Postretirement Benefits - Fair Value Measurement for Pension Plan Assets by Major Category and Level of Input (Details) - USD ($) $ in Thousands	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Fair value measurements of pension plan assets:
Total	$ 1,002,049	$ 996,879	$ 829,866
Employee Pension Plan
Fair value measurements of pension plan assets:
Total	1,002,049	996,879
Employee Pension Plan | Level 1 Fair Value
Fair value measurements of pension plan assets:
Total	318,448	383,832
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) (1)
Fair value measurements of pension plan assets:
Total	683,601	613,047
Total equity securities | Employee Pension Plan
Fair value measurements of pension plan assets:
Total	357,343	444,407
Total equity securities | Employee Pension Plan | Level 1 Fair Value
Fair value measurements of pension plan assets:
Total	302,703	372,122
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) (1)
Fair value measurements of pension plan assets:
Total	54,640	72,285
U.S. equity securities | Employee Pension Plan
Fair value measurements of pension plan assets:
Total	214,942	261,400
U.S. equity securities | Employee Pension Plan | Level 1 Fair Value
Fair value measurements of pension plan assets:
Total	204,588	244,979
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) (1)
Fair value measurements of pension plan assets:
Total	10,354	16,421
Non-U.S. equity securities | Employee Pension Plan
Fair value measurements of pension plan assets:
Total	142,401	183,007
Non-U.S. equity securities | Employee Pension Plan | Level 1 Fair Value
Fair value measurements of pension plan assets:
Total	98,115	127,143
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) (1)
Fair value measurements of pension plan assets:
Total	44,286	55,864
Debt securities | Employee Pension Plan
Fair value measurements of pension plan assets:
Total	628,961	540,762
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) (1)
Fair value measurements of pension plan assets:
Total	628,961	540,762
Other | Employee Pension Plan
Fair value measurements of pension plan assets:
Total	15,745	11,710
Other | Employee Pension Plan | Level 1 Fair Value
Fair value measurements of pension plan assets:
Total	15,745	11,710
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) (1)
Fair value measurements of pension plan assets:
Total	$ 0	$ 0