Acquisitions and Divestitures - Assets Acquired and Liabilities Assumed (Details) $ in Millions										3 Months Ended	6 Months Ended	12 Months Ended
	Mar. 01, 2016 USD ($)	Jan. 22, 2016 USD ($)	Dec. 15, 2015 USD ($)	Sep. 15, 2015 USD ($)	Aug. 28, 2015 USD ($)	May 12, 2015 USD ($)	Mar. 30, 2015 USD ($)	Oct. 31, 2014 USD ($)	Dec. 18, 2013 USD ($)	Dec. 31, 2015 USD ($)	Dec. 31, 2015 USD ($) products	Dec. 31, 2016 USD ($) products	Jun. 28, 2014 USD ($)	Jun. 27, 2015 USD ($)
Business Acquisition [Line Items]
Goodwill										$ 5,152.7	$ 5,152.7	$ 4,049.4	$ 3,473.1	$ 4,721.2
Tretinoin Products
Business Acquisition [Line Items]
Purchase price paid		$ 416.4
Contingent consideration		0.0
Total purchase consideration		416.4
Cash and cash equivalents		0.0
Accounts receivable		0.0
Inventories		1.4
Prepaid expenses and other current assets		0.0
Property, plant and equipment		0.0
Goodwill		1.7
Total intangible assets		413.3
Total assets		416.4
Accounts payable		0.0
Accrued liabilities		0.0
Long-term debt		0.0
Net deferred income tax liabilities		0.0
Total liabilities		0.0
Net assets acquired		416.4
Development-Stage Rx Products
Business Acquisition [Line Items]
Purchase price paid	$ 0.0
Contingent consideration	24.9
Total purchase consideration	24.9
Cash and cash equivalents	0.0
Accounts receivable	0.0
Inventories	0.0
Prepaid expenses and other current assets	0.0
Property, plant and equipment	0.0
Goodwill	0.0
Total intangible assets	24.9
Total assets	24.9
Accounts payable	0.0
Accrued liabilities	0.0
Long-term debt	0.0
Net deferred income tax liabilities	0.0
Total liabilities	0.0
Net assets acquired	24.9
All Other
Business Acquisition [Line Items]
Purchase price paid											15.3	17.1	71.0
Contingent consideration										13.9	13.9	26.2	0.8
Total purchase consideration											29.2	43.3	71.8
Cash and cash equivalents										0.0	0.0	3.8	0.0
Investment securities													0.0
Accounts receivable										0.0	0.0	4.9	0.0
Inventories										0.0	0.0	7.1	3.0
Prepaid expenses and other current assets												0.1	0.0
Property, plant and equipment												1.2	0.0
Tysabri® royalty stream - at fair value													0.0
Goodwill										0.0	0.0	0.0	4.6
Total intangible assets										29.2	29.2	32.9	64.2
Other non-current assets													0.0
Total assets										29.2	29.2	50.0	71.8
Accounts payable										0.0	0.0	2.8	0.0
Accrued liabilities										0.0	0.0	0.1	0.0
Long-term debt												3.3
Net deferred income tax liabilities										0.0	0.0	0.5	0.0
Other non-current liabilities													0.0
Total liabilities										0.0	0.0	6.7	0.0
Net assets acquired										29.2	$ 29.2	$ 43.3	71.8
Number of products purchased | products											8	4
Entocort®
Business Acquisition [Line Items]
Purchase price paid			$ 380.2
Contingent consideration			0.0
Total purchase consideration			380.2
Cash and cash equivalents			0.0
Accounts receivable			0.0
Inventories			0.2
Goodwill			0.0
Total intangible assets			380.0
Total assets			380.2
Accounts payable			0.0
Accrued liabilities			0.0
Net deferred income tax liabilities			0.0
Total liabilities			0.0
Net assets acquired			380.2
Naturwohl
Business Acquisition [Line Items]
Purchase price paid				$ 150.4
Contingent consideration				0.0
Total purchase consideration				150.4
Cash and cash equivalents				4.6
Accounts receivable				3.3
Inventories				1.5
Goodwill				61.0
Total intangible assets				111.8
Total assets				182.2
Accounts payable				2.8
Accrued liabilities				1.6
Net deferred income tax liabilities				27.4
Total liabilities				31.8
Net assets acquired				150.4
ScarAway®
Business Acquisition [Line Items]
Purchase price paid					$ 26.7
Contingent consideration					0.0
Total purchase consideration					26.7
Cash and cash equivalents					0.0
