XML 50 R48.htm IDEA: XBRL DOCUMENT v3.19.3.a.u2
Derivative Financial Instruments - Additional Information (Detail) - USD ($)
12 Months Ended
May 09, 2019
Oct. 17, 2018
Nov. 17, 2017
Jun. 24, 2016
Dec. 31, 2020
Dec. 31, 2019
Dec. 31, 2018
Dec. 31, 2017
Nov. 30, 2018
Jan. 04, 2018
Nov. 20, 2017
Apr. 17, 2017
Derivative Instruments Gain Loss [Line Items]                        
Derivative, strike rate for the interest rate swap contract       1.145%               1.1325%
Realized gains (losses) on interest rate hedges reclassified to earnings           $ 1,139,000 $ 1,372,000 $ (107,000)        
Unsecured Term Loan                        
Derivative Instruments Gain Loss [Line Items]                        
Secured credit facility borrowing capacity     $ 100,000,000               $ 100,000,000  
Cash Flow Hedge                        
Derivative Instruments Gain Loss [Line Items]                        
Derivative, notional amount           400,000,000 400,000,000          
Derivative, strike rate for the forward interest rate swap contract 2.176%                      
Cash Flow Hedge | Other Income (Expense)                        
Derivative Instruments Gain Loss [Line Items]                        
Recognition of hedge ineffectiveness               $ 94,000        
Interest Rate Swap                        
Derivative Instruments Gain Loss [Line Items]                        
Derivative, notional amount       $ 150,000,000                
Derivative, maturity date       Jun. 17, 2021                
Recognition of hedge ineffectiveness           0            
Interest Rate Swap | Cash Flow Hedge                        
Derivative Instruments Gain Loss [Line Items]                        
Derivative, notional amount           150,000,000 150,000,000          
Interest Rate Collar | Cash Flow Hedge                        
Derivative Instruments Gain Loss [Line Items]                        
Derivative, notional amount   $ 100,000,000 $ 100,000,000     $ 250,000,000 $ 250,000,000   $ 150,000,000      
Derivative, maturity date   Jan. 17, 2024 Nov. 17, 2024                  
Interest rate cap strike rate   2.50% 2.00%                  
Floor interest rate   2.25% 1.25%                  
Interest Rate Collar | Cash Flow Hedge | Designated                        
Derivative Instruments Gain Loss [Line Items]                        
Derivative, notional amount     $ 50,000,000                  
Interest Rate Collar | Cash Flow Hedge                        
Derivative Instruments Gain Loss [Line Items]                        
Derivative, notional amount     $ 50,000,000                  
Interest Rate Collar | Cash Flow Hedge | Designated                        
Derivative Instruments Gain Loss [Line Items]                        
Derivative, notional amount                   $ 50,000,000    
Forward Interest Rate Swap | Cash Flow Hedge                        
Derivative Instruments Gain Loss [Line Items]                        
Derivative, notional amount $ 150,000,000                      
Derivative, maturity date Jun. 17, 2026                      
Derivative, effective date Jun. 17, 2021                      
Interest Rate Swaps and Caps | Cash Flow Hedge | Scenario, Forecast                        
Derivative Instruments Gain Loss [Line Items]                        
Reclassified out of accumulated other comprehensive income to earnings, amount         $ 1,478,000