REVENUE (Tables)

12 Months Ended

Dec. 31, 2018

Revenue from Contract with Customer [Abstract]

Schedule of disaggregated revenue from contracts with customers

The following table summarizes revenue from contracts with customers for the years ended December 31, 2018, 2017 and 2016 (in thousands) into categories that depict how the nature, amount, timing and uncertainty of revenue and cash flows are affected by economic factors:

	December 31,
	2018		2017		2016
Product sales, net:
Gralise	$	58,077	$	77,034	$	88,446
CAMBIA	35,803		31,597		31,273
Zipsor	16,387		16,700		27,539
Total neurology product sales, net	110,267		125,331		147,258
NUCYNTA products	18,944		239,539		281,261
Lazanda	755		15,010		26,547
Total product sales, net	129,966		379,880		455,066
Commercialization agreement:
Commercialization rights and facilitation services, net	100,038		—		—
Revenue from transfer of inventory	55,705		—		—
Royalties and milestone revenue	26,061		844		831
Total revenues	$	311,770	$	380,724	$	455,897

Summary of contract assets and liabilities

The following table presents changes in the Company’s contract assets as of December 31, 2018 (in thousands):

	Balance							Balance
	as of							as of
	December 31, 2017		Additions		Deductions			December 31, 2018
Contract assets:
Contract asset, net - Collegium	$	—	$	55,705	$	(53,289	)	$	2,416
Contract asset - Ironwood	—		5,000		(5,000		)	—
	—		60,705		(58,289		)	2,416