Debt and Financing Arrangements Long-Term Debt Instruments (Details) - USD ($) $ in Thousands	3 Months Ended
Mar. 31, 2022	Mar. 31, 2021	Dec. 31, 2021
Debt Instrument [Line Items]
Long-Term Debt	$ 5,265,835		$ 5,269,024
Long-term debt due within one year	26,182		25,594
Proceeds from other financing obligations	2,843	$ 817
Dalton Expansion Project
Debt Instrument [Line Items]
Long-Term Debt	251,200		251,900
Long-term debt due within one year	2,600		2,500
Atlantic Sunrise Project
Debt Instrument [Line Items]
Long-Term Debt	801,500		807,100
Long-term debt due within one year	22,900		22,400
Proceeds from other financing obligations	300	$ 800
Leidy South Project
Debt Instrument [Line Items]
Long-Term Debt	73,900		71,500
Long-term debt due within one year	700		$ 700
Proceeds from other financing obligations	$ 2,600

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- Definition

Amount, after unamortized (discount) premium and debt issuance costs, of long-term debt, classified as current. Includes, but not limited to, notes payable, bonds payable, debentures, mortgage loans and commercial paper. Excludes capital lease obligations.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02.19,20)
-URI http://asc.fasb.org/extlink&oid=120391452&loc=d3e13212-122682

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Amount after unamortized (discount) premium and debt issuance costs of long-term debt classified as noncurrent and excluding amounts to be repaid within one year or the normal operating cycle, if longer. Includes, but not limited to, notes payable, bonds payable, debentures, mortgage loans and commercial paper. Excludes capital lease obligations.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02.22)
-URI http://asc.fasb.org/extlink&oid=120391452&loc=d3e13212-122682

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Amount of cash inflow from issuance of long-term debt classified as other.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 14
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=123570139&loc=d3e3255-108585

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