Common Stock Weighted Average Price.

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- Definition

Employee and director payment per share

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- Definition

LTIP units issued

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- Definition

MYLTIP units issued

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- Definition

Number Of Days Used In Calculation, Average Closing Prices Of Common Stock

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- Definition

Payment Award Discount From Market Price Based on Ten Business Day Average

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- Definition

Value Of LTIP Units Issued.

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- Definition

Vesting period for grants of restricted stock and LTIP Units made in and after November 2006.

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- Definition

Weighted Average Per Unit Fair Value

+ References

No definition available.

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- Definition

Represents the expense recognized during the period arising from equity-based compensation arrangements (for example, shares of stock, unit, stock options or other equity instruments) with employees, directors and certain consultants qualifying for treatment as employees.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SAB TOPIC 14.F)
-URI http://asc.fasb.org/extlink&oid=27013229&loc=d3e301413-122809

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 50
-Paragraph 1
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=6415400&loc=d3e5047-113901

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-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (h)(1)(i)
-URI http://asc.fasb.org/extlink&oid=6415400&loc=d3e5070-113901

Reference 4: http://www.xbrl.org/2003/role/presentationRef
-Publisher SEC
-Name Staff Accounting Bulletin (SAB)
-Number Topic 14
-Section F

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- Definition

Total number of common shares of an entity that have been sold or granted to shareholders (includes common shares that were issued, repurchased and remain in the treasury). These shares represent capital invested by the firm's shareholders and owners, and may be all or only a portion of the number of shares authorized. Shares issued include shares outstanding and shares held in the treasury.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02.29)
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher SEC
-Name Regulation S-X (SX)
-Number 210
-Section 02
-Paragraph 30
-Article 5

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- Definition

Aggregate par or stated value of issued nonredeemable common stock (or common stock redeemable solely at the option of the issuer). This item includes treasury stock repurchased by the entity. Note: elements for number of nonredeemable common shares, par value and other disclosure concepts are in another section within stockholders' equity.

+ References

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- Definition

Unrecognized cost of unvested share-based compensation awards.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (i)
-URI http://asc.fasb.org/extlink&oid=6415400&loc=d3e5070-113901

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- Definition

Weighted average period over which unrecognized compensation is expected to be recognized for equity-based compensation plans, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

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- Definition

The estimated measure of the percentage by which a share price is expected to fluctuate during a period. Volatility also may be defined as a probability-weighted measure of the dispersion of returns about the mean. The volatility of a share price is the standard deviation of the continuously compounded rates of return on the share over a specified period. That is the same as the standard deviation of the differences in the natural logarithms of the stock prices plus dividends, if any, over the period.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (f)(2)(ii)
-URI http://asc.fasb.org/extlink&oid=6415400&loc=d3e5070-113901

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- Definition

The risk-free interest rate assumption that is used in valuing an option on its own shares.

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Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
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-Paragraph 2
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- Definition

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.

+ References

No definition available.

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- Definition

The maximum number of shares (or other type of equity) originally approved (usually by shareholders and board of directors), net of any subsequent amendments and adjustments, for awards under the equity-based compensation plan. As stock or unit options and equity instruments other than options are awarded to participants, the shares or units remain authorized and become reserved for issuance under outstanding awards (not necessarily vested).

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (a)(3)
-URI http://asc.fasb.org/extlink&oid=6415400&loc=d3e5070-113901

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- Definition

The weighted-average price as of the balance sheet date at which grantees can acquire the shares reserved for issuance on vested portions of options outstanding and currently exercisable under the stock option plan.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (c)(1)(iii)
-URI http://asc.fasb.org/extlink&oid=6415400&loc=d3e5070-113901

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- Definition

Amount by which the current fair value of the underlying stock exceeds the exercise price of options outstanding.

