Significant Accounting Policies - Summary of Contract Liabilities (Details) - USD ($) $ in Thousands	Sep. 30, 2019	Sep. 30, 2018
Contract With Customer Liability [Line Items]
Total liability	$ 12,866	$ 5,309
Gift Cards | Accrued Liabilities
Contract With Customer Liability [Line Items]
Total liability	4,558	4,144
Rewards Loyalty Program | Accrued Liabilities
Contract With Customer Liability [Line Items]
Total liability	$ 8,308	$ 1,165