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Stock Option and Incentive Plan (Tables) | 12 Months Ended
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Dec. 31, 2018
Stock Option and Incentive Plan and Stock Purchase Plan [Abstract] |
Share-based Compensation, Stock Options, Activity [Table Text Block] | A summary of the status of Boston Properties, Inc.’s stock options as of December 31, 2018, 2017 and 2016 and changes during the years then ended are presented below:
|  | Shares |  | Weighted-Average Exercise Price
Outstanding at December 31, 2015 |  | 547,129 |  |  | $ | 96.38 |
Exercised |  | — |  |  | $ | — |
Outstanding at December 31, 2016 |  | 547,129 |  |  | $ | 96.38 |
Exercised |  | (6,688 | ) |  | $ | 99.15 |
Outstanding at December 31, 2017 |  | 540,441 |  |  | $ | 96.35 |
Exercised |  | — |  |  | $ | — |
Outstanding at December 31, 2018 |  | 540,441 |  |  | $ | 96.35 |
Schedule of Stock Options Outstanding [Table Text Block] | The following table summarizes information about Boston Properties, Inc.’s stock options outstanding at December 31, 2018:
Options Outstanding |  | Options Exercisable
Number Outstanding at 12/31/18 |  | Weighted-Average Remaining Contractual Life |  | Exercise Price |  | Number Exercisable at 12/31/18 |  | Exercise Price
118,502 |  |  | 2.1 years |  | $ | 86.86 |  |  | 118,502 |  |  | $ | 86.86 |
54,282 |  |  | 4.3 years |  | $ | 95.69 |  |  | 54,282 |  |  | $ | 95.69 |
202,030 |  |  | 4.1 years |  | $ | 98.46 |  |  | 202,030 |  |  | $ | 98.46 |
165,627 |  |  | 3.1 years |  | $ | 100.77 |  |  | 165,627 |  |  | $ | 100.77 |

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- Definition Tabular disclosure for stock option plans. Includes, but is not limited to, outstanding awards at beginning and end of year, grants, exercises, forfeitures, and weighted-average grant date fair value. + 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 (d) -URI http://asc.fasb.org/extlink&oid=96867065&loc=d3e5070-113901 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (e) -URI http://asc.fasb.org/extlink&oid=96867065&loc=d3e5070-113901 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (c)(1) -URI http://asc.fasb.org/extlink&oid=96867065&loc=d3e5070-113901 + Details
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