XML 76 R58.htm IDEA: XBRL DOCUMENT v3.8.0.1
Investments in Partially Owned Entities (Summary of Investments) (Details) - USD ($)
$ in Thousands
3 Months Ended
Mar. 31, 2018
Dec. 31, 2017
Schedule Of Equity Method Investments    
Carrying amount of investments in partially owned entities $ 1,033,228 $ 1,056,829
Other liabilities    
Schedule Of Equity Method Investments    
Carrying amount of investments in partially owned entities $ (102,460) (101,368)
7 West 34th Street | Other liabilities    
Schedule Of Equity Method Investments    
Equity method ownership percentage 53.00%  
Carrying amount of investments in partially owned entities $ (47,582) (47,369)
Sale of ownership interest, percent 47.00%  
330 Madison Avenue | Other liabilities    
Schedule Of Equity Method Investments    
Carrying amount of investments in partially owned entities $ (54,878) (53,999)
Partially Owned Office Buildings    
Schedule Of Equity Method Investments    
Carrying amount of investments in partially owned entities $ 497,735 504,393
Alexanders Inc    
Schedule Of Equity Method Investments    
Equity method ownership percentage 32.40%  
Carrying amount of investments in partially owned entities $ 116,078 126,400
PREIT    
Schedule Of Equity Method Investments    
Equity method ownership percentage 8.00%  
Carrying amount of investments in partially owned entities $ 65,187 66,572
UE    
Schedule Of Equity Method Investments    
Equity method ownership percentage 4.50%  
Carrying amount of investments in partially owned entities $ 44,176 46,152
Other investments    
Schedule Of Equity Method Investments    
Carrying amount of investments in partially owned entities $ 310,052 $ 313,312