Fair Value Measurements - Fair Value by Major Security Type (Details) - USD ($) $ in Thousands	Dec. 31, 2024	Sep. 30, 2024
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Gross Unrealized Loss	$ (1)
Short-term Securities	5,146	$ 7,945
Long-term Securities	305	249
Fair Value, Recurring [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cost Basis	6,729	8,639
Gross Unrealized Gain	2	8
Gross Unrealized Loss	(1)	0
Fair Value	6,730	8,647
Cash Equivalents	1,279	453
Short-term Securities	5,146	7,945
Long-term Securities	305	249
Fair Value, Recurring [Member] | Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cost Basis	1,279	301
Gross Unrealized Gain	0	0
Gross Unrealized Loss	0	0
Fair Value	1,279	301
Cash Equivalents	1,279	301
Short-term Securities	0	0
Long-term Securities	0	0
Fair Value, Recurring [Member] | Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cost Basis	5,450	8,338
Gross Unrealized Gain	2	8
Gross Unrealized Loss	(1)	0
Fair Value	5,451	8,346
Cash Equivalents	0	152
Short-term Securities	5,146	7,945
Long-term Securities	305	249
Fair Value, Recurring [Member] | Level 2 [Member] | Certificates of Deposit [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cost Basis	253	401
Gross Unrealized Gain	0	0
Gross Unrealized Loss	0	0
Fair Value	253	401
Cash Equivalents	0	152
Short-term Securities	253
Long-term Securities	0	249
Fair Value, Recurring [Member] | Level 2 [Member] | U.S. Government Agency Bonds [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cost Basis	641	2,591
Gross Unrealized Gain	0	3
Gross Unrealized Loss	0	0
Fair Value	641	2,594
Cash Equivalents	0	0
Short-term Securities	641	2,594
Long-term Securities	0	0
Fair Value, Recurring [Member] | Level 2 [Member] | Municipal Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cost Basis	2,306	2,127
Gross Unrealized Gain	1	2
Gross Unrealized Loss	(1)	0
Fair Value	2,306	2,129
Cash Equivalents	0	0
Short-term Securities	2,001	2,129
Long-term Securities	305	0
Fair Value, Recurring [Member] | Level 2 [Member] | Corporate Bonds [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cost Basis	2,250	3,219
Gross Unrealized Gain	1	3
Gross Unrealized Loss	0	0
Fair Value	2,251	3,222
Cash Equivalents	0	0
Short-term Securities	2,251	3,222
Long-term Securities	$ 0	$ 0