Fair Value Measurements - Carrying Values and Estimated Fair Values of Other Financial Assets and Liabilities (Details) - USD ($) $ in Thousands	Sep. 30, 2022	Sep. 30, 2021
Carrying Amount
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Senior Notes and Term Loan	$ 911,170	$ 983,827
Junior Subordinated Notes	72,270	70,203
Total debt, net	983,440	1,054,030
Fair Value
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Senior Notes and Term Loan	753,338	1,046,965
Junior Subordinated Notes	72,270	70,203
Total debt, net	$ 825,608	$ 1,117,168