Real Estate Real Estate Properties Table (Details) - USD ($) $ in Thousands		Mar. 31, 2018	Dec. 31, 2017
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items]
Land		$ 5,105,376	$ 5,080,679
Land held for future development	[1]	204,506	204,925
Buildings and improvements		12,435,573	12,284,164
Tenant improvements		2,266,796	2,219,608
Furniture, fixtures and equipment		41,507	37,928
Construction in Progress		1,262,886	1,269,338
Total		21,316,644	21,096,642
Accumulated depreciation		(4,674,838)	(4,589,634)
Total real estate		16,641,806	16,507,008
Boston Properties Limited Partnership
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items]
Land		5,001,810	4,976,303
Land held for future development	[1]	204,506	204,925
Buildings and improvements		12,130,901	11,977,062
Tenant improvements		2,266,796	2,219,608
Furniture, fixtures and equipment		41,507	37,928
Construction in Progress		1,262,886	1,269,338
Total		20,908,406	20,685,164
Accumulated depreciation		(4,580,949)	(4,496,959)
Total real estate		$ 16,327,457	$ 16,188,205

[1] Includes pre-development costs.