XML 16 R1.htm IDEA: XBRL DOCUMENT v3.10.0.1
Document and Entity Information - shares
 6 Months Ended
Jun. 30, 2018
Aug. 07, 2018
Document Information [Line Items]    
Entity Registrant Name SL GREEN REALTY CORP  
Entity Central Index Key 0001040971  
Current Fiscal Year End Date --12-31  
Entity Filer Category Large Accelerated Filer  
Document Type 10-Q  
Document Period End Date Jun. 30, 2018  
Document Fiscal Year Focus 2018  
Document Fiscal Period Focus (Q1,Q2,Q3,FY) Q2  
Amendment Flag false  
Entity Common Stock, Shares Outstanding   86,566,698
SL Green Operating Partnership    
Document Information [Line Items]    
Entity Registrant Name SL GREEN OPERATING PARTNERSHIP, LP.  
Entity Central Index Key 0001492869  
Current Fiscal Year End Date --12-31  
Entity Filer Category Non-accelerated Filer  
Document Type 10-Q  
Document Period End Date Jun. 30, 2018  
Document Fiscal Year Focus 2018  
Document Fiscal Period Focus (Q1,Q2,Q3,FY) Q2  
Amendment Flag false  
Entity Common Stock, Shares Outstanding   1,468,438