Annual report pursuant to Section 13 and 15(d)

Income Tax - Reconciliation of Unrecognized Tax Benefits of Uncertain Tax Positions (Detail)

v3.19.1
Income Tax - Reconciliation of Unrecognized Tax Benefits of Uncertain Tax Positions (Detail) - USD ($)
$ in Thousands
12 Months Ended
Dec. 31, 2018
Dec. 31, 2017
Dec. 31, 2016
Income Tax Disclosure [Abstract]      
Unrecognized tax benefits, Beginning Balance $ 715 $ 715 $ 699
Additions based on tax positions related to the current year 6 0 16
Deductions based on tax positions related to prior years (4) 0 0
Unrecognized tax benefits, Ending Balance $ 717 $ 715 $ 715