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

Net Loss Per Share (Details) - shares shares in Thousands	3 Months Ended
Net Loss Per Share (Details) - shares shares in Thousands	Mar. 31, 2017	Mar. 31, 2016
Antidilutive securities excluded from the computation of diluted net loss per share
Antidilutive securities excluded from computation of earnings per share (in shares)	21,819	22,153
Employee stock option
Antidilutive securities excluded from the computation of diluted net loss per share
Antidilutive securities excluded from computation of earnings per share (in shares)	21,756	21,856
Warrant to purchase common stock
Antidilutive securities excluded from the computation of diluted net loss per share
Antidilutive securities excluded from computation of earnings per share (in shares)		200
Purchase plan
Antidilutive securities excluded from the computation of diluted net loss per share
Antidilutive securities excluded from computation of earnings per share (in shares)	63	97