Commitments and Contingencies Legal Proceedings (Details) - Boardwalk GP, LP $ in Millions	Nov. 12, 2021 USD ($)
Legal damages awarded to other party (approximately)	$ 690.0
Pre-judgment interest awarded to other party (approximately)	$ 166.0

Pre-judgment interest amount awarded to other party in judgment or settlement of litigation.

No definition available.

Name:	bwp_LitigationSettlementPreJudgmentInterestAmountAwardedToOtherParty
Namespace Prefix:	bwp_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration