Debt and Financing Arrangements - Other Financing Obligations (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023	Dec. 31, 2023
Debt Instrument [Line Items]
Long-Term Debt	$ 5,223,362		$ 5,229,450
Long-term debt due within one year	32,433		31,718
Proceeds from other financing obligations	1,453	$ 3,757
Dalton Expansion Project
Debt Instrument [Line Items]
Long-Term Debt	246,300		246,800
Long-term debt due within one year	3,100		3,000
Atlantic Sunrise Project
Debt Instrument [Line Items]
Long-Term Debt	756,800		762,800
Long-term debt due within one year	28,000		27,400
Proceeds from other financing obligations	1,200	$ 3,700
Leidy South Project
Debt Instrument [Line Items]
Long-Term Debt	74,700		75,000
Long-term debt due within one year	$ 1,300		$ 1,300