Condensed Consolidated Statements of Comprehensive Loss (Unaudited) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Statement Of Financial Position [Abstract]
Net loss	$ (55,998)	$ (36,719)	$ (145,941)	$ (101,657)
Other comprehensive (loss) income:
Change in unrealized gains and losses on investments	(209)	(726)	(886)	756
Comprehensive loss	(56,207)	(37,445)	(146,827)	(100,901)
Add: Comprehensive loss attributable to noncontrolling interest	95		95
Comprehensive loss attributable to Adaptive Biotechnologies Corporation	$ (56,112)	$ (37,445)	$ (146,732)	$ (100,901)