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- Definition

The weighted average of per share prices paid for shares purchased on the open market for issuance to employees under the plan.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 50
-Paragraph 2
-URI http://asc.fasb.org/extlink&oid=6415400&loc=d3e5070-113901

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-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 50
-Paragraph 1
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=6415400&loc=d3e5047-113901

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- Definition

Number of share instruments newly issued under a share-based compensation plan.

+ References

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- Definition

Expected term of share-based compensation awards, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SAB TOPIC 14.D.2)
-URI http://asc.fasb.org/extlink&oid=27013229&loc=d3e301413-122809

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-Name Accounting Standards Codification
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-URI http://asc.fasb.org/extlink&oid=6415400&loc=d3e5070-113901

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-Publisher SEC
-Name Staff Accounting Bulletin (SAB)
-Number Topic 14
-Section D
-Subsection 2

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Stock Option and Incentive Plan (Restricted Stock) (Narrative) (Details) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2016 USD ($) VestingInstallments d $ / shares shares	Dec. 31, 2015 USD ($) $ / shares shares	Dec. 31, 2014 USD ($) $ / shares shares	May 17, 2016 shares	Jan. 01, 2015 shares	May 20, 2014 shares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares issued	153,869,075	153,658,866		1,507		7,542
Stock-based compensation associated with restricted stock, non-qualified options, LTIP Units, 2012 OPP Units, and 2013-2016 MYLTIP Units \| $	$ 30,600	$ 26,900	$ 26,000
Value of shares of common stock \| $	1,538	$ 1,536
Exercisable, Weighted Average Exercise Price \| $ / shares		$ 96.10	$ 96.91
Total intrinsic value of the outstanding and exercisable stock options \| $	$ 15,200
Restricted Stock [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares issued	22,067	34,150	23,968
Employee and director payment per share (in dollars per share) \| $ / shares	$ 0.01
Value of shares of common stock \| $	$ 2,500	$ 4,800	$ 2,600
Employee's weighted average cost per share (in dollars per share) \| $ / shares	$ 113.51	$ 140.88	$ 109.27
LTIP Units [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
LTIP units issued (in shares)			127,094
Value of LTIP units issued \| $	$ 15,400	$ 13,500	$ 12,800
Per unit fair value weighted-average (in dollars per share) \| $ / shares	$ 103.83	$ 128.94	$ 100.61
Expected life assumed to calculate per unit fair value per LTIP unit (years)	5 years 8 months 12 days	5 years 8 months 12 days	5 years 8 months 12 days
Risk-free rate	1.61%	1.47%	1.84%
Expected price volatility	33.00%	26.00%	27.00%
LTIPs And Restricted Stock [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting annual installments \| VestingInstallments	4
LTIPS snd Restricted Stock[Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Unrecognized compensation expenses \| $	$ 19,200
MYLTIP Units [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Unrecognized compensation expenses \| $	$ 19,600
Weighted-average period (years)	2 years 3 months 18 days
LTIPs, OPP and MYLTIP Awards [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Employee and director payment per share (in dollars per share) \| $ / shares	$ 0.25
MYLTIP 2014
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
MYLTIP units issued			485,459
MYLTIP 2015 [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
MYLTIP units issued		375,000
MYLTIP 2016 [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
MYLTIP units issued	475,004
Non-Qualified Employee Stock Purchase Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Maximum Common Stock available for issuance	250,000
Employee Common Stock options, percent of average closing price	85.00%
Number Of Days Used In Calculation, Average Closing Prices Of Common Stock \| d	10
Shares issued	5,695	6,199	6,964
Shares issued, weighted-average purchase price per share \| $ / shares	$ 109.27	$ 108.73	$ 93.37
Board of Directors Chairman [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation associated with restricted stock, non-qualified options, LTIP Units, 2012 OPP Units, and 2013-2016 MYLTIP Units \| $			$ 2,500
Boston Properties Limited Partnership \| LTIP Units [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
LTIP units issued (in shares)	147,872	190,563
Boston Properties Limited Partnership \| Non-executive Chairman of the Board of Directors [Member] \| LTIP Units [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
LTIP units issued (in shares)					85,962