Supplemental Disclosure of Cash Flow Information - Schedule of Supplemental Disclosure of Cash Flow Information (Detail) - USD ($) $ in Thousands	3 Months Ended
Dec. 31, 2020	Dec. 31, 2019
Cash paid during the period for:
Income taxes, net	$ 3,612	$ 4,750
Interest	$ 2,207	$ 3,126

Amount of cash paid for interest, excluding capitalized interest, classified as operating activity. Includes, but is not limited to, payment to settle zero-coupon bond for accreted interest of debt discount and debt instrument with insignificant coupon interest rate in relation to effective interest rate of borrowing attributable to accreted interest of debt discount.

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 50
-Paragraph 2
-URI http://asc.fasb.org/extlink&oid=121583591&loc=d3e4297-108586

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 17
-Subparagraph (d)
-URI http://asc.fasb.org/extlink&oid=121586364&loc=d3e3367-108585

Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 25
-Subparagraph (e)
-URI http://asc.fasb.org/extlink&oid=121586364&loc=d3e3536-108585

Name:	us-gaap_InterestPaidNet
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration