Business Combinations (ViroPharrma,NPS Pharma, Meritage) (Details) - USD ($) $ in Millions				3 Months Ended		6 Months Ended
	Feb. 21, 2015	Feb. 18, 2015	Dec. 31, 2014	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014	Dec. 31, 2013
Non-current assets:
Goodwill			$ 2,474.9	$ 4,173.2	$ 2,283.4	$ 4,173.2	$ 2,283.4	$ 624.6
Pro Forma Information
Post acquisition unwind of inventory fair value adjustment included in consolidated statement of income						16.3	72.5
Integration and acquisition costs				(212.4)	$ 112.1	(136.7)	$ 118.7
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				80.9		107.1
Post acquisition pre-tax losses included in consolidated statement of income				108.7		159.9
Post acquisition amortization of intangible assets included in consolidated statement of income				71.4		101.5
Post acquisition unwind of inventory fair value adjustment included in consolidated statement of income				5.2		15.1
Post acquisition integration costs included in consolidated statement of income				43.3		60.7
Integration and acquisition costs				$ 47.8		$ 117.7
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 | Royalty rights
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 | Royalty rights | Minimum
Pro Forma Information
Estimated useful life of intangible assets	4 years
NPS Pharma | Royalty rights | Maximum
Pro Forma Information
Estimated useful life of intangible assets	5 years
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
Non-current assets:
Other intangible assets, net			$ 315.0
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 | OBS
Non-current assets:
Other intangible assets, net		$ 175.0