Stockholders' Equity / Partners' Capital Partners' Capital Changes in Issued and Outstanding Partners' Capital Units (Details) - shares	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Limited Partners' Capital Account [Line Items]
Units issued to Boston Properties, Inc. related to Common Stock issued in exchange for OP Units	83,136	495,637
Limited Partners' Ending Balance	152,736,142
General Partners' Ending Balance	1,722,336
Boston Properties Limited Partnership
Limited Partners' Capital Account [Line Items]
General Partners' Beginning Balance	1,719,540
Limited Partners Beginning Balance	152,605,746
Partners' Capital Beginning Balance	154,325,286	153,790,175	153,579,966
Units issued to Boston Properties, Inc. related to Common Stock issued under the Employee Stock Purchase Plan	6,268	6,317	5,695
Units issued to Boston Properties, Inc. related to Common Stock issued under the Stock Option and Incentive Plan, net	43,788	33,157	13,657
Units issued to Boston Properties, Inc. related to Common Stock issued in exchange for OP Units	83,136	495,637	190,857
Limited Partners' Ending Balance	152,736,142	152,605,746
Partners' Capital Ending Balance	154,458,478	154,325,286	153,790,175
General Partners' Ending Balance	1,722,336	1,719,540
Boston Properties Limited Partnership | General Partner [Member]
Limited Partners' Capital Account [Line Items]
General Partners' Beginning Balance	1,719,540	1,717,743	1,715,092
Units issued to Boston Properties, Inc. related to Common Stock issued under the Employee Stock Purchase Plan	132	21	72
Units issued to Boston Properties, Inc. related to Common Stock issued under the Stock Option and Incentive Plan, net	919	111	172
Units issued to Boston Properties, Inc. related to Common Stock issued in exchange for OP Units	1,745	1,665	2,407
General Partners' Ending Balance	1,722,336	1,719,540	1,717,743
Boston Properties Limited Partnership | Limited Partner [Member]
Limited Partners' Capital Account [Line Items]
Limited Partners Beginning Balance	152,605,746	152,072,432	151,864,874
Units issued to Boston Properties, Inc. related to Common Stock issued under the Employee Stock Purchase Plan	6,136	6,296	5,623
Units issued to Boston Properties, Inc. related to Common Stock issued under the Stock Option and Incentive Plan, net	42,869	33,046	13,485
Units issued to Boston Properties, Inc. related to Common Stock issued in exchange for OP Units	81,391	493,972	188,450
Limited Partners' Ending Balance	152,736,142	152,605,746	152,072,432