Quarterly report pursuant to Section 13 or 15(d)

Selected Balance Sheet Data - Summary of Net Change in Carrying Value of Assets Held in Rabbi Trust and Deferred Compensation Liability (Detail)

v3.20.2
Selected Balance Sheet Data - Summary of Net Change in Carrying Value of Assets Held in Rabbi Trust and Deferred Compensation Liability (Detail) - USD ($)
$ in Thousands
3 Months Ended 9 Months Ended
Sep. 30, 2020
Sep. 30, 2019
Sep. 30, 2020
Sep. 30, 2019
Balance Sheet Related Disclosures [Abstract]        
Increase in the carrying value of the assets held in the rabbi trust $ 434 $ 31 $ 170 $ 959
Increase in the net carrying value of the deferred compensation obligation $ 388 $ 31 $ 88 $ 943