Inventory (Parenthetical) (Detail)	Dec. 31, 2011 gal	Dec. 31, 2010 gal
Inventory Disclosure [Line Items]
Ending inventory	99,600,000	134,900,000

Ending inventory in gallons of refined petroleum products at balance sheet date.

No definition available.

Name:	bpl_RefinedPetroleumProducts
Namespace Prefix:	bpl_
Data Type:	xbrli:decimalItemType
Balance Type:	na
Period Type:	instant