Real Estate Schedule of Real Estate Properties (Details) - USD ($) $ in Thousands		Dec. 31, 2018	Dec. 31, 2017
Real Estate Properties [Line Items]
Land		$ 5,072,568	$ 5,080,679
Land held for future development	[1]	200,498	204,925
Buildings and improvements		13,356,751	12,284,164
Tenant improvements		2,396,932	2,219,608
Furniture, fixtures and equipment		44,351	37,928
Construction in progress		578,796	1,269,338
Total		21,649,896	21,096,642
Less: accumulated depreciation		(4,897,777)	(4,589,634)
Total real estate		16,752,119	16,507,008
Boston Properties Limited Partnership
Real Estate Properties [Line Items]
Land		4,971,475	4,976,303
Land held for future development	[1]	200,498	204,925
Buildings and improvements		13,059,488	11,977,062
Tenant improvements		2,396,932	2,219,608
Furniture, fixtures and equipment		44,351	37,928
Construction in progress		578,796	1,269,338
Total		21,251,540	20,685,164
Less: accumulated depreciation		(4,800,475)	(4,496,959)
Total real estate		$ 16,451,065	$ 16,188,205

[1] Includes pre-development costs.