Commitments and Contingencies - Narrative (Details) $ in Thousands														1 Months Ended		2 Months Ended	11 Months Ended	12 Months Ended
	Feb. 15, 2019 claim	Feb. 07, 2019 defendent	Dec. 03, 2018 defendent	Oct. 04, 2018 defendent	Aug. 24, 2018 defendent	Jul. 18, 2018 defendent	Jul. 09, 2018 defendent	Jun. 18, 2018 request	May 30, 2018 defendent	Mar. 27, 2018 defendent	Mar. 15, 2018 company defendent	Aug. 17, 2017 company defendent	Apr. 06, 2017 complaint drug	Jul. 31, 2017 USD ($)	May 31, 2016 USD ($) settlement_demand	Nov. 30, 2018 defendent	Apr. 30, 2015 complaint	Dec. 31, 2018 USD ($)	Dec. 31, 2017 USD ($)	Dec. 31, 2016 USD ($)	Feb. 21, 2019 complaint	Feb. 15, 2017 litigation
Loss Contingencies [Line Items]
Rent expense																		$ 18,000	$ 17,000	$ 14,000
Medicaid reimbursement reserve																		15,000	15,000
Legal settlements gains																		$ 22,300	29,312	$ 11,000
Kashiv BioSciences LLC | Legal Cost Reimbursement | Affiliated Entity
Loss Contingencies [Line Items]
Development contract settlement with related party																			$ 8,000
Opana ER FTC Antitrust Suit
Loss Contingencies [Line Items]
Expected time period for decision on case					100 days
Opana ER Antitrust Litigation
Loss Contingencies [Line Items]
Number of complaints | complaint																	14
Texas State Attorney General Civil Investigative Demand
Loss Contingencies [Line Items]
Number of settlement demands | settlement_demand															2
Damages sought, initial demand aggregate total															$ 36,000
Alleged overpayments															$ 16,200
Generic Digoxin and Doxycycline Antitrust Litigation
Loss Contingencies [Line Items]
Number of generic drugs included in consolidation of civil actions | drug													18
Digoxin And Lidocaine-prilocaine Litigation
Loss Contingencies [Line Items]
Number of complaints | complaint													2
Digoxin And Lidocaine-prilocaine Litigation | Subsequent Event
Loss Contingencies [Line Items]
Number of complaints filed by opt-out plaintiffs | complaint																					2
Digoxin And Lidocaine-prilocaine Litigation | Subsequent Event | End-Payor Plaintiff
Loss Contingencies [Line Items]
Number of state law claims dismissed | claim	7
Digoxin And Lidocaine-prilocaine Litigation | Subsequent Event | Indirect Reseller Plaintiff
Loss Contingencies [Line Items]
Number of state law claims dismissed | claim	6
Opiod Medications Litigation
Loss Contingencies [Line Items]
Number of defendants | defendent			32	45	18	41	55		4	35	51	5				37
Number of healthcare provider defendants | company												3
Number of counties filing a complaint (more than) | company											60
Number of cities filing a complaint | company											12
Number of CID requests | request								11
Opiod Medications Litigation | Subsequent Event
Loss Contingencies [Line Items]
Number of defendants | defendent		20
Teva v. Impax Laboratories, LLC.
Loss Contingencies [Line Items]
Number of litigations | litigation																						2
Buprenorphine and Naloxone Medication Litigation
Loss Contingencies [Line Items]
Legal settlements gains														$ 21,000
Settlement payment received														$ 25,000