Long-Term Debt (Term Loan) (Details) - Term Loan [Member] $ in Thousands	3 Months Ended
Mar. 31, 2016 USD ($)
Debt Instrument [Line Items]
Face amount	$ 2,035,000
Due date	Oct. 01, 2019
Each Quarter through March 31, 2017 [Member]
Debt Instrument [Line Items]
Maximum funded debt to EBITDA ratio	625.00%
Each Quarter after March 31, 2017 [Member]
Debt Instrument [Line Items]
Maximum funded debt to EBITDA ratio	550.00%
Maximum funded debt to EBITDA ratio, subject to future acquisitions	600.00%
Maximum [Member]
Debt Instrument [Line Items]
Face amount	$ 2,035,000
Maximum [Member] \| Applicable Margin on LIBOR Loan [Member]
Debt Instrument [Line Items]
Basis spread on variable rate	2.50%
Maximum [Member] \| Applicable Margin on Base Rate Loan [Member]
Debt Instrument [Line Items]
Basis spread on variable rate	1.50%
Minimum [Member] \| Applicable Margin on LIBOR Loan [Member]
Debt Instrument [Line Items]
Basis spread on variable rate	1.50%
Minimum [Member] \| Applicable Margin on Base Rate Loan [Member]
Debt Instrument [Line Items]
Basis spread on variable rate	0.50%

Increase in maximum funded debt to EBITDA ratio.

No definition available.

Name:	sun_IncreaseInMaximumFundedDebtToEBITDARatio
Namespace Prefix:	sun_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

Maximum funded debt to EBITDA ratio.

+ References

No definition available.

+ Details

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Namespace Prefix:	sun_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

Percentage points added to the reference rate to compute the variable rate on the debt instrument.

+ References

No definition available.

+ Details

Name:	us-gaap_DebtInstrumentBasisSpreadOnVariableRate1
Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Face (par) amount of debt instrument at time of issuance.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 835
-SubTopic 30
-Section 55
-Paragraph 8
-URI http://asc.fasb.org/extlink&oid=34725769&loc=d3e28878-108400

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 835
-SubTopic 30
-Section 45
-Paragraph 2
-URI http://asc.fasb.org/extlink&oid=6451184&loc=d3e28551-108399

+ Details

Name:	us-gaap_DebtInstrumentFaceAmount
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

No definition available.

+ Details

Name:	us-gaap_DebtInstrumentLineItems
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

Date when the debt instrument is scheduled to be fully repaid, in CCYY-MM-DD format.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02.22(a)(2))
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

+ Details

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:dateItemType
Balance Type:	na
Period Type:	duration

- Details

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Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_DebtInstrumentAxis=sun_TermLoanRequirementForEachQuarterThroughMarch312017Member
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_DebtInstrumentAxis=sun_TermLoanRequirementForEachFiscalQuarterAfterMarch312017Member
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_RangeAxis=us-gaap_MaximumMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_VariableRateAxis=sun_ApplicableMarginOnLIBORLoanMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_VariableRateAxis=sun_ApplicableMarginOnBaseRateLoanMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_RangeAxis=us-gaap_MinimumMember
Namespace Prefix:
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Period Type: