Employee Benefit Plans - Summary of Weighted-Average Assumptions for Disclosure (Detail) - Supplemental Employee Retirement Plan [Member] |
12 Months Ended | |
---|---|---|
Dec. 31, 2019 |
Dec. 31, 2018 |
|
Weighted-average assumptions for Disclosure | ||
Discount rate | 2.95% | 4.00% |
Mortality table | Pri-2012 | |
mortality improvement scale | MP-2019 |