Capital and Operating Leases (Components of the Net Investment in the Capital Leases) (Details) $ in Millions	Dec. 31, 2017 USD ($)
Capital Leases of Lessor [Abstract]
2018	$ 13
2019	10
2020	9
2021	0
2022	0
2023 and thereafter	1
Total minimum future lease receipts	33
Residual value of leased pipeline	40
Less unearned income	(15)
Net investment in capital lease	58
Less current portion	(7)
Capital lease, noncurrent	$ 51

Amount of minimum lease payments to be received by the lessor for capital leases.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 840
-SubTopic 30
-Section 50
-Paragraph 4
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=84165051&loc=d3e45377-112738

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Amount of minimum lease payments to be received by the lessor for capital leases in the next fiscal year following the latest fiscal year. Excludes interim and annual periods when interim periods are reported on a rolling approach, from latest balance sheet date.

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Amount of minimum lease payments to be received by the lessor for capital leases after the fifth fiscal year following the latest fiscal year. Excludes interim and annual periods when interim periods are reported on a rolling approach, from latest balance sheet date.

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Amount of minimum lease payments to be received by the lessor for capital leases in the fifth fiscal year following the latest fiscal year. Excludes interim and annual periods when interim periods are reported on a rolling approach, from latest balance sheet date.

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Amount of minimum lease payments to be received by the lessor for capital leases in the fourth fiscal year following the latest fiscal year. Excludes interim and annual periods when interim periods are reported on a rolling approach, from latest balance sheet date.

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Amount of minimum lease payments to be received by the lessor for capital leases in the third fiscal year following the latest fiscal year. Excludes interim and annual periods when interim periods are reported on a rolling approach, from latest balance sheet date.

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Amount of minimum lease payments to be received by the lessor for capital leases in the second fiscal year following the latest fiscal year. Excludes interim and annual periods when interim periods are reported on a rolling approach, from latest balance sheet date.

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The net amount due within one year of the balance sheet date or the normal operating cycle, if longer, consisting of: (a) minimum lease payments due on direct financing leases, (b) unguaranteed residual value, and (c) any unamortized initial direct costs, less: (i) executory costs, (ii) unearned income, and (iii) the accumulated allowance for uncollectible minimum lease payments.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 840
-SubTopic 30
-Section 50
-Paragraph 4
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=84165051&loc=d3e45377-112738

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The net amount due after one year of the balance sheet date or beyond the normal operating cycle, if longer, consisting of: (a) minimum lease payments due on direct financing leases, (b) unguaranteed residual value, and (c) any unamortized initial direct costs; less: (i) executory costs, (ii) unearned income, and (iii) the accumulated allowance for uncollectible minimum lease payments.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 840
-SubTopic 30
-Section 50
-Paragraph 4
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=84165051&loc=d3e45377-112738

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The net investment in direct financing leases as of the balance sheet date consisting of: (a) minimum lease payments due on direct financing leases, (b) unguaranteed residual value, and (c) any unamortized initial direct costs; less: (i) executory costs, (ii) unearned income, and (iii) the accumulated allowance for uncollectible minimum lease payments.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 840
-SubTopic 30
-Section 50
-Paragraph 4
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=84165051&loc=d3e45377-112738

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The remaining (unamortized) difference between the gross investment in a direct financing lease and the cost or carrying amount, if different, of the leased property as of the balance sheet date.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 840
-SubTopic 30
-Section 50
-Paragraph 4
-Subparagraph (a)(4)
-URI http://asc.fasb.org/extlink&oid=84165051&loc=d3e45377-112738

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- Definition

The estimate of the lease property's economic value at the end of the direct financing lease term excluding any amounts guaranteed by either the lessee or a third-party.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 840
-SubTopic 30
-Section 50
-Paragraph 4
-Subparagraph (a)(2)
-URI http://asc.fasb.org/extlink&oid=84165051&loc=d3e45377-112738

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- References

No definition available.

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