Annual report pursuant to Section 13 and 15(d)

Summary of Significant Accounting Policies (Details 2)

v3.6.0.2
Summary of Significant Accounting Policies (Details 2) - USD ($)
$ in Thousands
 12 Months Ended
Dec. 31, 2016
Dec. 31, 2015
Dec. 31, 2014
Accounting Policies [Abstract]      
Minimum adjusted taxable income to be distributed to shareholders to qualify as a REIT (as a percent) 90.00%    
Subsequent period during which entity would be disqualified as a REIT if during any tax year entity fails to qualify as a REIT (in years) 4 years    
Change in Accounting Estimate [Line Items]      
Approximate amount by which basis of assets and liabilities for tax reporting purposes is higher than amount reported on consolidated balance sheet $ 9,000    
Deferred lease related compensation costs 1,100 $ 1,200 $ 1,300
Future minimum payments due $ 91,249    
Common Shares [Member]      
Change in Accounting Estimate [Line Items]      
Ordinary income (as a percent) 48.00% 38.30% 64.50%
Long-term capital gain (as a percent) 0.00% 61.70% 6.50%
Return of capital (as a percent) 52.00% 0.00% 29.00%
Preferred Shares [Member]      
Change in Accounting Estimate [Line Items]      
Ordinary income (as a percent) 100.00% 38.30% 90.90%
Long-term capital gain (as a percent) 0.00% 61.70% 9.10%
Return of capital (as a percent) 0.00% 0.00% 0.00%
Ground Leases [Member]      
Change in Accounting Estimate [Line Items]      
Future minimum payments due $ 90,900    
Accounting Standards Update 2014-09 [Member]      
Change in Accounting Estimate [Line Items]      
Effect of change on net income $ 18,000