Quarterly report pursuant to Section 13 or 15(d)

Related-Party Transactions - Additional Information (Detail)

v3.7.0.1
Related-Party Transactions - Additional Information (Detail) - USD ($)
6 Months Ended 12 Months Ended
Jun. 30, 2017
Dec. 31, 2016
Former Member of Board of Directors [Member]    
Related Party Transaction [Line Items]    
Advisory fee paid to related party $ 30,000 $ 60,000