Commitments And Contingencies (Details) $ in Thousands	3 Months Ended
	Mar. 31, 2022 USD ($) ft²	Dec. 31, 2021 USD ($)
Commitments And Contingencies [Line Items]
Letter of credit and performance obligations	$ 26,400
Notes receivable, net	9,674	$ 9,641
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	$ 60,000
Annual Aggregate Limit of Earthquake Insurance Seattle	$ 60,000
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
Note receivable fixed interest rate	8.00%
Boston Properties Limited Partnership
Commitments And Contingencies [Line Items]
Notes receivable, net	$ 9,674	$ 9,641
Operating partnership guarantee to cover liabilities of IXP	20,000
767 Venture, LLC [Member]
Commitments And Contingencies [Line Items]
Maximum funding obligation	17,700
Property insurance program per occurrence limits	$ 1,625,000
325 Main Street
Commitments And Contingencies [Line Items]
Net Rentable Area (in sf) | ft²	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%
Future Office Building [Member] | 325 Main Street
Commitments And Contingencies [Line Items]
Net Rentable Area (in sf) | ft²	420,000
Future Retail Building [Member] | 325 Main Street
Commitments And Contingencies [Line Items]
Net Rentable Area (in sf) | ft²	41,000
Home Ownership Units [Member] | Future Residential Building [Member] | 325 Main Street
Commitments And Contingencies [Line Items]
Affordable Housing requirement	20.00%