BUSINESS ACQUISITION (Details)		3 Months Ended		10 Months Ended	12 Months Ended
	Mar. 09, 2015 USD ($)	Sep. 30, 2015 USD ($)	Mar. 31, 2015 USD ($)	Dec. 31, 2015 USD ($)	Dec. 31, 2015 USD ($)	Mar. 31, 2016 USD ($)
Acquired Finite-Lived Intangible Assets [Line Items]
Goodwill				$ 210,166,000	$ 210,166,000	$ 208,382,000
Impax Specialty Pharma
Acquired Finite-Lived Intangible Assets [Line Items]
Goodwill						59,700,000
Impax Generics
Acquired Finite-Lived Intangible Assets [Line Items]
Goodwill						148,700,000
Tower And Lineage
Acquired Finite-Lived Intangible Assets [Line Items]
Business combination, consideration transferred	$ 691,300,000	$ 697,200,000
Business combination, acquisition related costs			$ 12,000,000	$ 10,900,000
Severance costs					$ 2,400,000
Business combination, number of positions eliminated					10
Restructuring reserve (less than)						100,000
Cash acquired from acquisition	41,500,000
Business combination, acquired receivables, fair value	56,900,000
Business combination, acquired receivables, estimated uncollectible	9,000,000
Business combination, provisional information, initial accounting incomplete, adjustment, consideration transferred		$ 5,900,000
Business combination, cash acquired and other working capital adjustments	41,500,000
Goodwill	180,800,000					$ 180,808,000
Severance and retention costs			3,000,000
Tower And Lineage | Fair Value Adjustment to Inventory
Acquired Finite-Lived Intangible Assets [Line Items]
Assets, fair value adjustment			1,000,000
Tower And Lineage | Term Loan
Acquired Finite-Lived Intangible Assets [Line Items]
Line of credit facility, commitment fee amount			2,300,000
Tower And Lineage | Term Loan | Wells Fargo Bank, N.A.
Acquired Finite-Lived Intangible Assets [Line Items]
Long-term debt			435,000,000
Tower And Lineage | Impax Specialty Pharma
Acquired Finite-Lived Intangible Assets [Line Items]
Goodwill	59,700,000
Tower And Lineage | Impax Generics
Acquired Finite-Lived Intangible Assets [Line Items]
Goodwill	$ 121,100,000
General and Administrative Expense | Tower And Lineage
Acquired Finite-Lived Intangible Assets [Line Items]
Business combination, acquisition related costs			$ 5,700,000
Currently marketed product rights
Acquired Finite-Lived Intangible Assets [Line Items]
Fair value inputs, discount rate	15.00%
In-process research and development product rights
Acquired Finite-Lived Intangible Assets [Line Items]
Fair value inputs, discount rate	16.00%