Annual report pursuant to Section 13 and 15(d)

Commitments and Contingencies - Narrative (Details)

v3.8.0.1
Commitments and Contingencies - Narrative (Details) - USD ($)
$ in Thousands
12 Months Ended
Dec. 31, 2017
Dec. 31, 2016
Dec. 31, 2015
Loss Contingencies [Line Items]      
Operating Leases, Rent Expense $ 7,100 $ 7,000 $ 6,400
Commitments to complete construction of our ongoing capital projects and other capital expenditure requirement $ 9,400    
Minimum [Member]      
Loss Contingencies [Line Items]      
Percent of guaranty of completion and principal guaranty 5.00%    
Maximum [Member]      
Loss Contingencies [Line Items]      
Percent of guaranty of completion and principal guaranty 100.00%    
Debt [Member] | Mortgages [Member]      
Loss Contingencies [Line Items]      
Maximum amount of joint venture debt guaranteed by the Company $ 32,800    
Unconsolidated Properties [Member]      
Loss Contingencies [Line Items]      
Commitments to complete construction of our ongoing capital projects and other capital expenditure requirement 1,100    
Company's Share of Joint Venture Purchase Commitment Remaining Minimum Amount Committed $ 548