Fair Value Measurements (Carrying Amounts and Estimated Fair Values of Financial Instruments) (Details) - USD ($) $ in Thousands		Dec. 31, 2024	Dec. 31, 2023
Carrying Amount [Member] | Level 2 [Member]
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Long-term debt, including current portion	[1]	$ (1,036,569)	$ (1,035,654)
Carrying Amount [Member] | Level 2 [Member] | Interest rate contracts [Member]
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Derivative assets related to interest rate swaps		138,354	129,125
Carrying Amount [Member] | Level 2 [Member] | Term Loans [Member]
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Long-term debt, including current portion		(1,036,569)	(969,919)
Carrying Amount [Member] | Level 2 [Member] | Revenue bonds [Member]
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Long-term debt, including current portion		0	(65,735)
Carrying Amount [Member] | Level 3 [Member]
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Company owned life insurance		6,026	5,220
Fair Value [Member] | Level 2 [Member]
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Long-term debt, including current portion	[1]	(1,035,608)	(1,030,504)
Fair Value [Member] | Level 2 [Member] | Interest rate contracts [Member]
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Derivative assets related to interest rate swaps		138,354	129,125
Fair Value [Member] | Level 2 [Member] | Term Loans [Member]
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Long-term debt, including current portion		(1,035,608)	(965,718)
Fair Value [Member] | Level 2 [Member] | Revenue bonds [Member]
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Long-term debt, including current portion		0	(64,786)
Fair Value [Member] | Level 3 [Member]
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Company owned life insurance		$ 6,026	$ 5,220

[1] 1. The carrying amount of long-term debt includes principal and unamortized discounts.