UNIT-BASED COMPENSATION PLANS - Additional Information (Detail) (USD $)	3 Months Ended	12 Months Ended						1 Months Ended	12 Months Ended			1 Months Ended	6 Months Ended	12 Months Ended	1 Months Ended	12 Months Ended											3 Months Ended		3 Months Ended		3 Months Ended		12 Months Ended																	12 Months Ended
	Dec. 31, 2010	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009	Dec. 31, 2011 Unit Option	Dec. 31, 2010 Unit Option	Dec. 31, 2009 Unit Option	May 31, 2004 Class B Units	Dec. 31, 2011 Long Term Incentive Plan 2009	Dec. 31, 2010 Long Term Incentive Plan 2009	Dec. 31, 2009 Long Term Incentive Plan 2009	Aug. 31, 2006 Management Units	Jun. 30, 2007 Management Units	Dec. 31, 2006 Management Units	Aug. 31, 2006 Management Units Class B Units	Dec. 31, 2011 Override Units Year		Dec. 31, 2010 Override Units	Dec. 31, 2009 Override Units Year		Dec. 31, 2011 Value B Units	Dec. 31, 2011 Value B Units Minimum	Dec. 31, 2011 Value B Units Maximum	Dec. 31, 2011 Value A Units	Dec. 31, 2011 Value A Units Maximum	Dec. 31, 2010 Operating Units Year	Mar. 31, 2011 Value N-1 Units	Dec. 31, 2011 Value N-1 Units	Mar. 31, 2011 Value N-2 Units	Dec. 31, 2011 Value N-2 Units	Mar. 31, 2011 Value N-2 Units Minimum	Mar. 31, 2011 Value N-2 Units Maximum	Dec. 31, 2011 Long Term Incentive Plans Year		Dec. 31, 2010 Long Term Incentive Plans		Dec. 31, 2011 Long Term Incentive Plans Phantom Stock Units	Dec. 31, 2010 Long Term Incentive Plans Phantom Stock Units	Dec. 31, 2011 Long Term Incentive Plans Phantom Stock Units Employee	Dec. 31, 2011 Long Term Incentive Plans Phantom Stock Units Director	Dec. 31, 2011 Long Term Incentive Plans Performance Share Units Employee	Dec. 31, 2011 Long Term Incentive Plans Performance Based Units	Dec. 31, 2011 Long Term Incentive Plans Minimum	Dec. 31, 2011 Long Term Incentive Plans Minimum Phantom Stock Units	Dec. 31, 2011 Long Term Incentive Plans Maximum	Dec. 31, 2011 Long Term Incentive Plans Maximum Phantom Stock Units	Dec. 31, 2011 Buckeye Partners LP Unit Deferral and Incentive Plan	Dec. 31, 2010 Buckeye Partners LP Unit Deferral and Incentive Plan	Dec. 31, 2009 Buckeye Partners LP Unit Deferral and Incentive Plan	Dec. 31, 2011 Buckeye Partners LP Unit Deferral and Incentive Plan Phantom Stock Units
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Class B units exchanged into management units															1,362,000
Management units, vested														272,400	953,400																		17,553		18,642
Percentage of management units vested upon exchange															70.00%
Market value of management units, vested per share												$ 17.00																					$ 55.53	[1]	$ 39.20	[1]
Management units, expected to vest															408,600
Market value of equity unit, vested												$ 4,600,000				$ 410,700,000	[2]		$ 439,060,000	[3]						$ 822,200,000							$ 975,000		$ 731,000
Percentage of management units expected to vest															30.00%
Expected life in years																1.0	[2]		3.4	[3]						1
Compensation expense		0	1,200,000	1,300,000					9,200,000	7,700,000	3,100,000		1,100,000	3,500,000		0		1,200,000	1,300,000
Vesting term															3 years																											3 years	1 year	1 year	3 years	3 years
Risk-free interest rate																0.30%	[2]		1.80%	[3]						0.29%
Conversion rate, LP units per common unit													0.705
Compensation expense, additional expense	21,100,000		21,100,000
Volatility																0.25%	[2]		0.45%	[3]						25.00%
Expected dividend																										0
Compensation Plan, units issued by MainLine, L.P. that owned BGH GP								16,216,668
Vesting rights description																					Vest based on the occurrence of an exit event, an investment return of 3.5 times the original investment and an internal rate of return of at least 10% or on a pro-rata basis on an investment return ranging from 2.0 to 3.5 times the original investment and an internal rate of return of at least 10%.						The Value N-1 Units will participate in distributions by BGH GP based on the occurrence of an exit event and an investment return of 2.0 times the original investment up to aggregate distributions of $3.0 million.		The Value N-2 Units will participate in distributions by BGH GP based on the occurrence of an exit event and an investment return of 2.5 times the original investment or on a pro-rata basis on an investment return ranging from 2.0 to 2.5 times the original investment up to aggregate distributions of $5.0 million.
Internal rate of return																						10.00%			10.00%
Rate of return on investment																					3.5	2.0	3.5	2			2.0		2.5		2.0	2.5
Aggregate distributions on unit based compensation plan																											3,000,000		5,000,000
Grant date fair values unvested units																					2,200,000							900,000		1,100,000
Total intrinsic value of options exercised					2,500,000	1,700,000	500,000
LP Units, available for issuance					333,000																												1,500,000
Compensation expense expected to be recognized					0																												13,700,000
LP Units, additional units available for issuance																																	877,969
Fair value of options vested					200,000	400,000	400,000
LP Units, maximum grant to any individual per year																																	100,000
Percentage of compensation award allowed to be deferred																																															50.00%	50.00%	50.00%
Compensation awards deferred																																															700,000	1,600,000
Stock award, granted																																	251,184		259,336				112,257	14,000	124,927									50,660
Expiration date from the date of grant																																										10 years
Phantom unit distribution, amount paid																																					$ 1,200,000	$ 600,000
Unrecognized compensation cost, weighted average period of recognition (in years)																																	1.2

[1] Determined by dividing the aggregate grant date fair value of awards by the number of awards issued. The weighted-average grant date fair value per LP Unit for forfeited and vested awards is determined before an allowance for forfeitures.

[2] The assumptions were used for grants of the Value N-1 and N-2 Units during the period.

[3] The assumptions were used for grants of the Value A, Value B, and Operating Units during the period.