Accounts receivable					0.0
Inventories					1.0
Goodwill					3.5
Total intangible assets					22.2
Total assets					26.7
Accounts payable					0.0
Accrued liabilities					0.0
Net deferred income tax liabilities					0.0
Total liabilities					0.0
Net assets acquired					26.7
GSK Products
Business Acquisition [Line Items]
Purchase price paid					223.6
Contingent consideration					0.0
Total purchase consideration					223.6
Cash and cash equivalents					0.0
Accounts receivable					0.0
Inventories					0.0
Goodwill					32.6
Total intangible assets					191.0
Total assets					223.6
Accounts payable					0.0
Accrued liabilities					0.0
Net deferred income tax liabilities					0.0
Total liabilities					0.0
Net assets acquired					223.6
Gelcaps
Business Acquisition [Line Items]
Purchase price paid						$ 37.9
Total purchase consideration						37.9
Cash and cash equivalents						4.6
Accounts receivable						7.3
Inventories						7.2
Prepaid expenses and other current assets						2.1
Property, plant and equipment						6.0
Goodwill						6.0
Total intangible assets						11.0
Other non-current assets						0.4
Total assets						44.6
Accounts payable						3.3
Short-term debt						0.0
Accrued liabilities						1.6
Payroll and related taxes						0.0
Accrued customer programs						0.0
Long-term debt						0.0
Net deferred income tax liabilities						1.4
Other non-current liabilities						0.4
Total liabilities						6.7
Net assets acquired						37.9
Omega Restated
Business Acquisition [Line Items]
Purchase price paid							$ 2,983.2
Total purchase consideration										2,983.2
Cash and cash equivalents										14.7	$ 14.7
Accounts receivable										222.9	222.9
Inventories										277.0	277.0
Prepaid expenses and other current assets										51.2	51.2
Property, plant and equipment										130.8	130.8
Goodwill										1,688.7	1,688.7
Total intangible assets										3,379.0	3,379.0
Other non-current assets										2.4	2.4
Total assets										5,766.7	5,766.7
Accounts payable										225.0	225.0
Short-term debt										112.6	112.6
Accrued liabilities										49.3	49.3
Payroll and related taxes										51.3	51.3
Accrued customer programs										28.9	28.9
Long-term debt										1,471.0	1,471.0
Net deferred income tax liabilities										785.5	785.5
Other non-current liabilities										59.9	59.9
Total liabilities										2,783.5	2,783.5
Net assets acquired										2,983.2	2,983.2
Lumara
Business Acquisition [Line Items]
Purchase price paid								$ 83.0
Total purchase consideration								83.0
Cash and cash equivalents								0.0
Accounts receivable								2.9
Inventories								1.5
Prepaid expenses and other current assets								0.4
Property, plant and equipment								0.1
Goodwill								0.0
Total intangible assets								82.0
Other non-current assets								0.0
Total assets								86.9
Accounts payable								0.0
Short-term debt								0.0
Accrued liabilities								3.9
Payroll and related taxes								0.0
Accrued customer programs								0.0
Long-term debt								0.0
Net deferred income tax liabilities								0.0
Other non-current liabilities								0.0
Total liabilities								3.9
Net assets acquired								83.0
Elan
Business Acquisition [Line Items]
Purchase price paid									$ 9,451.9
Contingent consideration									0.0
Total purchase consideration									9,451.9
Cash and cash equivalents									1,807.3
Investment securities									100.0
Accounts receivable									40.6
Inventories									0.0
Prepaid expenses and other current assets									38.1
Property, plant and equipment									9.2
Tysabri® royalty stream - at fair value									5,800.0
Goodwill									2,332.0
Total intangible assets									0.0
Other non-current assets									93.4
Total assets									10,220.6
Accounts payable									2.0
