Strategic Investments - Additional Information (Details) $ in Thousands, $ in Millions	1 Months Ended		3 Months Ended		12 Months Ended			104 Months Ended
	Jun. 30, 2018 USD ($) shares	Jun. 30, 2018 AUD ($) shares	Mar. 31, 2019 USD ($)	Dec. 31, 2018 USD ($)	Sep. 30, 2020 USD ($) shares	Sep. 30, 2019 USD ($)	Sep. 30, 2018 USD ($)	Jun. 30, 2018 USD ($)
Schedule of Equity Method Investments [Line Items]
Payments to acquire equity method investment					$ 0	$ 0	$ 14,036
Income (loss) from equity method investments					(2,429)	(135)	5,529
Loss on deconsolidation					$ 300
Cash Converters International Limited
Schedule of Equity Method Investments [Line Items]
Number of common shares owned (in shares) | shares					214,183,714
Percentage of common shares owned					34.75%
Payments to acquire equity method investment								$ 96,100
Number of shares acquired (shares) | shares	57,631,230	57,631,230
Value of shares acquired	$ 14,000	$ 39.5
Percentage of ownership increase	3.00%	3.00%
Income (loss) from equity method investments					$ (2,100)	(100)	$ 5,500
Accumulated undistributed after-tax earnings included in consolidated retained earnings					$ 13,700
Other than temporary impairment, before taxes			$ 6,500	$ 13,300
Other than temporary impairment, net of taxes			$ 5,000	$ 10,300
Impairment of investment, not other-than-temporary						$ 6,200
Cash Converters International Limited | Underwritten Placement
Schedule of Equity Method Investments [Line Items]
Number of shares acquired (shares) | shares	123,300,000	123,300,000
Rich Data Corporation
Schedule of Equity Method Investments [Line Items]
Ownership percentage after dilution					0.1314