NET LOSS PER SHARE - Basic and Diluted Earnings Per Share (Details) - USD ($) $ / shares in Units, shares in Millions, $ in Millions	3 Months Ended						9 Months Ended
	Sep. 30, 2021	Jun. 30, 2021	Mar. 31, 2021	Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2020	Sep. 30, 2021	Sep. 30, 2020
Numerator
Net loss attributable to Rivian	$ (1,233)	$ (580)	$ (414)	$ (288)	$ (200)	$ (177)	$ (2,227)	$ (665)
Net loss attributable to common stockholders	$ (1,233)			$ (288)			$ (2,227)	$ (665)
Denominator
Weighted average common shares outstanding - basic (in shares)	101			100			101	100
Effect of dilutive securities - warrants, nonvested RSUs, stock options, convertible notes (in shares)	0			0			0	0
Weighted average common shares outstanding - diluted (in shares)	101			100			101	100
Basic net loss per share (in USD per share)	$ (12.21)			$ (2.88)			$ (22.05)	$ (6.65)
Diluted net loss per share (in USD per share)	$ (12.21)			$ (2.88)			$ (22.05)	$ (6.65)