Condensed Balance Sheet Details - Schedule of Property and Equipment, Net (Details) - USD ($) $ in Thousands	Mar. 31, 2022	Dec. 31, 2021
Property Plant And Equipment [Line Items]
Property and equipment, gross	$ 321	$ 321
Less: accumulated depreciation and amortization expense	179	156
Property and Equipment, net	142	165	[1]
Furniture and Equipment
Property Plant And Equipment [Line Items]
Property and equipment, gross	204	204
Leasehold Improvements
Property Plant And Equipment [Line Items]
Property and equipment, gross	67	67
Computer Equipment
Property Plant And Equipment [Line Items]
Property and equipment, gross	$ 50	$ 50

[1] The balance sheet at December 31, 2021 has been derived from the audited financial statements included in Rain Therapeutics Inc.’s Annual Report on Form 10-K filed on March 3, 2022.