:
Property, plant and equipment			4.8
Goodwill			1,679.4
Total assets			7,076.0
Current liabilities:
Accounts payable and other current liabilities			72.5
Short-term debt			27.4
Non-current liabilities:
Long term debt, less current portion			78.9
Deferred tax liabilities			1,673.1
Other non-current liabilities			4.5
Total liabilities			1,856.4
Fair value of identified assets acquired and liabilities assumed			5,219.6
Pro Forma Information
Post acquisition revenues included in consolidated statement of income						86.7		193.8
Post acquisition pre-tax losses included in consolidated statement of income						47.5		207.4
Post acquisition amortization of intangible assets included in consolidated statement of income						70.9		172.4
Post acquisition unwind of inventory fair value adjustment included in consolidated statement of income						6.7		21.7
Post acquisition integration costs included in consolidated statement of income						16.2		76.9
Integration and acquisition costs						$ 13.6		$ 131.2
NPS Pharma | Currently Marketed Products
Non-current assets:
Other intangible assets, net			$ 4,640.0
NPS Pharma | Currently Marketed Products | GATTEX/REVESTIVE
Pro Forma Information
Estimated useful life of intangible assets			24 years
NPS Pharma | Currently Marketed Products | NATPARA/NATPAR
Pro Forma Information
Estimated useful life of intangible assets			24 years
NPS Pharma | Other intangible assets
Non-current assets:
Other intangible assets, net			$ 353.0
Pro Forma Information
Weighted average amortization period of acquired amortizable intangible assets			4 years
NPS Pharma | Other intangible assets | Minimum
Pro Forma Information
Estimated useful life of intangible assets			4 years
NPS Pharma | Other intangible assets | Maximum
Pro Forma Information
Estimated useful life of intangible assets			5 years
Foresight
Business Acquisition [Line Items]
Percentage of voting interests acquired		100.00%
Cash consideration paid		$ 298.8
Current assets:
Total current assets		3.0
Non-current assets:
Goodwill		112.1
Non-current liabilities:
Total liabilities		116.3
Foresight | IPR&D | SHP640
Non-current assets:
Other intangible assets, net		$ 300.0
Solpharm
Business Acquisition [Line Items]
Percentage of voting interests acquired	100.00%
Cash consideration paid	$ 4.5
Acquisition-date fair value of consideration	5.2
Maximum amount of contingent cash consideration	3.1
Fair value of contingent consideration payable	0.7
Non-current assets:
Goodwill	4.4
Total assets	0.8
Non-current liabilities:
Fair value of identified assets acquired and liabilities assumed	$ 5.2
Meritage
Business Acquisition [Line Items]
Cash consideration paid				$ 74.8
Acquisition-date fair value of consideration				166.9
Maximum amount of contingent cash consideration				175.0
Fair value of contingent consideration payable				92.1
Current assets:
Total current assets				5.5
Non-current assets:
Goodwill				41.1
Non-current liabilities:
Total liabilities				54.7
Fair value of identified assets acquired and liabilities assumed				166.9
Meritage | IPR&D | SHP621
Non-current assets:
Other intangible assets, net				$ 175.0
Viropharma
Business Acquisition [Line Items]
Percentage of voting interests acquired					100.00%
Cash consideration paid					$ 3,997.0
Acquisition-date fair value of consideration					3,997.0
Expected operational synergies that will result from combining the commercial operations of Viropharma with those of Shire					400.0
Current assets:
Cash and cash equivalents					232.6
Short term investments					57.8
Accounts receivable					52.2
Inventories					203.6
Deferred tax assets					100.7
Purchased call option					346.7
Other current assets					50.9
Total current assets					1,044.5
Non-current assets:
Property, plant and equipment					24.7
Goodwill					1,655.5
Other non-current assets					10.4
Total assets					5,370.1
Current liabilities:
Accounts payable and other current liabilities					122.7
Short-term debt					551.4
Non-current liabilities:
Deferred tax liabilities					603.5
Other non-current liabilities					95.5
Total liabilities					1,373.1
Fair value of identified assets acquired and liabilities assumed					$ 3,997.0
Pro Forma Information
Discount rate used in determining fair value of acquired in process research and development, low rate					9.50%
Discount rate used in determining fair value of acquired in process research and development, high rate					10.00%
Viropharma | Currently Marketed Products
Non-current assets:
Other intangible assets, net					$ 2,320.0
Pro Forma Information
Weighted average amortization period of acquired amortizable intangible assets					22 years
Viropharma | Currently Marketed Products | Minimum
Pro Forma Information
Estimated useful life of intangible assets					10 years
Viropharma | Currently Marketed Products | Maximum
Pro Forma Information
Estimated useful life of intangible assets					23 years
Viropharma | IPR&D | MARIBAVIR
Non-current assets:
Other intangible assets, net					$ 315.0