Condensed Financial Information - Parent Company Only (Details) - USD ($) $ in Thousands	3 Months Ended		12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Condensed Income Statements, Captions [Line Items]
Administrative and general			$ 137,437	$ 117,360	$ 113,776
Operating Loss	$ (91,696)	$ (103,163)	(323,321)	(300,455)	(263,079)
Interest expense			(131,673)	(114,617)	(100,110)
Other Income, net			23,024	15,832	19,434
Income Before Income Taxes			214,672	201,670	182,403
Income tax benefit			9,439	(7,539)	605
Net Income	80,552	83,142	224,111	194,131	183,008
Other Comprehensive Income (Loss), Net of Tax, Portion Attributable to Parent			952	192	(538)
Comprehensive Income (Loss), Net of Tax, Attributable to Parent			225,063	194,323	182,470
Condensed Balance Sheet Statements, Captions [Line Items]
Cash and cash equivalents	4,283	9,164	4,283	9,164	8,489
Accounts receivable, net	187,764	212,257	187,764	212,257
Assets, Current	418,186	407,006	418,186	407,006
Deferred tax assets	295,486	287,215	295,486	287,215
Other noncurrent assets	59,063	52,314	59,063	52,314
Total assets	7,997,524	7,600,652	7,997,524	7,600,652
Other noncurrent liabilities	316,044	332,372	316,044	332,372
Liabilities	5,139,824	4,815,338	5,139,824	4,815,338
Stockholders' Equity Attributable to Parent	2,857,700	2,785,314	2,857,700	2,785,314	2,665,183	$ 2,339,713
Liabilities and Equity	7,997,524	7,600,652	7,997,524	7,600,652
Short-Term Debt	100,000	0	100,000	0
Accounts payable	111,794	124,340	111,794	124,340
Accrued expenses and other	254,599	246,167	254,599	246,167
Liabilities, Current	802,200	534,898	802,200	534,898
Long-term debt	2,695,343	2,684,635	2,695,343	2,684,635
Deferred income taxes	958,916	887,735	958,916	887,735
Condensed Cash Flow Statements, Captions [Line Items]
Net Income	80,552	83,142	224,111	194,131	183,008
Amortization of debt issuance costs, discount and deferred hedge gain			4,647	5,142	5,321
Stock-based compensation costs			4,721	5,176	5,488
Deferred income taxes			(8,969)	6,584	(8,992)
Accounts receivable			24,493	32,695	(46,282)
Accounts payable			7,399	(54,722)	50,537
Accrued expenses			9,748	(3,377)	16,846
Other noncurrent assets and liabilities			(11,945)	(30,583)	(21,872)
Net Cash Provided by (Used in) Operating Activities			406,741	489,231	307,242
Net Cash Provided by (Used in) Investing Activities			(554,463)	(570,812)	(516,859)
Dividends on common stock			(158,589)	(154,050)	(140,062)
Issuances of short-term borrowings			100,000	0	0
Line of credit borrowings (repayments), net			95,000	(132,000)	77,000
Treasury stock activity			1,192	1,069	603
Financing costs			(1,051)	(4,327)	(1,194)
Net Cash Provided by (Used in) Financing Activities			151,552	84,305	213,318
Net Increase in Cash and Cash Equivalents			3,830	2,724	3,701
Total cash, cash equivalents, and restricted cash shown in the Consolidated Statements of Cash Flows	29,017	25,187	29,017	25,187	22,463	$ 18,762
Parent Company Condensed Income Statement
Condensed Income Statements, Captions [Line Items]
Administrative and general			1,134	231
Operating Expenses			1,134	231
Operating Loss			1,134	231
Interest expense			(4,683)	0
Earnings from investments in subsidiaries, net of tax			207,650	83,142
Other Income, net			212	230
Income Before Income Taxes			202,045	83,141
Income tax benefit			22,066	0
Net Income			224,111	83,141
Other Comprehensive Income (Loss), Net of Tax, Portion Attributable to Parent			952	365
Comprehensive Income (Loss), Net of Tax, Attributable to Parent			225,063	83,506
Condensed Balance Sheet Statements, Captions [Line Items]
Cash and cash equivalents	726	59	726	59
Accounts receivable, net	1,689	207	1,689	207
Assets, Current	2,415	266	2,415	266
Equity Method Investments	2,996,648	2,784,924	2,996,648	2,784,924
Deferred tax assets	9,578	0	9,578	0
Other noncurrent assets	4,613	4,063	4,613	4,063
Total assets	3,013,254	2,789,253	3,013,254	2,789,253
Other noncurrent liabilities	12,807	3,939	12,807	3,939
Liabilities	155,554	3,939	155,554	3,939
Stockholders' Equity Attributable to Parent	2,857,700	2,785,314	2,857,700	2,785,314
Liabilities and Equity	3,013,254	2,789,253	3,013,254	2,789,253
Short-Term Debt	100,000	0	100,000	0
Accounts payable	2,742	0	2,742	0
Accrued expenses and other	21	0	21	0
Liabilities, Current	102,763	0	102,763	0
Long-term debt	36,901	0	36,901	0
Deferred income taxes	3,083	0	3,083	0
Condensed Cash Flow Statements, Captions [Line Items]
Net Income			224,111	83,141
Equity in earnings from subsidiaries, net of tax			(207,650)	(83,142)
Cash dividends received from subsidiaries			91,183	39,042
Amortization of debt issuance costs, discount and deferred hedge gain			25	0
Stock-based compensation costs			50	0
Deferred income taxes			(18,588)	0
Accounts receivable			(1,483)	(207)
Accounts payable			684	0
Accrued expenses			(219)	0
Other noncurrent assets and liabilities			(2,272)	0
Net Cash Provided by (Used in) Operating Activities			85,841	38,834
Contributions to subsidiaries			(64,777)	0
Return of capital from subsidiaries			0	0
Net Cash Provided by (Used in) Investing Activities			(64,777)	0
Dividends on common stock			(158,589)	(39,002)
Issuances of short-term borrowings			100,000	0
Line of credit borrowings (repayments), net			37,000	0
Treasury stock activity			1,192	351
Financing costs			0	(124)
Net Cash Provided by (Used in) Financing Activities			(20,397)	(38,775)
Net Increase in Cash and Cash Equivalents			667	59
Total cash, cash equivalents, and restricted cash shown in the Consolidated Statements of Cash Flows	$ 726	$ 59	726	59	$ 0
Condensed Financial Information - Parent Company Only [Line Items]
Proceeds from Contributions from Affiliates			$ (91,200)	$ (39,000)