Document And Entity Information - shares	6 Months Ended
	Jun. 30, 2015	Aug. 03, 2015
Document And Entity Information [Abstract]
Document Type	10-Q
Document Period End Date	Jun. 30, 2015
Document Fiscal Year Focus	2015
Document Fiscal Period Focus	Q2
Entity Registrant Name	BOSTON PROPERTIES INC
Amendment Flag	false
Entity Central Index Key	0001037540
Current Fiscal Year End Date	--12-31
Entity Filer Category	Large Accelerated Filer
Entity Common Stock, Shares Outstanding		153,573,619