Business Combination - Summary of Purchase Consideration (Detail) (ImmuMetrix, Inc. [Member], USD $) In Thousands, unless otherwise specified	0 Months Ended
	Jun. 10, 2014
Business Acquisition [Line Items]
Cash paid upon executing agreement and to be paid upon end of objection period	$ 600
Total estimated purchase consideration	17,155
Series G Preferred Stock [Member]
Business Acquisition [Line Items]
Estimated fair value	13,873
Stock Options [Member] | Series G Preferred Stock [Member]
Business Acquisition [Line Items]
Estimated fair value	369
Contingent Consideration [Member] | Series G Preferred Stock [Member]
Business Acquisition [Line Items]
Estimated fair value	$ 2,313