XML 59 R36.htm IDEA: XBRL DOCUMENT
v3.8.0.1

Mortgage Notes Payable, Net, Mezzanine Notes Payable and Outside Members’ Notes Payable Schedule of Aggregate Principal Payments On Mortgage Notes (Tables) | 12 Months Ended
--- | ---
Dec. 31, 2017
Mortgage Notes Payable [Abstract] |
Schedule of Aggregate Principal Payments On Mortgage Notes [Table Text Block] | Contractual aggregate principal payments of mortgage notes payable at December 31, 2017 are as follows:
| Principal Payments
| (in thousands)
2018 | $ | 18,633 |
2019 | 19,670 |
2020 | 20,766 |
2021 | 40,182 |
2022 | 614,710 |
Thereafter | 2,300,000 |
Total aggregate principal payments | 3,013,961 |
Deferred financing costs, net | (34,680 | )
Total carrying value of mortgage notes payable, net | $ | 2,979,281 |

X
- Definition Mortgage Notes Payable [Abstract] + References No definition available. + Details
Name: | bxp_MortgageNotesPayableAbstract
Namespace Prefix: | bxp_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Schedule of Aggregate Principal Payments On Mortgage Notes [Table Text Block] + References No definition available. + Details
Name: | bxp_ScheduleOfAggregatePrincipalPaymentsOnMortgageNotesTableTextBlock
Namespace Prefix: | bxp_
Data Type: | nonnum:textBlockItemType
Balance Type: | na
Period Type: | duration