Commitments And Contingencies (Details) $ in Thousands		9 Months Ended
	Jun. 27, 2022 USD ($)	Sep. 30, 2022 USD ($) ft²	Sep. 30, 2021 USD ($)	Jun. 29, 2022 ft²	Jun. 26, 2022 USD ($)	Dec. 31, 2021 USD ($)	May 09, 2019 ft²
Commitments And Contingencies [Line Items]
Letter of credit and performance obligations		$ 26,500
Notes receivable, net		0				$ 9,641
Proceeds from note receivable		10,000	$ 0
Property insurance program per occurrence limits		1,000,000
Per occurrence limit for NBCR Coverage		1,000,000
Value of program trigger		$ 200,000
Coinsurance of program trigger		20.00%
Program trigger deductible		20.00%
Per occurrence limit of the earthquake insurance which covers San Francisco and Los Angeles regions		$ 330,000
Annual aggregate limit of the earthquake insurance which covers San Francisco and Los Angeles regions		330,000
Amount of earthquake insurance provided by IXP, LLC as direct insurer San Francisco and Los Angeles		$ 30,000
Deductible in insurance as a percentage of the value of the affected property, San Francisco and Los Angeles		3.00%
Per Occurrence Limit of Earthquake Insurance Seattle		$ 110,000
Annual Aggregate Limit of Earthquake Insurance Seattle		$ 110,000
Earthquake Deductible Insurance Percentage of Value of the Affected Property Seattle		2.00%
Affiliate of Bernstein Companies [Member]
Commitments And Contingencies [Line Items]
Notes receivable, net					$ 10,000
Proceeds from note receivable	$ 10,000
Note receivable fixed interest rate					8.00%
Proceeds from Interest Received	$ 1,600
Boston Properties Limited Partnership
Commitments And Contingencies [Line Items]
Notes receivable, net		$ 0				$ 9,641
Proceeds from note receivable		10,000	$ 0
Operating partnership guarantee to cover liabilities of IXP		20,000
767 Venture, LLC [Member]
Commitments And Contingencies [Line Items]
Maximum funding obligation		14,900
Property insurance program per occurrence limits		1,625,000
325 Main Street
Commitments And Contingencies [Line Items]
Net Rentable Area (in sf) | ft²				414,000			115,000
601 Lexington Avenue
Commitments And Contingencies [Line Items]
Coverage For Acts Of Terrorism Under TRIA Covered in Excess of Amount Covered by IXP		1,350,000
Coverage For Acts Of Terrorism Under TRIA Covered in Excess of Amount Covered by IXP - Property and Terrorism		750,000
Coverage For Acts Of Terrorism Under TRIA Covered in Excess of Amount Covered by IXP - Terrorism		600,000
Sum of Coverage Covered by IXP and Excess Coverage for Property and Terrorism		$ 1,750,000
Future Residential Building [Member] | 325 Main Street
Commitments And Contingencies [Line Items]
Net Rentable Area (in sf) | ft²		200,000
Affordable Housing requirement		25.00%
Home Ownership Units [Member] | Future Residential Building [Member] | 325 Main Street
Commitments And Contingencies [Line Items]
Affordable Housing requirement		20.00%