Fair Value Measurements Debt at at Carrying and Fair Value (Details) - USD ($) $ in Thousands	Mar. 31, 2023	Dec. 31, 2022
Liabilities:
Total long-term debt	$ 6,666,416	$ 6,663,373
Carrying Value [Member] | Level 2 [Member]
Liabilities:
Notes Receivable, Fair Value Disclosure	47,200	55,000
Subsidiaries [Member]
Liabilities:
Total long-term debt	4,787,241	4,786,765
Discounted cash flow [Member] | Fair Value [Member]
Liabilities:
Long-term Debt, Excluding Current Maturities, Fair Value Disclosure	6,411,732	6,184,097
Discounted cash flow [Member] | Fair Value [Member] | Level 2 [Member]
Liabilities:
Long-term debt (fixed-rate), net of discount	6,377,432	6,149,797
Long-term debt (variable-rate)	34,300	34,300
Discounted cash flow [Member] | Carrying Value [Member]
Liabilities:
Long-term Debt, Excluding Current Maturities, Fair Value Disclosure	6,666,416	6,663,373
Discounted cash flow [Member] | Carrying Value [Member] | Level 2 [Member]
Liabilities:
Long-term debt (fixed-rate), net of discount	6,632,116	6,629,073
Long-term debt (variable-rate)	34,300	34,300
Debt issuance costs	21,100	21,500
Discounted cash flow [Member] | Subsidiaries [Member] | Fair Value [Member]
Liabilities:
Total long-term debt	4,547,348	4,379,010
Discounted cash flow [Member] | Subsidiaries [Member] | Fair Value [Member] | Level 2 [Member]
Liabilities:
Long-term debt (fixed-rate), net of discount	4,547,348	4,379,010
Discounted cash flow [Member] | Subsidiaries [Member] | Carrying Value [Member]
Liabilities:
Total long-term debt	4,787,241	4,786,765
Discounted cash flow [Member] | Subsidiaries [Member] | Carrying Value [Member] | Level 2 [Member]
Liabilities:
Long-term debt (fixed-rate), net of discount	4,787,241	4,786,765
Debt issuance costs	$ 21,000	$ 21,400