Accrued liabilities									115.5
Net deferred income tax liabilities									632.4
Other non-current liabilities									18.8
Total liabilities									768.7
Net assets acquired									9,451.9
Trademarks, trade names, and brands | Gelcaps
Business Acquisition [Line Items]
Indefinite-lived intangibles						4.4
Trademarks, trade names, and brands | Omega Restated
Business Acquisition [Line Items]
Indefinite-lived intangibles										2,003.8	2,003.8
Trademarks, trade names, and brands | Lumara
Business Acquisition [Line Items]
Indefinite-lived intangibles								0.0
In-process research and development | Tretinoin Products
Business Acquisition [Line Items]
Indefinite-lived intangibles		0.0
In-process research and development | Development-Stage Rx Products
Business Acquisition [Line Items]
Indefinite-lived intangibles	24.9
In-process research and development | All Other
Business Acquisition [Line Items]
Indefinite-lived intangibles										29.2	29.2	$ 4.9
In-process research and development | Entocort®
Business Acquisition [Line Items]
Indefinite-lived intangibles			0.0
In-process research and development | Naturwohl
Business Acquisition [Line Items]
Indefinite-lived intangibles				0.0
In-process research and development | ScarAway®
Business Acquisition [Line Items]
Indefinite-lived intangibles					0.0
In-process research and development | GSK Products
Business Acquisition [Line Items]
Indefinite-lived intangibles					0.0
Distribution and license agreements, supply agreements | Tretinoin Products
Business Acquisition [Line Items]
Definite-lived intangibles		0.0
Distribution and license agreements, supply agreements | Development-Stage Rx Products
Business Acquisition [Line Items]
Definite-lived intangibles	0.0
Distribution and license agreements, supply agreements | All Other
Business Acquisition [Line Items]
Definite-lived intangibles										0.0	0.0	1.8	17.8
Distribution and license agreements, supply agreements | Entocort®
Business Acquisition [Line Items]
Definite-lived intangibles			0.0
Distribution and license agreements, supply agreements | Naturwohl
Business Acquisition [Line Items]
Definite-lived intangibles				21.4
Distribution and license agreements, supply agreements | ScarAway®
Business Acquisition [Line Items]
Definite-lived intangibles					0.0
Distribution and license agreements, supply agreements | GSK Products
Business Acquisition [Line Items]
Definite-lived intangibles					0.0
Distribution and license agreements, supply agreements | Elan
Business Acquisition [Line Items]
Definite-lived intangibles									0.0
Developed product technology, formulations, and product rights | Tretinoin Products
Business Acquisition [Line Items]
Definite-lived intangibles		411.0
Developed product technology, formulations, and product rights | Development-Stage Rx Products
Business Acquisition [Line Items]
Definite-lived intangibles	0.0
Developed product technology, formulations, and product rights | All Other
Business Acquisition [Line Items]
Definite-lived intangibles										0.0	0.0	18.0
Developed product technology, formulations, and product rights | Entocort®
Business Acquisition [Line Items]
Definite-lived intangibles			380.0
Developed product technology, formulations, and product rights | Naturwohl
Business Acquisition [Line Items]
Definite-lived intangibles				0.0
Developed product technology, formulations, and product rights | ScarAway®
Business Acquisition [Line Items]
Definite-lived intangibles					0.5
Developed product technology, formulations, and product rights | GSK Products
Business Acquisition [Line Items]
Definite-lived intangibles					0.0
Developed product technology, formulations, and product rights | Gelcaps
Business Acquisition [Line Items]
Definite-lived intangibles						0.0
