CONDENSED CONSOLIDATED BALANCE SHEETS (Unaudited) Parenthetical	Jun. 30, 2011	Dec. 31, 2010
CONDENSED CONSOLIDATED BALANCE SHEETS (Unaudited) Parenthetical [Abstract]
Common units	175,721,916	169,721,916
Class B units	22,866,667	22,866,667

Name:

bwp_CondensedConsolidatedBalanceSheetsUnauditedParentheticalAbstract

Namespace Prefix:

bwp

Data Type:

xbrli:stringItemType

Balance Type:

na

Period Type:

duration