v3.19.3
Recent Accounting Pronouncements - Additional Information (Detail) - USD ($)
3 Months Ended 9 Months Ended
Sep. 30, 2019
Sep. 30, 2019
Jan. 01, 2019
New Accounting Pronouncements Or Change In Accounting Principle [Line Items]      
Initial right-of-use assets $ 7,279,000 $ 7,279,000  
Operating lease, expense $ 387,000 $ 1,078,000  
ASU 2016 02 [Member]      
New Accounting Pronouncements Or Change In Accounting Principle [Line Items]      
Initial right-of-use assets     $ 4,642,000