Business Combinations, Dispositions and Other Strategic Investments (Details) $ / shares in Units, shares in Millions, SFr in Millions														1 Months Ended	3 Months Ended												6 Months Ended			9 Months Ended			12 Months Ended
	Jan. 02, 2015 USD ($)	Oct. 02, 2014 USD ($)	Aug. 12, 2014 USD ($)	Jul. 22, 2014 CHF (SFr)	Jun. 27, 2014 USD ($)	Apr. 17, 2014 USD ($) item $ / shares	Apr. 17, 2014 USD ($) item $ / shares	Apr. 02, 2014 USD ($)	Apr. 01, 2014 USD ($)	Jan. 02, 2014 USD ($) item	Nov. 15, 2013 USD ($) product	Sep. 30, 2011 USD ($)	Aug. 01, 2011 USD ($)	Jun. 30, 2015 USD ($)	Dec. 31, 2015 USD ($)	Sep. 30, 2015 USD ($)	Jun. 30, 2015 USD ($)	Mar. 31, 2015 USD ($)	Dec. 31, 2014 USD ($)	Sep. 30, 2014 USD ($)	Jun. 30, 2014 USD ($)	Mar. 31, 2014 USD ($)	Dec. 31, 2013 USD ($)	Sep. 30, 2013 USD ($)	Jun. 30, 2013 USD ($)	Mar. 31, 2013 USD ($)	Jun. 30, 2015 USD ($)	Jun. 30, 2014 USD ($)	Jun. 30, 2013 USD ($)	Sep. 30, 2015 USD ($)	Sep. 30, 2014 USD ($)	Sep. 30, 2013 USD ($)	Dec. 31, 2015 USD ($) shares	Dec. 31, 2014 USD ($) shares	Dec. 31, 2013 USD ($)	Oct. 22, 2014 shares	Jun. 20, 2014 USD ($)	Aug. 27, 2013 $ / shares
Business Acquisition [Line Items]
Acquisition-related costs															$ 129,000	$ 230,000	$ 225,000	$ 1,257,000	$ 3,287,000	$ 8,159,000	$ 20,940,000	$ 454,000	$ 934,000	$ 1,459,000		$ 519,000	$ 1,482,000	$ 21,394,000	$ 519,000	$ 1,712,000	$ 29,553,000	$ 1,978,000	$ 1,841,000	$ 32,840,000	$ 2,912,000
Bargain purchase gain																		849,000					3,707,000				849,000			849,000			849,000		3,707,000
Revenue, Net															279,977,000	256,801,000	220,920,000	227,378,000	202,856,000	127,698,000	$ 133,872,000	$ 90,622,000	$ 84,953,000	$ 81,892,000	$ 77,012,000	$ 73,854,000	448,298,000	$ 224,494,000	$ 150,866,000	705,099,000	352,192,000	$ 232,758,000	985,076,000	555,048,000	317,711,000
Number of products dispositioned | item						1	1
Gain (Loss) on Disposition of Business																																		8,500,000
Business Acquisition Percentage Not Exceeded Of Voting Interests Acquired					20.00%
Available-for-sale Securities															5,900,000																		5,900,000
Available-for-sale Securities, Current														$ 5,632,000	5,941,000	$ 5,637,000	$ 5,632,000	$ 5,558,000	7,268,000	$ 10,804,000							$ 5,632,000			$ 5,637,000	$ 10,804,000		5,941,000	7,268,000
ECR Pharmaceuticals Divestiture [Member]
Business Acquisition [Line Items]
Gain (Loss) on Disposition of Business																																		900,000
Disposal Group, Including Discontinued Operation, Consideration																			$ 41,000,000															41,000,000			$ 41,000,000
Income (Loss) from Discontinued Operations, Net of Tax, Including Portion Attributable to Noncontrolling Interest								$ 500,000
Excelvision [Member]
Business Acquisition [Line Items]
Business Combination, Consideration Transferred	$ 28,400,000			SFr 21.7
Acquisition-related costs																																	200,000	300,000
Payments to Acquire Businesses, Gross	25,900,000
Business Combination, Contingent Consideration, Liability	2,500,000
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Cash and Equivalents	1,200,000
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Current Assets, Receivables	3,400,000
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Inventory	4,200,000
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Current Assets, Other	900,000
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Property, Plant, and Equipment	26,600,000
Total fair value of acquired assets	36,300,000
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Current Liabilities	1,700,000
Assumed non-current liabilities	(3,900,000)
Deferred tax liabilities	(1,400,000)
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Liabilities, Total	7,000,000
Business Combination, Recognized Identifiable Assets Acquired And Liabilities Assumed, Bargain Purchase Gain Adjustment To Net Assets And Liabilities	(900,000)
Business Combination, Recognized Identifiable Assets Acquired, Goodwill, and Liabilities Assumed, Net, Total	28,400,000
Bargain purchase gain																																	900,000
Business Combination, Pro Forma Information, Revenue of Acquiree since Acquisition Date, Actual																																	$ 27,500,000
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Deferred Tax Liabilities Noncurrent	1,400,000
Lloyd Animal Health Products [Member]
Business Acquisition [Line Items]
