Annual report pursuant to Section 13 and 15(d)

Interest Rate Derivatives (Details)

v3.8.0.1
Interest Rate Derivatives (Details) - USD ($)
$ in Thousands
 12 Months Ended
May 01, 2017
Dec. 31, 2017
Dec. 31, 2016
Dec. 31, 2015
Fair value of interest rate derivatives and balance sheet classification        
Interest rate swaps designated as cash flow hedges   $ 3,073 $ 158  
Effect of interest rate derivatives on consolidated statements of operations and comprehensive income        
Unrealized gain (loss) recognized in AOCL (effective portion)   684 (2,915) $ (4,739)
Interest rate swaps        
Effect of interest rate derivatives on consolidated statements of operations and comprehensive income        
Unrealized gain (loss) recognized in AOCL (effective portion)   684 (2,915) (4,739)
Approximate amount of losses to be reclassified from AOCL to interest expense over the next 12 months   460    
Interest rate swaps | Interest expense [Member]        
Effect of interest rate derivatives on consolidated statements of operations and comprehensive income        
Loss reclassified from AOCL into interest expense (effective portion)   (3,216) (4,230) (3,599)
Gain (loss) on derivatives recognized in interest expense (ineffective portion)   323 378 (386)
Loss reclassified from AOCL into interest expense (ineffective portion)   (88) 0 $ 0
Interest rate swaps | Prepaid expenses and other assets [Member]        
Fair value of interest rate derivatives and balance sheet classification        
Interest rate swaps designated as cash flow hedges   3,073 158  
Interest rate swaps | Other liabilities [Member]        
Fair value of interest rate derivatives and balance sheet classification        
Interest rate swaps designated as cash flow hedges   0 (1,572)  
Designated [Member]        
Fair values of interest rate swap derivatives        
Fair value of interest rate swaps   3,073 (1,414)  
Designated [Member] | Interest rate swap, effective date September 1, 2015, swap two [Member]        
Fair values of interest rate swap derivatives        
Notional Amount   $ 100,000    
Fixed Rate (as a percent)   1.73%    
Fair value of interest rate swaps   $ 252 (848)  
Designated [Member] | Interest rate swap, effective October 13, 2015 [Member]        
Fair values of interest rate swap derivatives        
Notional Amount   $ 13,217    
Fixed Rate (as a percent)   1.39%    
Fair value of interest rate swaps   $ 213 100  
Notional amount after scheduled amortization   12,100    
Designated [Member] | Interest rate swap, effective September 1, 2016, swap one [Member]        
Fair values of interest rate swap derivatives        
Notional Amount   $ 100,000    
Fixed Rate (as a percent)   1.9013%    
Fair value of interest rate swaps   $ 1,046 (23)  
Designated [Member] | Interest rate swap, effective September 1, 2016, swap two [Member]        
Fair values of interest rate swap derivatives        
Notional Amount   $ 100,000    
Fixed Rate (as a percent)   1.905%    
Fair value of interest rate swaps   $ 1,051 48  
Designated [Member] | Interest rate swap, effective September 1, 2016, swap three [Member]        
Fair values of interest rate swap derivatives        
Notional Amount   $ 50,000    
Fixed Rate (as a percent)   1.9079%    
Fair value of interest rate swaps   $ 511 10  
Designated [Member] | Interest rate swap, effective date September 1, 2015, swap one [Member]        
Fair values of interest rate swap derivatives        
Notional Amount   $ 100,000    
Fixed Rate (as a percent)   1.673%    
Fair value of interest rate swaps   $ 0 $ (701)  
Interest rate swap cash settled $ 460