Condensed Consolidated Statements of Operations and Comprehensive Loss - USD ($)	3 Months Ended		9 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2023	Dec. 31, 2022
Income Statement [Abstract]
Revenue (includes related party revenue of nil and $13,068 for the three months ended December 31, 2023 and 2022, respectively, and $11,753 and $36,258 for the nine months ended December 31, 2023 and 2022, respectively)	$ 44,747,000	$ 66,940,000	$ 155,610,000	$ 207,112,000
Cost of revenue (includes related party cost of nil and $231 for the three months ended December 31, 2023 and 2022, respectively, and $295 and $(279) for the nine months ended December 31, 2023 and 2022, respectively)	24,811,000	36,189,000	83,265,000	112,598,000
Gross profit	19,936,000	30,751,000	72,345,000	94,514,000
Operating expenses:
Research and development (includes related party expenses of $2,781 and $3,251 for the three months ended December 31, 2023 and 2022, respectively, and $10,989 and $9,517 for the nine months ended December 31, 2023 and 2022, respectively)	41,720,000	57,270,000	158,637,000	161,877,000
Sales and marketing	27,683,000	39,879,000	68,669,000	98,148,000
General and administrative	31,446,000	30,702,000	107,476,000	89,226,000
Restructuring and other charges	1,497,000	0	8,368,000	0
Goodwill impairment	198,800,000	0	198,800,000	0
Total operating expenses	301,146,000	127,851,000	541,950,000	349,251,000
Loss from operations	(281,210,000)	(97,100,000)	(469,605,000)	(254,737,000)
Other income (expense):
Interest income, net	3,230,000	3,671,000	11,289,000	5,307,000
Other income (expense), net	23,000	855,000	501,000	(267,000)
Loss before income taxes	(277,957,000)	(92,574,000)	(457,815,000)	(249,697,000)
Provision for (benefit from) income taxes	19,000	(613,000)	55,000	(2,139,000)
Net loss	(277,976,000)	(91,961,000)	(457,870,000)	(247,558,000)
Other comprehensive income (loss), net of tax	0	(1,943,000)	620,000	(490,000)
Total comprehensive loss	$ (277,976,000)	$ (93,904,000)	$ (457,250,000)	$ (248,048,000)
Net loss per share of Class A and Class B common stock attributable to common stockholders:
Net loss per share attributable to common stockholders, basic (usd per share)	$ (0.58)	$ (0.20)	$ (0.97)	$ (0.55)
Net loss per share attributable to common stockholders, diluted (usd per share)	$ (0.58)	$ (0.20)	$ (0.97)	$ (0.55)
Weighted-average shares used to compute net loss per share:
Weighted-average shares used in computing net loss per share attributable to common stockholders, basic (shares)	480,809,546	453,407,202	472,683,220	449,949,829
Weighted-average shares used in computing net loss per share attributable to common stockholders, diluted (shares)	480,809,546	453,407,202	472,683,220	449,949,829