Quarterly report pursuant to Section 13 or 15(d)

Subsequent Events - Additional Information (Detail)

v3.8.0.1
Subsequent Events - Additional Information (Detail) - USD ($)
$ in Thousands
3 Months Ended
Apr. 11, 2018
Apr. 04, 2018
Mar. 27, 2018
Mar. 31, 2018
Mar. 31, 2017
Subsequent Event [Line Items]          
Discounts and offering expenses     $ 12,700 $ 685 $ 1,054
Farm Credit West          
Subsequent Event [Line Items]          
Interest rate (as percent)       4.02%  
Subsequent event | Farm Credit West          
Subsequent Event [Line Items]          
Proceeds from notes payable $ 1,500        
Interest rate (as percent) 4.99%        
Over-allotment option | Subsequent event          
Subsequent Event [Line Items]          
Sale of common stock sold under sale agreement (in shares)   165,000      
Gross proceeds from issuance of common stock   $ 2,000      
Discounts and offering expenses   $ 1,900