Rigel Pharmaceuticals, Inc. Quarterly report pursuant to Section 13 or 15(d)

Net Loss Per Share (Details) - shares shares in Thousands	3 Months Ended		9 Months Ended
Net Loss Per Share (Details) - shares shares in Thousands	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Antidilutive securities excluded from the computation of diluted net loss per share
Total	21,153	20,790	21,153	20,790
Employee stock option
Antidilutive securities excluded from the computation of diluted net loss per share
Total	21,044	20,721	21,044	20,721
Purchase Plan
Antidilutive securities excluded from the computation of diluted net loss per share
Total	109	69	109	69