Goodwill Intangible Assets and Other Long Term Assets - Additional Information (Detail) - USD ($) $ in Thousands	Sep. 30, 2019	Sep. 30, 2018
Schedule Of Goodwill And Other Assets [Line Items]
Goodwill and other intangible assets	$ 64,077	$ 27,491
Other long-term assets	7,125	5,632
long Term Deposits and Other Long Term Investments [Member]
Schedule Of Goodwill And Other Assets [Line Items]
Other long-term assets	$ 7,100	$ 5,600

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