XML 86 R74.htm IDEA: XBRL DOCUMENT v3.21.1
Components of Net Periodic Benefit Cost (Detail) - USD ($)
$ in Thousands
 12 Months Ended
Dec. 31, 2020
Dec. 31, 2019
Dec. 31, 2018
Net Periodic Benefit Cost:      
Service cost $ 5 $ 275 $ 568
Interest cost 5 91 126
Projected return on plan assets (29) (77) (78)
Amortization of unrecognized net transition obligation and unrecognized net actuarial gain 37 48 41
Net periodic benefit cost $ 18 $ 337 $ 657