Condensed Consolidated Statements of Operations (unaudited) - USD ($) shares in Thousands, $ in Thousands	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Revenue:
Precision oncology testing	$ 60,246	$ 28,837
Development services	7,264	7,818
Total revenue	67,510	36,655
Costs and operating expenses:
Cost of precision oncology testing	18,191	11,023
Cost of development services	2,315	2,512
Research and development expense	37,016	16,316
Sales and marketing expense	25,115	17,807
General and administrative expense	19,785	12,661
Total costs and operating expenses	102,422	60,319
Loss from operations	(34,912)	(23,664)
Interest income	3,318	2,485
Interest expense	(12)	(293)
Other (expense) income, net	(209)	147
Loss before provision for income taxes	(31,815)	(21,325)
Provision for income taxes	14	26
Net loss	(31,829)	(21,351)
Adjustment of redeemable noncontrolling interest	4,100	(4,700)
Net loss attributable to Guardant Health, Inc. common stockholders	$ (27,729)	$ (26,051)
Net loss per share attributable to common stockholders, basic and diluted (in usd per share)	$ (0.29)	$ (0.30)
Weighted-average shares used in computing net loss per share attributable to common stockholders, basic and diluted (in shares)	94,382	85,935