Quarterly report pursuant to Section 13 or 15(d)

Summary of Significant Accounting Policies - Derivative Financial Instruments (Details)

v3.7.0.1
Summary of Significant Accounting Policies - Derivative Financial Instruments (Details) - Interest rate swap instruments
$ in Thousands
 1 Months Ended
Jun. 30, 2017
USD ($)
Sep. 30, 2015
USD ($)
Oct. 31, 2012
USD ($)
swap
Jul. 31, 2011
USD ($)
Mar. 31, 2010
USD ($)
Sep. 30, 2013
USD ($)
Dec. 31, 2007
USD ($)
contract
Derivative [Line Items]              
Number of instruments held | contract             2
Interest Rate Swap Contract 1              
Derivative [Line Items]              
Initial notional amount of interest rate swaps             $ 13,081
Interest rate swaps, variable to fixed interest rates             5.40%
Interest Rate Swap Contract 2              
Derivative [Line Items]              
Initial notional amount of interest rate swaps             $ 3,256
Interest rate swaps, variable to fixed interest rates             5.30%
Interest Rate Swap Contract 3              
Derivative [Line Items]              
Initial notional amount of interest rate swaps         $ 27,900    
Interest rate swaps, variable to fixed interest rates         3.74%    
Term of interest rate swap contract         14 years    
Interest Rate Swap Contract 4              
Derivative [Line Items]              
Initial notional amount of interest rate swaps       $ 38,571      
Interest rate swaps, variable to fixed interest rates       1.965%      
Term of interest rate swap contract       5 years      
Interest Rate Swap Contract 5              
Derivative [Line Items]              
Number of instruments held | swap     2        
Initial notional amount of interest rate swaps     $ 16,750        
Interest rate swaps, variable to fixed interest rates     1.71%        
Term of interest rate swap contract     8 years        
Future increase in notional amount           $ 42,247  
Interest Rate Swap Contract 6              
Derivative [Line Items]              
Number of instruments held | swap     2        
Initial notional amount of interest rate swaps     $ 25,377        
Interest rate swaps, variable to fixed interest rates     3.70%        
Term of interest rate swap contract     8 years        
Interest Rate Swap Contract 7              
Derivative [Line Items]              
Initial notional amount of interest rate swaps   $ 20,746          
Interest rate swaps, variable to fixed interest rates   2.19%          
Term of interest rate swap contract   7 years          
Interest Rate Swap Contract 8              
Derivative [Line Items]              
Initial notional amount of interest rate swaps   $ 14,084          
Interest rate swaps, variable to fixed interest rates   3.26%          
Term of interest rate swap contract   15 years          
Interest Rate Swap Contract 9              
Derivative [Line Items]              
Initial notional amount of interest rate swaps $ 14,100            
Interest rate swaps, variable to fixed interest rates 2.29%            
Term of interest rate swap contract 10 years