Stock-Based Compensation (Non-Vested Options) (Details) shares in Thousands	6 Months Ended
	Mar. 31, 2025 $ / shares shares
Restricted Stock Units
Nonvested Number of Restricted Stock Units [Roll Forward]
Number of Restricted Stock Units, Beginning Balance \| shares	846
Number of Restricted Stock Units, Granted \| shares	428
Number of Restricted Stock Units, Vested \| shares	(249)
Number of Restricted Stock Units, Canceled \| shares	(34)
Number of Restricted Stock Units, Ending Balance \| shares	991
Nonvested Restricted Stock Units, Weighted Average Grant Date Fair Value per Common Share [Roll Forward]
Restricted Stock Units, Weighted Average Grant Date Fair Value per Common Share, Beginning Balance \| $ / shares	$ 30.15
Restricted Stock Units, Weighted Average Grant Date Fair Value per Common Share, Granted \| $ / shares	32.16
Restricted Stock Units, Weighted Average Grant Date Fair Value per Common Share, Vested \| $ / shares	27.33
Restricted Stock Units, Weighted Average Grant Date Fair Value per Common Share, Canceled \| $ / shares	30.63
Restricted Stock Units, Weighted Average Grant Date Fair Value per Common Share, Ending Balance \| $ / shares	$ 31.71
Performance Shares
Nonvested Number of Restricted Stock Units [Roll Forward]
Number of Restricted Stock Units, Beginning Balance \| shares	220
Number of Restricted Stock Units, Granted \| shares	162
Number of Restricted Stock Units, Vested \| shares	(54)
Number of Restricted Stock Units, Canceled \| shares	(4)
Number of Restricted Stock Units, Ending Balance \| shares	324
Nonvested Restricted Stock Units, Weighted Average Grant Date Fair Value per Common Share [Roll Forward]
Restricted Stock Units, Weighted Average Grant Date Fair Value per Common Share, Beginning Balance \| $ / shares	$ 30.55
Restricted Stock Units, Weighted Average Grant Date Fair Value per Common Share, Granted \| $ / shares	32.64
Restricted Stock Units, Weighted Average Grant Date Fair Value per Common Share, Vested \| $ / shares	30.57
Restricted Stock Units, Weighted Average Grant Date Fair Value per Common Share, Canceled \| $ / shares	19.78
Restricted Stock Units, Weighted Average Grant Date Fair Value per Common Share, Ending Balance \| $ / shares	$ 31.71

DIGI INTERNATIONAL INC 10-Q