Financial Derivatives - Additional Information (Detail)				12 Months Ended
	Sep. 11, 2019 USD ($) Agreement	Mar. 31, 2017 USD ($)	Mar. 28, 2013 USD ($)	Sep. 30, 2019 USD ($)	Oct. 01, 2015 USD ($)
Derivative [Line Items]
Number of interest rate swap agreements | Agreement	2
Derivative, notional amount			$ 213,800,000
Derivative amortized amount			$ 2,800,000
Derivative, fair value, net					$ 2,400,000
Unrealized gain (loss) on derivatives		$ 2,400,000
5-Year Swap [Member]
Derivative [Line Items]
Derivative, notional amount	$ 250,000,000
Term of derivative agreement	5 years
Derivative, maturity date	Aug. 30, 2024
Derivative, fixed interest rate	1.49%
Derivative fair value, net of tax				$ 1,100,000
3-Year Swap [Member]
Derivative [Line Items]
Derivative, notional amount	$ 250,000,000
Term of derivative agreement	3 years
Derivative, maturity date	Aug. 30, 2022
Derivative, fixed interest rate	1.50%
Derivative fair value, net of tax				$ 500,000
Interest Rate Swap Fixed Rate of 1.38% [Member]
Derivative [Line Items]
Derivative, maturity date			Mar. 31, 2017
Derivative, fixed interest rate			1.38%
Derivative amortization frequency				quarter