XML 64 R49.htm IDEA: XBRL DOCUMENT v3.25.3
Exchangeable Senior Notes (Details)
 3 Months Ended 9 Months Ended
Sep. 29, 2025
USD ($)
$ / shares
$ / Unit
Sep. 30, 2025
USD ($)
$ / shares
Sep. 30, 2025
USD ($)
$ / shares
Sep. 30, 2024
USD ($)
Sep. 24, 2025
$ / shares
Debt Instrument [Line Items]          
Debt Conversion, Converted Instrument, Amount     $ 0 $ 100,000,000  
Closing price of common stock (in dollars per share) | $ / shares   $ 74.34 $ 74.34    
Capped call transactions premium   $ 35,000,000 $ 35,000,000 0  
Boston Properties Limited Partnership          
Debt Instrument [Line Items]          
Debt Conversion, Converted Instrument, Amount     0 100,000,000  
Capped call transactions premium     35,000,000 $ 0  
2.00% unsecured exchangeable senior notes | Convertible Debt          
Debt Instrument [Line Items]          
Debt $ 1,000,000,000        
Debt Instrument, Interest Rate, Stated Percentage 2.00%        
Debt Instrument, Maturity Date Oct. 01, 2030        
Proceeds From Convertible Debt, Net of Issuance and Hedging Costs $ 975,100,000        
Interest Expense, Nonoperating   100,000 100,000    
Amortization of Debt Issuance Costs   $ 28,000 $ 28,000    
Debt Instrument, Interest Rate, Effective Percentage 2.498%        
Unamortized Debt Issuance Expense $ 24,900,000        
Debt Instrument, Convertible, Earliest Date Jul. 01, 2030        
Debt Conversion, Converted Instrument, Amount $ 1,000        
Debt Instrument, Convertible, Conversion Price | $ / shares $ 92.44        
Debt Instrument, Convertible, Terms of Conversion Feature Before July 1, 2030, noteholders will have the right to exchange their Notes only upon the occurrence of certain events. From and after July 1, 2030, noteholders may exchange their Notes at any time at their election until the close of business on the second scheduled trading day immediately before the maturity date of the Notes. Exchanges will be settled in cash up to the aggregate principal amount of the Notes to be exchanged and, if applicable, cash, shares of BXP’s common stock or a combination thereof, at BPLP’s election, in respect of the remainder (if any) of BPLP’s exchange obligations in excess of the aggregate principal amount of the Notes being exchanged. The initial exchange rate is 10.8180 shares of BXP’s common stock per $1,000 principal amount of Notes, which represents an initial exchange price of approximately $92.44 per share of BXP’s common stock.        
Debt Instrument, Convertible, Exchange Premium Percentage 22.50%        
Closing price of common stock (in dollars per share) | $ / shares         $ 75.46
Debt Instrument, Redemption Price, Percentage 130.00%        
Debt Instrument, Redemption, Description The Notes will be redeemable, in whole or in part (subject to certain limitations), for cash at BPLP’s option at any time, and from time to time, on or after October 6, 2028 and on or before the 41st scheduled trading day immediately before the maturity date of the notes, but only if the last reported sale price per share of BXP’s common stock exceeds 130% of the exchange price of the Notes for a specified period of time and certain liquidity conditions are satisfied. BPLP may also redeem the Notes, in whole or in part (subject to certain limitations), for cash at any time, and from time to time, if BXP’s Board of Directors (or a committee thereof) determines such redemption is necessary to preserve BXP’s status as a real estate investment trust. In either case, the redemption price will be equal to the principal amount of the Notes to be redeemed, plus accrued and unpaid interest, if any, to, but excluding, the redemption date.        
2.00% unsecured exchangeable senior notes | Convertible Debt | Call Option          
Debt Instrument [Line Items]          
Derivative, Cap Price | $ / Unit 105.64        
Debt Instrument, Convertible, Associated Derivative Transactions, Description In conjunction with the issuance of the Notes, the Company entered into Capped Call Transactions with certain financial institutions. The Capped Call Transactions cover, subject to customary adjustments, the number of shares of BXP’s common stock initially underlying the Notes. The Capped Call Transactions are expected generally to reduce the potential dilution to BXP’s common stock upon any exchange of Notes and/or offset any cash payments BPLP is required to make in excess of the principal amount of exchanged Notes, as the case may be, with such reduction and/or offset subject to a cap. The cap price of the Capped Call Transactions is initially $105.64 per share, and is subject to certain adjustments under the terms of the Capped Call Transactions. The Capped Call Transactions will expire upon the maturity of the Notes, if not earlier exercised or terminated.        
Capped call transactions premium $ 35,000,000        
2.00% unsecured exchangeable senior notes | Convertible Debt | Per $1,000 principal amount          
Debt Instrument [Line Items]          
Debt Instrument, Convertible, Conversion Ratio 10.8180        
2.00% unsecured exchangeable senior notes | Convertible Debt | Boston Properties Limited Partnership          
Debt Instrument [Line Items]          
Debt $ 1,000,000,000        
Debt Instrument, Interest Rate, Stated Percentage 2.00%