BUSINESS SEGMENTS - Adjusted EBITDA from Continuing Operations (Details) - USD ($) $ in Thousands	3 Months Ended	9 Months Ended
Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Segment information
Adjusted EBITDA	$ 277,318	$ 271,649	$ 824,018	$ 772,864
Reconciliation of Net Income to Adjusted EBITDA:
Net income	120,224	160,270	362,912	439,746
Less: Net income attributable to noncontrolling interests	(4,037)	(3,896)	(10,427)	(11,803)
Net income attributable to Buckeye Partners, L.P.	116,187	156,374	352,485	427,943
Add: Interest and debt expense	56,561	48,476	168,870	144,093
Income tax expense	448	308	1,709	896
Depreciation and amortization	65,661	63,472	195,987	188,220
Gains on property damage recoveries			(4,621)	(5,700)
Earnings from the equity-method investment in VTTI	(9,232)	(2,901)	(22,710)	(8,459)
Adjusted EBITDA	277,318	271,649	824,018	772,864
Segment Reconciling Items
Reconciliation of Net Income to Adjusted EBITDA:
Non-cash unit-based compensation expense	8,176	8,853	25,756	22,912
Acquisition and transition expense	1,447	309	3,275	479
Hurricane-related costs	1,804	0	4,820	0
Proportionate share of Adjusted EBITDA for the equity-method investment in VTTI	33,430	0	90,848	0
Less: Amortization of unfavorable storage contracts	0	(443)	0	(5,979)
Gains on property damage recoveries	0	(5,700)	(4,621)	(5,700)
Segment Reconciling Items \| VTTI B.V.
Reconciliation of Net Income to Adjusted EBITDA:
Earnings from the equity-method investment in VTTI	(6,396)	0	(15,111)	0
Domestic Pipelines & Terminals
Segment information
Adjusted EBITDA	138,880	152,785	413,710	423,245
Reconciliation of Net Income to Adjusted EBITDA:
Adjusted EBITDA	138,880	152,785	413,710	423,245
Global Marine Terminals
Segment information
Adjusted EBITDA	128,696	110,705	391,084	325,710
Reconciliation of Net Income to Adjusted EBITDA:
Adjusted EBITDA	128,696	110,705	391,084	325,710
Global Marine Terminals \| VTTI B.V.
Reconciliation of Net Income to Adjusted EBITDA:
Earnings from the equity-method investment in VTTI	(6,396)	0	(15,111)	0
Merchant Services
Segment information
Adjusted EBITDA	9,742	8,159	19,224	23,909
Reconciliation of Net Income to Adjusted EBITDA:
Adjusted EBITDA	$ 9,742	$ 8,159	$ 19,224	$ 23,909

Represents earnings (loss) before interest, income taxes, depreciation and amortization from continuing operations.

No definition available.

Name:	bpl_AdjustedEarningsBeforeInterestTaxesDepreciationAndAmortizationFromContinuingOperations
Namespace Prefix:	bpl_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Adjusted Earnings Before Interest Taxes Depreciation And Amortization From Continuing Operations Attributable To Equity Method Investment

+ References

No definition available.

+ Details

Name:	bpl_AdjustedEarningsBeforeInterestTaxesDepreciationAndAmortizationFromContinuingOperationsAttributableToEquityMethodInvestment
Namespace Prefix:	bpl_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Gain (Loss) on Asset Recoveries

+ References

No definition available.

+ Details

Name:	bpl_GainLossonAssetRecoveries
Namespace Prefix:	bpl_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

The aggregate amount of noncash unit-based compensation expense.

+ References

No definition available.

+ Details

Name:	bpl_NonCashUnitBasedCompensationExpense
Namespace Prefix:	bpl_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Amount of amortization of acquired leases acquired as part of a real property acquisition at below market lease rate with a finite life.

+ References

No definition available.

+ Details

Name:	us-gaap_AmortizationOfBelowMarketLease
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

This element represents acquisition-related costs incurred to effect a business combination which costs have been expensed during the period. Such costs include finder's fees; advisory, legal, accounting, valuation, and other professional or consulting fees; general administrative costs, including the costs of maintaining an internal acquisitions department; and may include costs of registering and issuing debt and equity securities.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 805
-SubTopic 10
-Section 25
-Paragraph 23
-URI http://asc.fasb.org/extlink&oid=84229725&loc=d3e1043-128460

+ Details

Name:	us-gaap_BusinessCombinationAcquisitionRelatedCosts
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

The aggregate expense recognized in the current period that allocates the cost of tangible assets, intangible assets, or depleting assets to periods that benefit from use of the assets.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 28
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=98514028&loc=d3e3602-108585

