Fair Value - Change in Fair Value for All Assets and Liabilities Using Unobservable Level 3 Inputs As Determined By Level 3 Inputs (Detail) - Fair Value Measurement at Reporting Date (Level 3) [Member] $ in Thousands	6 Months Ended
	Jun. 30, 2017 USD ($)
Common Stock Warrants [Member]
Fair Value Liabilities Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Issuance of warrants	$ 8,715
Change in fair value	2,326
Long-term portion	11,041
Ending balance	11,041
Contingent Consideration [Member]
Fair Value Liabilities Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Beginning balance	22,800
Issuance of common stock in exchange for contingent consideration	(5,227)
Change in fair value	453
Current portion	6,918
Long-term portion	11,108
Ending balance	$ 18,026