Business Combination and BELBUCA Acquisition - Summary of Asset Purchase Price and Estimated Values of Assets Acquired and Liabilities Assumed (Detail) - USD ($) $ in Thousands		12 Months Ended
	Jan. 06, 2017	Dec. 31, 2017
Asset purchase price:
Deferred cash consideration to Endo		$ 5,853
Estimated fair value of assets acquired:
Bargain purchase gain		(27,336)
BELBUCA [Member]
Asset purchase price:
Deferred cash consideration to Endo	$ 7,536
Total asset purchase price	7,536
Estimated fair value of assets acquired:
Current BELBUCA® product inventory and work-in process	5,412
BELBUCA®-related manufacturing equipment	432
License and distribution rights intangible assets	45,000
Deferred tax liability	(15,972)
Amount attributable to assets acquired	34,872
Bargain purchase gain	$ (27,336)	$ (27,300)