Borrowing Arrangements - Narrative (Details)			1 Months Ended	3 Months Ended										9 Months Ended		12 Months Ended
	Apr. 21, 2022 USD ($)	Feb. 16, 2021 USD ($)	May 31, 2019 USD ($)	Jun. 30, 2024	Dec. 31, 2023	Sep. 30, 2023	Jun. 30, 2023	Mar. 31, 2023	Dec. 31, 2022	Sep. 30, 2022 USD ($) $ / shares	Jun. 30, 2022	Mar. 31, 2022	Sep. 30, 2021 USD ($)	Sep. 30, 2022 USD ($) $ / shares	Sep. 30, 2021 USD ($)	Dec. 31, 2021 USD ($)	Nov. 30, 2018 USD ($)
Debt Instrument [Line Items]
Debt instrument, covenant compliance														As of September 30, 2022, the Company was in compliance with its debt covenants under the Amended Credit Agreement.
Long-term borrowings										$ 305,200,000				$ 305,200,000		$ 324,000,000.0
Redemptions of convertible debentures														0		0
Approximate redemption value of convertible debentures														1,100,000		1,100,000
Interest Rate Contract
Debt Instrument [Line Items]
Interest rate collar, term			3 years
Notional amount			$ 222,300,000
Derivative, cap interest rate			2.50%
Liability																700,000
Interest paid													$ 600,000	800,000	$ 1,800,000
Senior Credit Facility, Net of Discount
Debt Instrument [Line Items]
Long-term borrowings										$ 285,800,000				$ 285,800,000		$ 301,600,000
Weighted average interest rate										4.60%			3.60%	4.60%	3.60%
Convertible Subordinated Debt
Debt Instrument [Line Items]
Redemption price upon stated maturity (in dollars per share) | $ / shares														$ 19.18
Convertible debentures maturity per share | $ / shares										$ 25				$ 25
Amended Credit Agreement
Debt Instrument [Line Items]
Maximum borrowing capacity	$ 200,000,000.0	$ 600,000,000.0
Line of credit facility, expiration date	Apr. 21, 2027
Percentage principal installments	1.25%
Amended Credit Agreement | Scenario Forecast
Debt Instrument [Line Items]
Percentage principal installments				0.625%
Amended Credit Agreement | Revolving Credit Facility
Debt Instrument [Line Items]
Maximum borrowing capacity		400,000,000.0
Amended Credit Agreement | Letter of Credit Facility
Debt Instrument [Line Items]
Maximum borrowing capacity		100,000,000.0
Amended Credit Agreement | Term Loan Facility
Debt Instrument [Line Items]
Maximum borrowing capacity	$ 17,200,000	182,800,000															$ 200,000,000.0
Amended Credit Agreement | Senior Credit Facility, Net of Discount
Debt Instrument [Line Items]
Unrestricted cash and cash equivalents		$ 30,000,000.0
Minimum consideration amount consummated for fiscal quarter acquisition										$ 50,000,000.0				$ 50,000,000.0
Letters of credit outstanding										39,500,000				39,500,000
Long-term borrowings										$ 287,100,000				287,100,000
Fees and other closing cost														$ 2,500,000	$ 1,300,000
Amended Credit Agreement | Senior Credit Facility, Net of Discount | Minimum
Debt Instrument [Line Items]
Consolidated leverage ratio										1.0	1.0	1.0
Consolidated leverage ratio for fiscal quarter acquisition										1.0
Consolidated interest coverage ratio												1.0
Amended Credit Agreement | Senior Credit Facility, Net of Discount | Maximum
Debt Instrument [Line Items]
Consolidated leverage ratio										4.50	4.50	4.50
Consolidated leverage ratio for fiscal quarter acquisition										4.50
Consolidated interest coverage ratio												3.5
Amended Credit Agreement | Senior Credit Facility, Net of Discount | Scenario Forecast | Minimum
Debt Instrument [Line Items]
Consolidated leverage ratio					1.00	1.0	1.0	1.0	1.0
Amended Credit Agreement | Senior Credit Facility, Net of Discount | Scenario Forecast | Maximum
Debt Instrument [Line Items]
Consolidated leverage ratio					4.00	4.25	4.25	4.25	4.25
Amended Credit Agreement | Senior Credit Facility, Net of Discount | Base Rate Loans | Federal Funds
Debt Instrument [Line Items]
Interest rate margin on variable rate basis	0.50%
Amended Credit Agreement | Senior Credit Facility, Net of Discount | Base Rate Loans | SOFR
Debt Instrument [Line Items]
Interest rate margin on variable rate basis	1.00%
Floor interest rate	0.00%
Amended Credit Agreement | Senior Credit Facility, Net of Discount | LIBOR Loans
Debt Instrument [Line Items]
Period of total debt to EBITDA ratio		12 months
Senior Credit Facility | Senior Credit Facility, Net of Discount
Debt Instrument [Line Items]
Weighted average interest rate										4.90%			3.80%	4.90%	3.80%