Business Combination, Consideration Transferred		$ 18,000,000
Payments to Acquire Businesses, Gross		16,100,000
Business Combination, Contingent Consideration, Liability		2,000,000
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Current Assets, Receivables		100,000
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Inventory		2,500,000
Business Combination, Recognized Identifiable Assets Acquired, Goodwill, and Liabilities Assumed, Net, Total		$ 18,000,000
Acquired Finite-lived Intangible Assets, Weighted Average Useful Life																																	10 years 8 months 12 days
VersaPharm [Member]
Business Acquisition [Line Items]
Acquisition-related costs			$ 7,000,000																														$ 500,000	8,100,000
Payments to Acquire Businesses, Gross			433,000,000
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Cash and Equivalents			100,000
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Current Assets, Receivables			3,100,000
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Inventory			21,000,000
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Current Assets, Other			2,800,000
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Property, Plant, and Equipment			1,500,000
Total fair value of acquired assets			597,800,000
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Current Liabilities			12,200,000
Assumed non-current liabilities			(81,800,000)
Deferred tax liabilities			(153,200,000)
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Liabilities, Total			247,200,000
Business Combination, Recognized Identifiable Assets Acquired, Goodwill, and Liabilities Assumed, Net, Total			350,600,000
Business Combination, Pro Forma Information, Revenue of Acquiree since Acquisition Date, Actual																																	$ 63,900,000	24,500,000
Acquired Finite-lived Intangible Assets, Weighted Average Useful Life																																	11 years 4 months 24 days
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Deferred Tax Liabilities Noncurrent			$ 153,200,000
Hi-Tech Pharmacal Co., Inc [Member]
Business Acquisition [Line Items]
Business Combination, Consideration Transferred						$ 649,600,000
Acquisition-related costs																																	$ 800,000	21,300,000	1,600,000
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Cash and Equivalents						89,700,000	$ 89,700,000
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Current Assets, Receivables						48,600,000	48,600,000
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Inventory						52,400,000	52,400,000
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Current Assets, Other						34,000,000	34,000,000
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Property, Plant, and Equipment						45,200,000	45,200,000
Total fair value of acquired assets						796,600,000	796,600,000
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Current Liabilities						22,600,000	22,600,000
Assumed non-current liabilities						(3,300,000)	(3,300,000)
Deferred tax liabilities						(121,100,000)	(121,100,000)
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Liabilities, Total						147,000,000	147,000,000
Business Combination, Recognized Identifiable Assets Acquired, Goodwill, and Liabilities Assumed, Net, Total						649,600,000	649,600,000
Business Combination, Pro Forma Information, Revenue of Acquiree since Acquisition Date, Actual																																	$ 324,500,000	150,700,000
Debt Instrument, Face Amount						$ 600,000,000	$ 600,000,000
Business Acquisition, Share Price (in Dollars per share) | $ / shares						$ 43.50	$ 43.50
Common Stock, Par or Stated Value Per Share (in Dollars per share) | $ / shares																																						$ 0.01
Business Acquisition, Percentage of Voting Interests Acquired						50.00%	50.00%
Acquired Finite-lived Intangible Assets, Weighted Average Useful Life																																	15 years 7 months 6 days
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Deferred Tax Liabilities Noncurrent						$ 121,100,000	$ 121,100,000
Betimol Acquisition [Member]
Business Acquisition [Line Items]
Business Combination, Consideration Transferred	11,500,000
Payments to Acquire Businesses, Gross	7,500,000									$ 7,500,000				$ 4,700,000
Business Combination, Contingent Consideration, Liability															4,700,000																		$ 4,700,000
Acquired Finite-lived Intangible Assets, Weighted Average Useful Life																																	15 years
