At The Market Stock Offering Program, Aggregate Value Of Common Stock

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At Market Stock Offering Program Maximum Length Of Sale (in years)

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Preferred Stock Redemption Price Per Share, plus accrued and unpaid dividends

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Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

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Number of shares of common stock outstanding. Common stock represent the ownership interest in a corporation.

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The number of new shares issued in the conversion of stock in a noncash (or part noncash) transaction. Noncash is defined as transactions during a period that do not result in cash receipts or cash payments in the period. "Part noncash" refers to that portion of the transaction not resulting in cash receipts or cash payments in the period.

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The number of general partner units outstanding.

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The number of limited partner units outstanding.

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The percentage rate used to calculate dividend payments on preferred stock.

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The per share liquidation preference (or restrictions) of nonredeemable preferred stock (or preferred stock redeemable solely at the option of the issuer) that has a preference in involuntary liquidation considerably in excess of the par or stated value of the shares. The liquidation preference is the difference between the preference in liquidation and the par or stated values of the share.

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The redemption (or callable) amount of currently redeemable preferred stock. Includes amounts representing dividends not currently declared or paid but which will be payable under the redemption features or for which ultimate payment is solely within the control of the issuer.

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The excess of (1) fair value of the consideration transferred to the holders of the preferred stock over (2) the carrying amount of the preferred stock in the registrant's balance sheet, during the accounting period.

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The price per share at which the preferred stock of an entity that has priority over common stock in the distribution of dividends and in the event of liquidation of the entity is redeemed or may be called at. The redemption features of this preferred stock are solely within the control of the issuer.

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Aggregate share number for all nonredeemable preferred stock (or preferred stock redeemable solely at the option of the issuer) held by stockholders. Does not include preferred shares that have been repurchased.

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Dividends paid to preferred stock holders that is redeemable solely at the option of the issuer.

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Number of share options (or share units) exercised during the current period.

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Stockholders' Equity / Partners' Capital Narrative (Details) $ / shares in Units, $ in Thousands			3 Months Ended		12 Months Ended
	Mar. 31, 2021 USD ($) shares	May 22, 2020 USD ($) yr	Mar. 31, 2021 USD ($) shares	Mar. 31, 2020 USD ($)	Dec. 31, 2020 $ / shares shares	Mar. 02, 2021 $ / shares shares	Jun. 02, 2017 USD ($)
Class of Stock [Line Items]
Common Stock, Shares, Outstanding	156,074,200		156,074,200		155,718,825
General Partners' Capital Account, Units Outstanding (in units)	1,736,531		1,736,531
Limited Partners' Capital Account, Units Outstanding (in units)	154,337,669		154,337,669
Options exercised			206,377
Shares of Common Stock issued in connection with redemption of an equal number of OP Units (in shares)			118,290
Preferred Stock, Redemption Amount \| $	$ 193,623		$ 193,623
Preferred Stock Redemption Premium \| $			6,412	$ 0
ATM Program [Member]
Class of Stock [Line Items]
At The Market Stock Offering Program Aggregate Value Of Common Stock \| $		$ 600,000					$ 600,000
At Market Stock Offering Program Maximum Length Of Sale (in years) \| yr		3
Series B Cumulative Redeemable Preferred Stock / Unit [Member]
Class of Stock [Line Items]
Series B, Shares Outstanding (in shares)					80,000	80,000
Series B, Dividend Rate, Percentage					5.25%
Series B, Liquidation Preference Per Share (dollars per share) \| $ / shares					$ 2,500
Preferred Stock, Redemption Price Per Share \| $ / shares						$ 2,500
Preferred Stock Redemption Price Per Share, plus accrued and unpaid dividends \| $ / shares						$ 2,516.41
Preferred Stock, Redemption Amount \| $	201,300		201,300
Redeemable Preferred Stock Dividends \| $	$ 1,300
Preferred Stock Redemption Premium \| $			$ 6,400
Depositary shares of Series B Cumulative Redeemable Preferred [Member]
Class of Stock [Line Items]
Series B, Shares Outstanding (in shares)					8,000,000
Boston Properties Limited Partnership \| Series B Cumulative Redeemable Preferred Stock / Unit [Member]
Class of Stock [Line Items]
Series B, Shares Outstanding (in shares)					80,000
Series B, Liquidation Preference Per Share (dollars per share) \| $ / shares					$ 2,500