v3.3.1.900
Basis of Presentation and Significant Accounting Policies (Partially Owned Entities and Variable Interest Entities (Details)
$ in Thousands
3 Months Ended 12 Months Ended
Dec. 31, 2014
USD ($)
property
Dec. 31, 2015
USD ($)
building
Dec. 31, 2014
USD ($)
property
Dec. 31, 2013
USD ($)
Variable Interest Entity [Line Items]        
Number of real estate properties 5 2 5  
VIE Asset Amount $ 219,600 $ 203,300 $ 219,600  
Variable Interest Entity, Consolidated, Carrying Amount, Liabilities 23,400 28,800 23,400  
Noncontrolling interest in consolidated subsidiary 5,862 6,520 5,862  
Proceeds from Sale of Real Estate Held-for-investment   319,639 427,544 $ 21,178
Real Estate Investment [Member]        
Variable Interest Entity [Line Items]        
VIE Asset Amount 211,800 $ 187,300 211,800  
Washington        
Variable Interest Entity [Line Items]        
Number of real estate properties | building   12    
Restricted cash [Member]        
Variable Interest Entity [Line Items]        
Proceeds from Sale of Real Estate Held-for-investment $ 59,200   59,200  
Undeveloped Land [Member]        
Variable Interest Entity [Line Items]        
Business acquisition costs capitalized   $ 1,100 $ 4,500 $ 2,300