Postretirement Benefits - Fair Value Measurement for Pension Plan Assets by Major Category and Level of Input (Details) - USD ($) $ in Thousands	Dec. 31, 2025	Dec. 31, 2024	Dec. 31, 2023
Fair value measurements of pension plan assets:
Total	$ 1,091,598	$ 1,002,049	$ 996,879
Employee Pension Plan
Fair value measurements of pension plan assets:
Total	1,091,598	1,002,049
Employee Pension Plan | Level 1 Fair Value
Fair value measurements of pension plan assets:
Total	348,578	318,448
Employee Pension Plan | Level 2 Fair Value
Fair value measurements of pension plan assets:
Total	0	0
Employee Pension Plan | Level 3 Fair Value
Fair value measurements of pension plan assets:
Total	0	0
Employee Pension Plan | Net Asset Value (NAV)
Fair value measurements of pension plan assets:
Total	743,020	683,601
Total equity securities | Employee Pension Plan
Fair value measurements of pension plan assets:
Total	396,075	357,343
Total equity securities | Employee Pension Plan | Level 1 Fair Value
Fair value measurements of pension plan assets:
Total	333,021	302,703
Total equity securities | Employee Pension Plan | Level 2 Fair Value
Fair value measurements of pension plan assets:
Total	0	0
Total equity securities | Employee Pension Plan | Level 3 Fair Value
Fair value measurements of pension plan assets:
Total	0	0
Total equity securities | Employee Pension Plan | Net Asset Value (NAV)
Fair value measurements of pension plan assets:
Total	63,054	54,640
U.S. equity securities | Employee Pension Plan
Fair value measurements of pension plan assets:
Total	235,431	214,942
U.S. equity securities | Employee Pension Plan | Level 1 Fair Value
Fair value measurements of pension plan assets:
Total	224,370	204,588
U.S. equity securities | Employee Pension Plan | Level 2 Fair Value
Fair value measurements of pension plan assets:
Total	0	0
U.S. equity securities | Employee Pension Plan | Level 3 Fair Value
Fair value measurements of pension plan assets:
Total	0	0
U.S. equity securities | Employee Pension Plan | Net Asset Value (NAV)
Fair value measurements of pension plan assets:
Total	11,061	10,354
Non-U.S. equity securities | Employee Pension Plan
Fair value measurements of pension plan assets:
Total	160,644	142,401
Non-U.S. equity securities | Employee Pension Plan | Level 1 Fair Value
Fair value measurements of pension plan assets:
Total	108,651	98,115
Non-U.S. equity securities | Employee Pension Plan | Level 2 Fair Value
Fair value measurements of pension plan assets:
Total	0	0
Non-U.S. equity securities | Employee Pension Plan | Level 3 Fair Value
Fair value measurements of pension plan assets:
Total	0	0
Non-U.S. equity securities | Employee Pension Plan | Net Asset Value (NAV)
Fair value measurements of pension plan assets:
Total	51,993	44,286
Debt securities | Employee Pension Plan
Fair value measurements of pension plan assets:
Total	679,966	628,961
Debt securities | Employee Pension Plan | Level 1 Fair Value
Fair value measurements of pension plan assets:
Total	0	0
Debt securities | Employee Pension Plan | Level 2 Fair Value
Fair value measurements of pension plan assets:
Total	0	0
Debt securities | Employee Pension Plan | Level 3 Fair Value
Fair value measurements of pension plan assets:
Total	0	0
Debt securities | Employee Pension Plan | Net Asset Value (NAV)
Fair value measurements of pension plan assets:
Total	679,966	628,961
Other | Employee Pension Plan
Fair value measurements of pension plan assets:
Total	15,557	15,745
Other | Employee Pension Plan | Level 1 Fair Value
Fair value measurements of pension plan assets:
Total	15,557	15,745
Other | Employee Pension Plan | Level 2 Fair Value
Fair value measurements of pension plan assets:
Total	0	0
Other | Employee Pension Plan | Level 3 Fair Value
Fair value measurements of pension plan assets:
Total	0	0
Other | Employee Pension Plan | Net Asset Value (NAV)
Fair value measurements of pension plan assets:
Total	$ 0	$ 0