Annual report pursuant to Section 13 and 15(d)

Soft Dollar Arrangements - Additional Information (Detail)

v3.10.0.1
Soft Dollar Arrangements - Additional Information (Detail) - USD ($)
$ in Thousands
12 Months Ended
Dec. 31, 2018
Dec. 31, 2017
Dec. 31, 2016
Soft Dollar Arrangements [Abstract]      
Soft dollar credits $ 772 $ 859 $ 804