Significant Accounting Policies - Additional Information (Detail)	12 Months Ended
	Dec. 31, 2015 USD ($) Security Segment	Dec. 31, 2014 USD ($)	Dec. 31, 2013 USD ($)
Significant Accounting Policies [Line Items]
Cash equivalents	$ 16,300,000	$ 36,600,000
Marketable securities	7,501,000	0
Realized gain (loss) recognized on sale of marketable securities	0	0
Aggregate fair value of securities in unrealized loss position less than twelve months	$ 5,100,000
Number of securities with a unrealized loss position less than twelve months | Security	6
Aggregate fair value of securities in unrealized loss position greater than twelve months	$ 0
Accounts receivable	4,641,000	2,341,000
Assets measured at level 3 on recurring basis	0
Liabilities measured at level 3 on recurring basis	0
Impairment losses	200,000	7,600,000	$ 100,000
Tax benefits of the stock based compensation expenses recognized	$ 0
Number of operating segments | Segment	1
United Kingdom
Significant Accounting Policies [Line Items]
Net assets located in the United Kingdom	$ 1,000,000	1,000,000
Level 3
Significant Accounting Policies [Line Items]
Lease exit liability, fair value		7,300,000
Fair value of loan payable	10,000,000	21,300,000
Novartis
Significant Accounting Policies [Line Items]
Accounts receivable	3,500,000
Biodesix | N S C L C P O C Trial
Significant Accounting Policies [Line Items]
Accounts receivable	$ 1,100,000	$ 1,800,000
Minimum
Significant Accounting Policies [Line Items]
Marketable securities maturity term	3 months
Maximum
Significant Accounting Policies [Line Items]
Marketable securities maturity term	24 months