Condensed Consolidated Statements of Comprehensive Loss - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015
Statement Of Income And Comprehensive Income [Abstract]
Net loss	$ (10,493)	$ (3,185)	$ (20,246)	$ (5,457)
Other comprehensive loss:
Foreign currency translation adjustments, net of tax	(1,408)	0	(1,408)	0
Net Comprehensive loss	(11,901)	(3,185)	(21,654)	(5,457)
Comprehensive loss attributable to noncontrolling interest	23	0	23	0
Comprehensive loss attributable to CareDx, Inc.	$ (11,878)	$ (3,185)	$ (21,631)	$ (5,457)