Summary of Significant Accounting Policies - Accounts Receivable (Details) - USD ($)	Mar. 31, 2021	Dec. 31, 2020
Summary of Significant Accounting Policies
Customer allowance for prompt payment discounts	$ 105,000	$ 171,000

Amount of customer allowances for prompt payment discounts.

No definition available.

Name:	rigl_CustomerAllowanceForPromptPaymentDiscounts
Namespace Prefix:	rigl_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant