Earnings per Share (Details) - USD ($) $ / shares in Units, shares in Millions, $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2025	Sep. 30, 2024	Sep. 30, 2025	Sep. 30, 2024
Numerator:
Net income (loss) attributable to Coupang stockholders	$ 95	$ 70	$ 234	$ (2)
Denominator:
Weighted-average shares used in computing net income (loss) per share attributable to Class A and Class B common stockholders, basic (in shares)	1,823	1,795	1,816	1,792
Dilutive effect of equity compensation awards (in shares)	41	34	37	0
Weighted-average shares used in computing net income (loss) per share attributable to Class A and Class B common stockholders, diluted (in shares)	1,864	1,829	1,853	1,792
Earnings per share
Earnings per share, basic (in USD per share)	$ 0.05	$ 0.04	$ 0.13	$ 0
Earnings per share, diluted (in USD per share)	$ 0.05	$ 0.04	$ 0.13	$ 0
Anti-dilutive shares	0	0	0	30