INTANGIBLE ASSETS (Tables)

12 Months Ended

Dec. 31, 2019

Goodwill and Intangible Assets Disclosure [Abstract]

Summary of the gross carrying amounts and net book values of our intangible assets

The gross carrying amounts and net book values of the Company’s intangible assets were as follows (in thousands):

	December 31, 2019											December 31, 2018
Product rights	Remaining Useful Life (In years)	Gross Carrying Amount		Accumulated Amortization			Impairment			Net Book Value		Gross Carrying Amount		Accumulated Amortization			Net Book Value
NUCYNTA	6.0	$	1,019,978	$	(455,192	)	$	(189,790	)	$	374,996	$	1,019,978	$	(360,891	)	$	659,087
CAMBIA	4.0	51,360		(31,027		)	—			20,333		51,360		(25,891		)	25,469
Zipsor	2.2	27,250		(22,044		)	—			5,206		27,250		(19,707		)	7,543
		$	1,098,588	$	(508,263	)	(189,790		)	$	400,535	$	1,098,588	$	(406,489	)	$	692,099

Summary of the future amortization expenses of intangible assets

The Company expects future amortization expense, inclusive of the effect of the sale of the NUCYNTA asset on February 13, 2020, to be as follows (in thousands):

Year Ending December 31,	Estimated Amortization Expense
2020	$	13,400
2021	7,473
2022	5,668
2023	4,925
Thereafter	—
Total	$	31,466