Investments in Unconsolidated Joint Ventures Narrative (Details) $ in Thousands				9 Months Ended
	Sep. 06, 2017 USD ($) ft²	Aug. 07, 2017 USD ($) ft² yr	Jul. 28, 2017 USD ($) ft² a Vehicles Buildings	Sep. 30, 2017 USD ($)		Sep. 30, 2016 USD ($)	Jul. 10, 2017	Dec. 31, 2016 USD ($)
Schedule of Equity Method Investments [Line Items]
Payments to Acquire Equity Method Investments				$ 89,874		$ 546,982
Proceeds from mortgage notes payable				2,300,000		0
Cash held in escrow				83,779				$ 63,174
Capital distributions from unconsolidated joint ventures				$ 251,000		0
Podium Developer LLC [Member]
Schedule of Equity Method Investments [Line Items]
Ownership Percentage	50.00%			50.00%
Net Rentable Area (in sf) | ft²	385,000
Colorado Center [Member]
Schedule of Equity Method Investments [Line Items]
Vehicles In Structured Parking | Vehicles			3,100
Ownership Percentage							50.00%
number of buildings | Buildings			6
Area of Land | a			15
Net Rentable Area (in sf) | ft²			1,118,000
7750 Wisconsin Avenue [Member]
Schedule of Equity Method Investments [Line Items]
Ownership Percentage		50.00%		50.00%	[1]
Net Rentable Area (in sf) | ft²		722,000
Term of Lease Signed (in years) | yr		20
Payments and improvementst to enter into an equity method investments		$ 20,800
Cash held in escrow		$ 25,000
Secured Debt [Member] | Colorado Center [Member]
Schedule of Equity Method Investments [Line Items]
Coupon/Stated Rate			3.56%
Proceeds from mortgage notes payable			$ 550,000
Capital distributions from unconsolidated joint ventures			502,000
Boston Properties Limited Partnership
Schedule of Equity Method Investments [Line Items]
Payments to Acquire Equity Method Investments				$ 89,874		546,982
Proceeds from mortgage notes payable				2,300,000		0
Cash held in escrow				83,779				$ 63,174
Capital distributions from unconsolidated joint ventures				$ 251,000		$ 0
Boston Properties Limited Partnership | Secured Debt [Member] | Colorado Center [Member]
Schedule of Equity Method Investments [Line Items]
Capital distributions from unconsolidated joint ventures			$ 251,000
Joint venture partner [Member] | 7750 Wisconsin Avenue [Member]
Schedule of Equity Method Investments [Line Items]
Ownership Percentage		50.00%
Contribution of Property		$ 72,000
Payments and improvementst to enter into an equity method investments		4,900
Capital distributions from unconsolidated joint ventures		11,000
Secured Debt [Member] | Podium Developer LLC [Member]
Schedule of Equity Method Investments [Line Items]
Construction Loan	$ 204,600
Coupon/Stated Rate	2.25%
Number of extensions	2
Extension Option (in years)	1
Colorado Center [Member] | Colorado Center [Member]
Schedule of Equity Method Investments [Line Items]
Ownership Percentage							0.20%
Payments to Acquire Equity Method Investments		$ 2,100

[1] The entity is a VIE (See Note 2).