Debt (Notes)	3 Months Ended
Mar. 31, 2018
Debt [Abstract]
Debt Disclosure [Text Block]	5. Debt Credit Facility On April 24, 2017, Boston Properties Limited Partnership amended and restated its unsecured revolving credit agreement (as amended and restated, the "2017 Credit Facility"). Among other things, the 2017 Credit Facility (1) increased the total commitment of the revolving line of credit (the "Revolving Facility") from $1.0 billion to $1.5 billion, (2) extended the maturity date from July 26, 2018 to April 24, 2022, (3) reduced the per annum variable interest rates, and (4) added a $500.0 million delayed draw term loan facility (the "Delayed Draw Facility") that permits Boston Properties Limited Partnership to draw until the first anniversary of the closing date (See Note 12). Based on Boston Properties Limited Partnership’s current credit rating, (1) the applicable Eurocurrency margins for the Revolving Facility and Delayed Draw Facility are 82.5 basis points and 90 basis points, respectively, and (2) the facility fee on the Revolving Facility commitment is 0.125% per annum. The Delayed Draw Facility has a fee on unused commitments equal to 0.15% per annum. As of March 31, 2018, Boston Properties Limited Partnership had $115.0 million of borrowings and outstanding letters of credit totaling approximately $1.6 million outstanding under the 2017 Credit Facility, with the ability to borrow approximately $1.9 billion.

Debt (Notes)

3 Months Ended

Mar. 31, 2018

5. Debt

Credit Facility

On April 24, 2017, Boston Properties Limited Partnership amended and restated its unsecured revolving credit agreement (as amended and restated, the "2017 Credit Facility"). Among other things, the 2017 Credit Facility (1) increased the total commitment of the revolving line of credit (the "Revolving Facility") from $1.0 billion to $1.5 billion, (2) extended the maturity date from July 26, 2018 to April 24, 2022, (3) reduced the per annum variable interest rates, and (4) added a $500.0 million delayed draw term loan facility (the "Delayed Draw Facility") that permits Boston Properties Limited Partnership to draw until the first anniversary of the closing date (See Note 12). Based on Boston Properties Limited Partnership’s current credit rating, (1) the applicable Eurocurrency margins for the Revolving Facility and Delayed Draw Facility are 82.5 basis points and 90 basis points, respectively, and (2) the facility fee on the Revolving Facility commitment is 0.125% per annum. The Delayed Draw Facility has a fee on unused commitments equal to 0.15% per annum.

As of March 31, 2018, Boston Properties Limited Partnership had $115.0 million of borrowings and outstanding letters of credit totaling approximately $1.6 million outstanding under the 2017 Credit Facility, with the ability to borrow approximately $1.9 billion.