Long-term Debt - Interest Expense (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Mar. 31, 2018	Mar. 31, 2017	Mar. 31, 2018	Mar. 31, 2017
Recourse to EZCORP | 2019 Convertible Notes
Debt Instrument [Line Items]
Contractual interest expense	$ 1.1	$ 1.3	$ 2.1	$ 2.5
Amortization of debt discount and deferred financing costs	2.4	2.7	5.0	5.5
Total interest expense	3.5	4.0	7.1	8.0
Line of Credit | 2024 Convertible Notes
Debt Instrument [Line Items]
Contractual interest expense	1.0	0.0	2.0	0.0
Amortization of debt discount and deferred financing costs	1.3	0.0	2.5	0.0
Total interest expense	$ 2.3	$ 0.0	$ 4.5	$ 0.0