Real Estate Schedule of Real Estate Properties (Details) - USD ($) $ in Thousands		Dec. 31, 2017	Dec. 31, 2016
Real Estate Properties [Line Items]
Land		$ 5,080,679	$ 4,879,020
Land held for future development	[1]	204,925	246,656
Buildings and improvements		12,284,164	11,890,626
Tenant improvements		2,219,608	2,060,315
Furniture, fixtures and equipment		37,928	32,687
Construction in progress		1,269,338	1,037,959
Total		21,096,642	20,147,263
Less: accumulated depreciation		(4,589,634)	(4,222,235)
Total real estate		16,507,008	15,925,028
Boston Properties Limited Partnership
Real Estate Properties [Line Items]
Land		4,976,303	4,774,460
Land held for future development	[1]	204,925	246,656
Buildings and improvements		11,977,062	11,581,795
Tenant improvements		2,219,608	2,060,315
Furniture, fixtures and equipment		37,928	32,687
Construction in progress		1,269,338	1,037,959
Total		20,685,164	19,733,872
Less: accumulated depreciation		(4,496,959)	(4,136,364)
Total real estate		$ 16,188,205	$ 15,597,508

[1] Includes pre-development costs.