+ Details

Name:	us-gaap_DepreciationDepletionAndAmortization
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Amount after tax of income (loss) from continuing operations attributable to the parent.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 28
-URI http://asc.fasb.org/extlink&oid=98514028&loc=d3e3602-108585

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 260
-SubTopic 10
-Section 50
-Paragraph 1
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=6371337&loc=d3e3550-109257

Reference 3: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 225
-SubTopic 10
-Section S99
-Paragraph 2
-Subparagraph (SX 210.5-03.13)
-URI http://asc.fasb.org/extlink&oid=63488584&loc=d3e20235-122688

Reference 4: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 810
-SubTopic 10
-Section 45
-Paragraph 18
-URI http://asc.fasb.org/extlink&oid=96868048&loc=SL4613673-111683

+ Details

Name:	us-gaap_IncomeLossFromContinuingOperations
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Amount after tax of income (loss) from continuing operations including portion attributable to the noncontrolling interest.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 810
-SubTopic 10
-Section 45
-Paragraph 19
-URI http://asc.fasb.org/extlink&oid=96868048&loc=SL4569616-111683

+ Details

Name:	us-gaap_IncomeLossFromContinuingOperationsIncludingPortionAttributableToNoncontrollingInterest
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

This item represents the entity's proportionate share for the period of the net income (loss) of its investee (such as unconsolidated subsidiaries and joint ventures) to which the equity method of accounting is applied. This item includes income or expense related to stock-based compensation based on the investor's grant of stock to employees of an equity method investee.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 225
-SubTopic 10
-Section S99
-Paragraph 2
-Subparagraph (SX 210.5-03(12))
-URI http://asc.fasb.org/extlink&oid=63488584&loc=d3e20235-122688

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 944
-SubTopic 225
-Section S99
-Paragraph 1
-Subparagraph (SX 210.7-04(10))
-URI http://asc.fasb.org/extlink&oid=6879464&loc=d3e573970-122913

Reference 3: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 28
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=98514028&loc=d3e3602-108585

Reference 4: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 323
-SubTopic 10
-Section 45
-Paragraph 1
-URI http://asc.fasb.org/extlink&oid=66022249&loc=d3e33749-111570

Reference 5: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 225
-Section S99
-Paragraph 1
-Subparagraph (SX 210.9-04(13)(f))
-URI http://asc.fasb.org/extlink&oid=6879574&loc=d3e536633-122882

+ Details

Name:	us-gaap_IncomeLossFromEquityMethodInvestments
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Amount of current income tax expense (benefit) and deferred income tax expense (benefit) pertaining to continuing operations.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 740
-SubTopic 10
-Section 50
-Paragraph 9
-Subparagraph (a),(b)
-URI http://asc.fasb.org/extlink&oid=84230637&loc=d3e32639-109319

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 235
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.4-08.(h))
-URI http://asc.fasb.org/extlink&oid=26873400&loc=d3e23780-122690

+ Details

Name:	us-gaap_IncomeTaxExpenseBenefit
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Interest and debt related expenses associated with nonoperating financing activities of the entity.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 835
-SubTopic 20
-Section 50
-Paragraph 1
-URI http://asc.fasb.org/extlink&oid=6450988&loc=d3e26243-108391

+ Details

Name:	us-gaap_InterestAndDebtExpense
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Amount of Net Income (Loss) attributable to noncontrolling interest.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 810
-SubTopic 10
-Section 55
-Paragraph 4J
-URI http://asc.fasb.org/extlink&oid=84234705&loc=SL4591551-111686

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 810
-SubTopic 10
-Section 50
-Paragraph 1A
-Subparagraph (a)(2)
-URI http://asc.fasb.org/extlink&oid=84161450&loc=SL4573702-111684

+ Details

Name:	us-gaap_NetIncomeLossAttributableToNoncontrollingInterest
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Amount of other expense (income) that is infrequent in occurrence or unusual in nature.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 225
-SubTopic 20
-Section 50
-Paragraph 3
-URI http://asc.fasb.org/extlink&oid=64828382&loc=d3e15138-107781

+ Details

Name:	us-gaap_OtherNonrecurringIncomeExpense
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- References

No definition available.

+ Details

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

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

- Details

Name:	us-gaap_ConsolidationItemsAxis=us-gaap_MaterialReconcilingItemsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis=bpl_VTTIB.V.Member
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_StatementBusinessSegmentsAxis=bpl_PipelinesAndTerminalsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_StatementBusinessSegmentsAxis=bpl_GlobalMarineTerminalsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_StatementBusinessSegmentsAxis=bpl_MerchantServicesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: