Real Estate Properties Table (Details) - USD ($) $ in Thousands		Mar. 31, 2019	Jan. 01, 2019	Dec. 31, 2018
Real estate
Land		$ 5,061,532		$ 5,072,568
Right of use assets - finance leases		187,292		0
Right of use assets - operating leases		151,166	$ 151,800	0
Land held for future development	[1]	258,221		200,498
Buildings and improvements		13,286,605		13,356,751
Tenant improvements		2,444,358		2,396,932
Furniture, fixtures and equipment		43,080		44,351
Construction in progress		647,469		578,796
Total		22,079,723		21,649,896
Accumulated depreciation		(4,962,959)		(4,897,777)
Total real estate		17,116,764		16,752,119
Boston Properties Limited Partnership
Real estate
Land		4,961,028		4,971,475
Right of use assets - finance leases		187,292		0
Right of use assets - operating leases		151,166		0
Land held for future development	[1]	258,221		200,498
Buildings and improvements		12,991,108		13,059,488
Tenant improvements		2,444,358		2,396,932
Furniture, fixtures and equipment		43,080		44,351
Construction in progress		647,469		578,796
Total		21,683,722		21,251,540
Accumulated depreciation		(4,864,334)		(4,800,475)
Total real estate		$ 16,819,388		$ 16,451,065

[1] Includes pre-development costs.