INVESTMENT IN UNCONSOLIDATED REAL ESTATE VENTURES - Brandywine - AI Venture (Details) - USD ($) $ in Thousands	12 Months Ended
Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Equity Method Investments and Joint Ventures [Abstract]
Net gain on real estate venture transactions	$ 56,750	$ 181	$ 26,718

Net gain (loss) on real estate venture transactions including real estate venture formation.

No definition available.

Name:	bdn_NetGainLossOnRealEstateVentureTransactionsIncludingRealEstateVentureFormation
Namespace Prefix:	bdn_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration