Consolidated Statements of Shareholders' Equity - USD ($) $ in Thousands	Total	Common Stock	Retained Earnings (Accumulated Deficit)	Other Comprehensive Loss
BEGINNING BALANCE at Dec. 31, 2016	$ 819,184	$ 521,860	$ 319,291	$ (21,967)
BEGINNING BALANCE (in shares) at Dec. 31, 2016		124,390,000
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net (Loss)	(24,550)		(24,550)
Exercise of stock options	9,673	$ 9,673
Exercise of stock options (in shares)		625,000
Compensation and share issuances related to restricted stock awards	7,736	$ 7,736
Compensation and share issuances related to restricted stock awards (in Shares)		138,000
Stock-based compensation expense - stock options	13,282	$ 13,282
Foreign currency translation gain	6,150			6,150
Stock compensation plan withholdings for employee taxes	(2,079)	$ (2,079)
Stock compensation plan withholdings for employee taxes (in Shares)		(62,000)
Unrealized holding gain on available-for-sale securities	267			267
Akorn AG pension liability adjustment gain	1,582			1,582
ENDING BALANCE at Dec. 31, 2017	831,245	$ 550,472	294,741	(13,968)
ENDING BALANCE (in shares) at Dec. 31, 2017		125,091,000
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net (Loss)	(401,909)		(401,909)
Exercise of stock options	546	$ 546
Exercise of stock options (in shares)		22,000
Employee stock purchase plan expense	2,809	$ 2,809
Employee stock purchase plan expense (in shares)		146,000
Compensation and share issuances related to restricted stock awards	11,673	$ 11,673
Compensation and share issuances related to restricted stock awards (in Shares)		288,000
Stock-based compensation expense - stock options	9,830	$ 9,830
Foreign currency translation gain	(8,001)			(8,001)
Stock compensation plan withholdings for employee taxes	(777)	$ (777)
Stock compensation plan withholdings for employee taxes (in Shares)		(55,000)
Unrealized holding gain on available-for-sale securities	(21)			(21)
Akorn AG pension liability adjustment gain	(1,529)			(1,529)
ENDING BALANCE at Dec. 31, 2018	$ 443,866	$ 574,553	(107,168)	(23,519)
ENDING BALANCE (in shares) at Dec. 31, 2018	125,492,373	125,492,000
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net (Loss)	$ (226,770)
Exercise of stock options	0
Exercise of stock options (in shares)
Employee stock purchase plan expense	1,273	$ 1,273
Employee stock purchase plan expense (in shares)
Compensation and share issuances related to restricted stock awards	14,751	$ 14,751
Compensation and share issuances related to restricted stock awards (in Shares)		751,000
Stock-based compensation expense - stock options	5,257	$ 5,257
Foreign currency translation gain	(667)			(667)
Stock compensation plan withholdings for employee taxes	(313)	$ (313)
Stock compensation plan withholdings for employee taxes (in Shares)		(97,000)
Unrealized holding gain on available-for-sale securities	(5)			(5)
Akorn AG pension liability adjustment gain	(3,100)			(3,100)
ENDING BALANCE at Dec. 31, 2019	$ 234,292	$ 595,521	$ (333,938)	$ (27,291)
ENDING BALANCE (in shares) at Dec. 31, 2019	126,145,832	126,146,000