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- Definition

Square Footage Of Signed Lease.

+ References

No definition available.

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- Definition

Term of Lease Signed (in years)

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No definition available.

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- Definition

Area of land held.

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No definition available.

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- Definition

Amount of write-down of assets recognized in the income statement. Includes, but is not limited to, losses from tangible assets, intangible assets and goodwill.

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- Definition

Amount of operating income (loss) attributable to disposal group, including, but not limited to, discontinued operation.

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Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
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- Definition

Amount of lessee's right to use underlying asset under finance lease.

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Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
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-SubTopic 20
-Section 45
-Paragraph 1
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- Definition

This element represents the amount of gain (loss) on sale of properties during the reporting period gross of the applicable income taxes realized.

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Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
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-URI http://asc.fasb.org/extlink&oid=6875705&loc=d3e641549-123027

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- Definition

Term of lessee's finance lease, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents reported fact of one year, five months, and thirteen days.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
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-SubTopic 20
-Section 50
-Paragraph 3
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- Definition

Net rentable area for properties owned.

+ References

No definition available.

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- Definition

Cash received from the sale of real estate that is held for investment, that is, it is part of an investing activity during the period.

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-Publisher FASB
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-SubTopic 10
-Section 45
-Paragraph 12
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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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Real Estate Narrative (Details) $ in Thousands			1 Months Ended	3 Months Ended		12 Months Ended
Real Estate Narrative (Details) $ in Thousands	Feb. 14, 2019 ft² yr	Jan. 24, 2019 USD ($) ft² a	Jan. 23, 2019 USD ($)	Mar. 31, 2019 USD ($)	Mar. 31, 2018 USD ($)	Dec. 31, 2018 USD ($)	Apr. 18, 2019 USD ($) ft²	Jan. 10, 2019 USD ($) ft²
Real Estate [Line Items]
Right of use assets - finance leases				$ 187,292		$ 0
Proceeds from sales of real estate				20,019	$ 116,120
Gains (loss) on sales of real estate				905	(96,397)
Boston Properties Limited Partnership
Real Estate [Line Items]
Right of use assets - finance leases				187,292		0
Proceeds from sales of real estate				20,019	116,120
Gains (loss) on sales of real estate				905	(98,907)
325 Main Street [Member]
Real Estate [Line Items]
Net Rentable Area (in sf) \| ft²	115,000
Platform 16 [Member]
Real Estate [Line Items]
Net Rentable Area (in sf) \| ft²		1,100,000
Finance Lease fixed purchase price		$ 134,800
Right of use assets - finance leases		$ 122,600
Lessee, Finance Lease, Term of Contract		65 years
Area of Land \| a		5.6
Carnegie Center [Member]
Real Estate [Line Items]
Net Rentable Area (in sf) \| ft²								1,700,000
Aggregate purchase price								$ 51,500
Deferred purchase price								$ 8,600
One Tower Center [Member]
Real Estate [Line Items]
Impairment loss				24,000
One Tower Center [Member] \| Boston Properties Limited Partnership
Real Estate [Line Items]
Impairment loss				22,300
2600 Tower Oaks Boulevard [Member]
Real Estate [Line Items]
Net Rentable Area (in sf) \| ft²		179,000
Gross Sale Price		$ 22,700
Proceeds from sales of real estate		$ 21,400
Net income (loss)			$ (200)		$ (200)
Gains (loss) on sales of real estate				$ 600
Impairment loss						3,100
2600 Tower Oaks Boulevard [Member] \| Boston Properties Limited Partnership
Real Estate [Line Items]
Impairment loss						$ 1,500
Future Office Building [Member] \| 325 Main Street [Member]
Real Estate [Line Items]
Net Rentable Area (in sf) \| ft²	400,000
Square Footage Of Signed Lease \| ft²	362,000
Term of Lease Signed (in years) \| yr	15
Future Retail Building [Member] \| 325 Main Street [Member]
Real Estate [Line Items]
Net Rentable Area (in sf) \| ft²	38,000
Subsequent Event [Member] \| One Tower Center [Member]
Real Estate [Line Items]
Net Rentable Area (in sf) \| ft²							410,000
Gross Sale Price							$ 38,000