Fair Value Measurements and Interest Rate Swaps - Recurring Fair Value (Details) - USD ($) $ in Thousands	Sep. 30, 2021	Sep. 30, 2020
Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Unrealized gains on interest rate swaps	$ 5,488	$ 0
Unrealized losses on interest rate swaps	6,308	14,828
Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Contingent consideration liabilities	$ 983	$ 869

Fair value, before effects of master netting arrangements, of a financial liability or contract with one or more underlyings, notional amount or payment provision or both, and the contract can be net settled by means outside the contract or delivery of an asset. Includes liabilities elected not to be offset. Excludes liabilities not subject to a master netting arrangement.

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