XML 69 R57.htm IDEA: XBRL DOCUMENT v3.23.2
Components of Retirement Plan Costs (Detail) - USD ($)
$ in Thousands
 3 Months Ended 6 Months Ended
Jun. 30, 2023
Jun. 30, 2022
Jun. 30, 2023
Jun. 30, 2022
Pension Plan [Member]        
Defined Benefit Plan Disclosure [Line Items]        
Service Cost $ 523 $ 791 $ 1,046 $ 1,582
Interest Cost 1,870 1,371 3,740 2,742
Expected Return on Plan Assets (2,672) (2,720) (5,344) (5,440)
Prior Service Cost Amortization 88 89 177 178
Actuarial Loss Amortization   1,377   2,754
Sub-total (191) 908 (381) 1,816
Amounts Capitalized and Deferred 366 (309) 864 (464)
Net Periodic Benefit Cost Recognized 175 599 483 1,352
Other Postretirement Benefits Plan [Member]        
Defined Benefit Plan Disclosure [Line Items]        
Service Cost 373 722 746 1,444
Interest Cost 725 799 1,450 1,598
Expected Return on Plan Assets (852) (854) (1,704) (1,708)
Prior Service Cost Amortization 199 273 397 546
Actuarial Loss Amortization (366) 255 (732) 510
Sub-total 79 1,195 157 2,390
Amounts Capitalized and Deferred 112 (622) 333 (1,133)
Net Periodic Benefit Cost Recognized 191 573 490 1,257
Supplemental Employee Retirement Plan [Member]        
Defined Benefit Plan Disclosure [Line Items]        
Service Cost 63 68 125 136
Interest Cost 188 118 377 236
Prior Service Cost Amortization 14 14 28 28
Actuarial Loss Amortization   199   399
Sub-total 265 399 530 799
Amounts Capitalized and Deferred (82) (119) (164) (238)
Net Periodic Benefit Cost Recognized $ 183 $ 280 $ 366 $ 561