XML 16 R1.htm IDEA: XBRL DOCUMENT v3.10.0.1
Document And Entity Information - shares
 9 Months Ended
Sep. 30, 2018
Nov. 02, 2018
Entity Information [Line Items]    
Document Type 10-Q  
Document Period End Date Sep. 30, 2018  
Document Fiscal Year Focus 2018  
Document Fiscal Period Focus Q3  
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   154,440,500
Boston Properties Limited Partnership    
Entity Information [Line Items]    
Document Type 10-Q  
Document Period End Date Sep. 30, 2018  
Document Fiscal Year Focus 2018  
Document Fiscal Period Focus Q3  
Entity Registrant Name BOSTON PROPERTIES LTD PARTNERSHIP  
Amendment Flag false  
Entity Central Index Key 0001043121  
Current Fiscal Year End Date --12-31  
Entity Filer Category Non-accelerated Filer  
Entity Common Stock, Shares Outstanding   0