Annual report pursuant to Section 13 and 15(d)

Derivative Financial Instruments - Additional Information (Detail)

v3.10.0.1
Derivative Financial Instruments - Additional Information (Detail)
12 Months Ended
Dec. 31, 2018
USD ($)
Instrument
Dec. 31, 2017
USD ($)
Dec. 31, 2016
USD ($)
Derivative [Line Items]      
Cash flow hedge ineffectiveness Ineffectiveness was de minimis in 2018, 2017, and 2016.    
Repayments of variable rate term notes   $ 225,000,000 $ 150,000,000
Effective portion of gain (loss) on derivatives net of reclassification to interest expense $ 712,000 13,888,000 (7,060,000)
Realized (gain) loss on derivatives net of accumulated other comprehensive loss to interest expense $ 593,000 13,185,000 5,044,000
Number of interest rate swaps held | Instrument 0    
Senior Term Note Due July 1, 2026 [Member]      
Derivative [Line Items]      
Settlement of forward starting swap agreements $ 9,200,000    
Amortized period on interest expense 10 years    
Interest Expense [Member]      
Derivative [Line Items]      
Realized (gain) loss on derivatives net of accumulated other comprehensive loss to interest expense $ (200,000) 12,300,000 $ 4,600,000
Interest Rate Swaps Settled in 2018 [Member]      
Derivative [Line Items]      
Effective portion of gain (loss) on derivatives net of reclassification to interest expense 0 0  
Derivative notional amount 100,000,000    
Realized (gain) loss on derivatives net of accumulated other comprehensive loss to interest expense $ 0    
Interest Rate Swaps Settled in 2018 [Member] | Interest Expense [Member]      
Derivative [Line Items]      
Settlement of terminated interest rate swap agreements   $ 9,600,000