Nature of Business (Details) - Assertio - Nucynta Purchase Agreement - Nucynta Products $ in Thousands	Feb. 06, 2020 USD ($)
Aggregate purchase price	$ 375,000
Royalty payment as percentage of annual net sales	14.00%

Represents the royalty payment as percentage of annual net sales.

No definition available.

Name:	coll_CollaborativeArrangementRoyaltyPaymentAsPercentageOfAnnualNetSales
Namespace Prefix:	coll_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration