Pensions and Other Postretirement Plans (Fair Value of Pension Plan Assets) (Details 9) - USD ($) $ in Thousands		Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Pension Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value		$ 3,005,687	$ 2,528,344	$ 3,394,823
Pension Plan [Member] | Fair Value, Recurring [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value		3,005,687	2,528,344
Total investments [Member] | Pension Plan [Member] | Fair Value, Recurring [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value		2,210,220	1,780,461
Cash Equivalents [Member] | Pension Plan [Member] | Fair Value, Recurring [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value		2,230	1,980
U.S. equities [Member] | Pension Plan [Member] | Fair Value, Recurring [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value	[1]	1,793,705	1,507,609
International equities [Member] | Pension Plan [Member] | Fair Value, Recurring [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value	[2]	$ 414,285	$ 270,872
Short-term investment funds [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Plan Assets, Fair Value by Hierarchy and NAV [Extensible Enumeration]		Fair Value Measured at Net Asset Value Per Share [Member]	Fair Value Measured at Net Asset Value Per Share [Member]
Short-term investment funds [Member] | Pension Plan [Member] | Fair Value, Recurring [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value	[3]	$ 197,712	$ 170,062
Private investment fund [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Plan Assets, Fair Value by Hierarchy and NAV [Extensible Enumeration]		Fair Value Measured at Net Asset Value Per Share [Member]	Fair Value Measured at Net Asset Value Per Share [Member]
Private investment fund [Member] | Pension Plan [Member] | Fair Value, Recurring [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value	[4]	$ 509,647	$ 406,600
U.S. stock index fund [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Plan Assets, Fair Value by Hierarchy and NAV [Extensible Enumeration]		Fair Value Measured at Net Asset Value Per Share [Member]	Fair Value Measured at Net Asset Value Per Share [Member]
U.S. stock index fund [Member] | Pension Plan [Member] | Fair Value, Recurring [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value	[5]	$ 84,767	$ 168,532
Receivables for settlement of investments purchased, net [Member] | Pension Plan [Member] | Fair Value, Recurring [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value		3,341	2,689
Level 1 [Member] | Total investments [Member] | Pension Plan [Member] | Fair Value, Recurring [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value		2,210,220	1,780,461
Level 1 [Member] | Cash Equivalents [Member] | Pension Plan [Member] | Fair Value, Recurring [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value		2,230	1,980
Level 1 [Member] | U.S. equities [Member] | Pension Plan [Member] | Fair Value, Recurring [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value	[1]	1,793,705	1,507,609
Level 1 [Member] | International equities [Member] | Pension Plan [Member] | Fair Value, Recurring [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value	[2]	414,285	270,872
Level 2 [Member] | Total investments [Member] | Pension Plan [Member] | Fair Value, Recurring [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value		0	0
Level 2 [Member] | Cash Equivalents [Member] | Pension Plan [Member] | Fair Value, Recurring [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value		0	0
Level 2 [Member] | U.S. equities [Member] | Pension Plan [Member] | Fair Value, Recurring [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value	[1]	0	0
Level 2 [Member] | International equities [Member] | Pension Plan [Member] | Fair Value, Recurring [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value	[2]	0	0
Level 3 [Member] | Total investments [Member] | Pension Plan [Member] | Fair Value, Recurring [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value		0	0
Level 3 [Member] | Cash Equivalents [Member] | Pension Plan [Member] | Fair Value, Recurring [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value		0	0
Level 3 [Member] | U.S. equities [Member] | Pension Plan [Member] | Fair Value, Recurring [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value	[1]	0	0
Level 3 [Member] | International equities [Member] | Pension Plan [Member] | Fair Value, Recurring [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value	[2]	0	0
Fair Value Measured at Net Asset Value Per Share [Member] | Short-term investment funds [Member] | Pension Plan [Member] | Fair Value, Recurring [Member]
Defined Benefit Plan Disclosure [Line Items]
Unfunded Commitment		0	0
Fair Value Measured at Net Asset Value Per Share [Member] | Private investment fund [Member] | Pension Plan [Member] | Fair Value, Recurring [Member]
Defined Benefit Plan Disclosure [Line Items]
Unfunded Commitment		16,515	20,673
Fair Value Measured at Net Asset Value Per Share [Member] | U.S. stock index fund [Member] | Pension Plan [Member] | Fair Value, Recurring [Member]
Defined Benefit Plan Disclosure [Line Items]
Unfunded Commitment		$ 0	$ 0

[1] U.S. equities.  These investments are held in common and preferred stock of U.S. corporations and American Depositary Receipts (ADRs) traded on U.S. exchanges. Common and preferred shares and ADRs are traded actively on exchanges, and price quotes for these shares are readily available. These investments are classified as Level 1 in the valuation hierarchy.

[2] International equities.  These investments are held in common and preferred stock issued by non-U.S. corporations. Common and preferred shares are traded actively on exchanges, and price quotes for these shares are readily available. These investments are classified as Level 1 in the valuation hierarchy.

[3] Short-term investment funds.  These investments include commingled funds that are primarily held in U.S. Treasury securities. The funds are valued using the net asset value (NAV) provided by the administrator of the funds and reviewed by the Company.

[4] Private investment funds. This category includes a commingled fund and a private investment fund. The commingled fund invests in a diversified mix of publicly traded securities (U.S. and international stocks) and private companies. The private investment fund invests in non-public companies. The funds are valued using the NAV provided by the administrator of the funds and reviewed by the Company. The NAV is based on the value of the underlying assets owned by the fund, minus liabilities and divided by the number of units outstanding.

[5] U.S. stock index fund. This fund consists of investments held in common stock, plus an uninvested cash portion comprising less than 1% of fund value, that together are designed to track the performance of the S&P 500 Index. The fund is valued using the NAV provided by the administrator of the fund and reviewed by the Company. The NAV is based on the value of the underlying assets owned by the fund, minus liabilities and divided by the number of units outstanding.