v2.4.0.8

Segment Information Segment Information (narrative) (Details) (767 Fifth Avenue (The GM Building) [Member]) | 0 Months Ended
--- | ---
May 31, 2013 partners
767 Fifth Avenue (The GM Building) [Member] |
Segment Reporting Information [Line Items] |
Number of Joint Venture Partners | 2

X
- Definition Number of Joint Venture Partners + References No definition available. + Details
Name: | bxp_NumberofJointVenturePartners
Namespace Prefix: | bxp_
Data Type: | xbrli:integerItemType
Balance Type: | na
Period Type: | duration

X
- Details
Name: | us-gaap_SegmentReportingInformationLineItems
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration