Warrant Transaction Agreements - Walmart Stores, Inc. Transaction Agreement (Details) $ / shares in Units, $ in Thousands				12 Months Ended
	Oct. 30, 2023	Jan. 01, 2019	Jul. 20, 2017 USD ($) installment $ / shares shares	Dec. 31, 2023 USD ($) shares	Dec. 31, 2022 USD ($) shares	Dec. 31, 2021 USD ($)	Dec. 31, 2020 shares	Jul. 31, 2017 shares
Warrant Transaction Agreements
Provision compared for common stock warrants				$ 25,028	$ 38,698	$ 6,142
Warrants issued with the Walmart Stores, Inc transaction agreement
Warrant Transaction Agreements
Shares of common stock that can be purchased from warrants issued (in shares) | shares			55,286,696					55,286,696
Reduction in revenue				$ 5,900	$ 7,100	6,100
Cash payments to be received under agreement			$ 200,000
Warrant shares vested (in shares) | shares				34,917,912	27,643,347
Contract asset				$ 2,400
Number of warrants exercised (in shares) | shares				13,094,217	13,094,217
Warrants issued with the Walmart Stores, Inc transaction agreement | Risk free interest rate
Warrant Transaction Agreements
Warrants and rights outstanding measurement input	0.0473	0.0263
Warrants issued with the Walmart Stores, Inc transaction agreement | Volatility
Warrant Transaction Agreements
Warrants and rights outstanding measurement input	0.7500	0.9500
Warrants issued with the Walmart Stores, Inc transaction agreement | Exercise price
Warrant Transaction Agreements
Warrants and rights outstanding measurement input	0.0628	0.0212
Warrants issued with the Walmart Stores, Inc transaction agreement | Stock price
Warrant Transaction Agreements
Warrants and rights outstanding measurement input	0.0570	0.0124
Tranche one of warrants issued with the Walmart Stores Inc transaction agreement
Warrant Transaction Agreements
Reduction in revenue			$ 10,900
Warrant shares vested (in shares) | shares							5,819,652
Exercise price of warrants (in dollars per share) | $ / shares			$ 2.1231
Tranche two of warrants issued with the Walmart Stores, Inc. Transaction Agreement
Warrant Transaction Agreements
Cash payments to be received under agreement			$ 50,000
Warrant shares vested (in shares) | shares			29,098,260
Number of installments | installment			4
Number of shares per installment | shares			7,274,565
Tranche three of warrants issued with the Walmart Stores, Inc. Transaction Agreement
Warrant Transaction Agreements
Shares of common stock that can be purchased from warrants issued (in shares) | shares			20,368,784
Cash payments to be received under agreement			$ 50,000
Number of installments | installment			8
Number of shares per installment | shares			2,546,098
Exercise price of warrants (in dollars per share) | $ / shares			$ 6.28
Tranche one of warrants issued with the Amazon.com, Inc transaction agreement
Warrant Transaction Agreements
Contract asset				$ 19,400
Walmart | Expected average term
Warrant Transaction Agreements
Expected average term	3 years 8 months 19 days	8 years 6 months 18 days
Walmart | Warrants issued with the Walmart Stores, Inc transaction agreement
Warrant Transaction Agreements
Number of warrants exercised (in shares) | shares				13,094,217	13,094,217
Amazon | Tranche one of warrants issued with the Amazon.com, Inc transaction agreement
Warrant Transaction Agreements
Provision for common stock warrants				$ 400	$ 400	$ 500
Maximum | Warrants issued with the Walmart Stores, Inc transaction agreement
Warrant Transaction Agreements
Cash payments to be received under agreement			$ 600,000
Maximum | Tranche two of warrants issued with the Walmart Stores, Inc. Transaction Agreement
Warrant Transaction Agreements
Cash payments to be received under agreement			200,000
Maximum | Tranche three of warrants issued with the Walmart Stores, Inc. Transaction Agreement
Warrant Transaction Agreements
Cash payments to be received under agreement			$ 400,000