Business Acquisition, Consideration, Sales Multiplier | item										1.5
Business Combination, Contingent Consideration Arrangements, Range of Outcomes, Value, High										$ 2,000,000
Business Combination, Contingent Consideration Arrangements, Triggering Sales Amount										$ 14,000,000
Business Combination, Contingent Consideration Arrangements, Triggering Duration										1 year
Business Combination, Contingent Consideration Arrangements, Triggering Duration Span										5 years
Business Combination, Contingent Consideration Arrangements, Range of Outcomes, Value, Low										$ 0
Business Combination, Contingent Consideration Arrangements, Change in Amount of Contingent Consideration, Liability																																	$ 200,000
Merck Acquisition [Member]
Business Acquisition [Line Items]
Business Combination, Consideration Transferred	52,800,000										$ 52,800,000
Total fair value of acquired assets	56,500,000
Bargain purchase gain	$ 3,700,000
Business Combination, Number of Products | product											2
Finite-lived Intangible Assets, Amortization Period for Tax Purposes																																	15 years
Merck Acquisition [Member] | Inspire Pharmaceuticals [Member]
Business Acquisition [Line Items]
Business Combination, Number of Products | product											3
Kilitch Drugs Limited [Member]
Business Acquisition [Line Items]
Product Licensing Rights																																	$ 3,800,000	$ 2,800,000	2,700,000
Aciex Agreement [Member]
Business Acquisition [Line Items]
Business Combination, Consideration Transferred					$ 10,800,000
Payments to Acquire Additional Interest in Subsidiaries												$ 2,000,000	$ 8,000,000
Shares Received on Disposition of Assets (in Shares) | shares																																				4.3
Shares Sold (in Shares) | shares																																	1.1	0.2
Shares Sold Value																																	$ 2,600,000	$ 600,000
Gain Loss On Sale Of Shares																																	200,000
Available-for-sale Securities, Gross Unrealized Gain (Loss)																																	1,600,000
Available-for-sale Securities															5,900,000																		5,900,000
Available-for-sale Securities, Current															5,900,000																		$ 5,900,000
Convertible Debt [Member] | Aciex Agreement [Member]
Business Acquisition [Line Items]
Payments for (Proceeds from) Other Investing Activities					$ 400,000		$ 400,000
Trademarks [Member] | VersaPharm [Member]
Business Acquisition [Line Items]
Acquired Finite-lived Intangible Assets, Weighted Average Useful Life																																	3 years
Trademarks [Member] | Hi-Tech Pharmacal Co., Inc [Member]
Business Acquisition [Line Items]
Acquired Finite-lived Intangible Assets, Weighted Average Useful Life																																	9 years
Customer Relationships [Member] | Hi-Tech Pharmacal Co., Inc [Member]
Business Acquisition [Line Items]
Acquired Finite-lived Intangible Assets, Weighted Average Useful Life																																	1 year
Before Discount [Member] | Betimol Acquisition [Member]
Business Acquisition [Line Items]
Business Combination, Contingent Consideration, Liability															4,500,000																		$ 4,500,000
After Discount [Member] | Betimol Acquisition [Member]
Business Acquisition [Line Items]
Business Combination, Contingent Consideration, Liability															$ 4,000,000																		$ 4,000,000
Marketed Under Abbreviated New Drug Applications [Member] | Watson Laboratories, Inc. [Member]
Business Acquisition [Line Items]
Number of products dispositioned | item						3	3
Marketed Under a New Drug Application [Member] | Watson Laboratories, Inc. [Member]
Business Acquisition [Line Items]
Number of products dispositioned | item						1	1
Lidocaine/Prilocaine Topical Cream [Member] | Watson Laboratories, Inc. [Member]
Business Acquisition [Line Items]
Disposal Group, Including Discontinued Operation, Revenue																																		$ 1,500,000	$ 6,800,000
Zioptan [Member]
Business Acquisition [Line Items]
Acquired Finite-lived Intangible Assets, Weighted Average Useful Life									10 years
Zioptan [Member] | Licensing Agreements [Member]
Business Acquisition [Line Items]
Business Combination, Consideration Transferred									$ 11,200,000
Other Nonoperating Income (Expense) [Member] | Watson Product Disposition [Member]
Business Acquisition [Line Items]
Gain (Loss) on Disposition of Business							$ 16,800,000