Goodwill - Additional Information (Detail) - USD ($) $ in Thousands	Mar. 31, 2020	Sep. 30, 2019
Goodwill And Other Assets Disclosure [Abstract]
Goodwill and other intangible assets	$ 65,139	$ 64,077

Carrying amount of finite-lived intangible assets, indefinite-lived intangible assets and goodwill. Goodwill is an asset representing the future economic benefits arising from other assets acquired in a business combination that are not individually identified and separately recognized. Intangible assets are assets, not including financial assets, lacking physical substance.

No definition available.

Name:	us-gaap_IntangibleAssetsNetIncludingGoodwill
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant