Derivative Financial Instruments - Additional Information (Detail)	3 Months Ended		9 Months Ended
	Sep. 30, 2019 USD ($) Instrument	Sep. 30, 2018 USD ($)	Sep. 30, 2019 USD ($) Instrument	Sep. 30, 2018 USD ($)
Derivative [Line Items]
Gains or losses included in accumulated other comprehensive loss	$ 229,000	$ 100,000	$ 687,000	$ 483,000
Number of interest rate swaps held | Instrument	0		0
Realized loss on derivatives net of accumulated other comprehensive loss to interest expense	$ (229,000)	(54,000)	$ (687,000)	(363,000)
Interest Expense [Member]
Derivative [Line Items]
Realized loss on derivatives net of accumulated other comprehensive loss to interest expense		(200,000)		(300,000)
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 Rate Swaps Settled in 2018 [Member]
Derivative [Line Items]
Derivative notional amount		$ 100,000,000		$ 100,000,000
Gains or losses included in accumulated other comprehensive loss			$ 0