Developed product technology, formulations, and product rights | Omega Restated
Business Acquisition [Line Items]
Definite-lived intangibles										31.4	31.4
Developed product technology, formulations, and product rights | Lumara
Business Acquisition [Line Items]
Definite-lived intangibles								82.0
Customer relationships and distribution networks | Tretinoin Products
Business Acquisition [Line Items]
Definite-lived intangibles		0.0
Customer relationships and distribution networks | Development-Stage Rx Products
Business Acquisition [Line Items]
Definite-lived intangibles	0.0
Customer relationships and distribution networks | All Other
Business Acquisition [Line Items]
Definite-lived intangibles										0.0	0.0	8.2	9.8
Customer relationships and distribution networks | Entocort®
Business Acquisition [Line Items]
Definite-lived intangibles			0.0
Customer relationships and distribution networks | Naturwohl
Business Acquisition [Line Items]
Definite-lived intangibles				25.9
Customer relationships and distribution networks | ScarAway®
Business Acquisition [Line Items]
Definite-lived intangibles					9.8
Customer relationships and distribution networks | GSK Products
Business Acquisition [Line Items]
Definite-lived intangibles					61.5
Customer relationships and distribution networks | Gelcaps
Business Acquisition [Line Items]
Definite-lived intangibles						6.6
Customer relationships and distribution networks | Omega Restated
Business Acquisition [Line Items]
Definite-lived intangibles										1,056.3	1,056.3
Customer relationships and distribution networks | Lumara
Business Acquisition [Line Items]
Definite-lived intangibles								0.0
Customer relationships and distribution networks | Elan
Business Acquisition [Line Items]
Definite-lived intangibles									0.0
Trademarks, trade names, and brands | All Other
Business Acquisition [Line Items]
Definite-lived intangibles										0.0	0.0		34.8
Trademarks, trade names, and brands | Entocort®
Business Acquisition [Line Items]
Definite-lived intangibles			0.0
Trademarks, trade names, and brands | Naturwohl
Business Acquisition [Line Items]
Definite-lived intangibles				64.2
Trademarks, trade names, and brands | ScarAway®
Business Acquisition [Line Items]
Definite-lived intangibles					11.4
Trademarks, trade names, and brands | GSK Products
Business Acquisition [Line Items]
Definite-lived intangibles					129.5
Trademarks, trade names, and brands | Gelcaps
Business Acquisition [Line Items]
Definite-lived intangibles						$ 0.0
Trademarks, trade names, and brands | Omega Restated
Business Acquisition [Line Items]
Definite-lived intangibles										287.5	287.5
Trademarks, trade names, and brands | Lumara
Business Acquisition [Line Items]
Definite-lived intangibles								$ 0.0
Trademarks, trade names, and brands | Elan
Business Acquisition [Line Items]
Definite-lived intangibles									0.0
Non-compete agreements | Tretinoin Products
Business Acquisition [Line Items]
Definite-lived intangibles		$ 2.3
Non-compete agreements | Development-Stage Rx Products
Business Acquisition [Line Items]
Definite-lived intangibles	$ 0.0
Non-compete agreements | All Other
Business Acquisition [Line Items]
Definite-lived intangibles										$ 0.0	$ 0.0	$ 0.0	$ 1.8
Non-compete agreements | Entocort®
Business Acquisition [Line Items]
Definite-lived intangibles			$ 0.0
Non-compete agreements | Naturwohl
Business Acquisition [Line Items]
Definite-lived intangibles				$ 0.3
Non-compete agreements | ScarAway®
Business Acquisition [Line Items]
Definite-lived intangibles					0.5
Non-compete agreements | GSK Products
Business Acquisition [Line Items]
Definite-lived intangibles					$ 0.0
Non-compete agreements | Elan
Business Acquisition [Line Items]
Definite-lived intangibles									$ 0.0