Business and summary of significant accounting policies - Cash, Goodwill and Long-lived Assets (Details) - USD ($) |
12 Months Ended | |||
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Jul. 01, 2018 |
Sep. 30, 2018 |
Sep. 30, 2017 |
Sep. 30, 2016 |
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| Property and Equipment | ||||
| Goodwill, impairment loss | $ 0 | $ 0 | ||
| Restricted cash | 7,300,000 | $ 13,500,000 | ||
| Impairment of long-lived assets held-for-use | $ 0 | $ 0 | $ 0 | |
| Buildings | Maximum | ||||
| Property and Equipment | ||||
| Estimated useful lives | 39 years | |||
| Office furniture and equipment. | Maximum | ||||
| Property and Equipment | ||||
| Estimated useful lives | 7 years | |||
| Software development costs. | Minimum | ||||
| Property and Equipment | ||||
| Estimated useful lives | 3 years | |||
| Software development costs. | Maximum | ||||
| Property and Equipment | ||||
| Estimated useful lives | 8 years | |||
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- Definition Amount of loss from the write-down of an asset representing the future economic benefits arising from other assets acquired in a business combination that are not individually identified and separately recognized. Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
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- Definition The aggregate amount of write-downs for impairments recognized during the period for long lived assets held for use (including those held for disposal by means other than sale). Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
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- Definition Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table. No definition available.
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- Definition Useful life of long lived, physical assets used in the normal conduct of business and not intended for resale, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days. Examples include, but not limited to, land, buildings, machinery and equipment, office equipment, furniture and fixtures, and computer equipment. No definition available.
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- Definition Amount of cash and cash equivalents restricted as to withdrawal or usage, classified as current. Cash includes, but is not limited to, currency on hand, demand deposits with banks or financial institutions, and other accounts with general characteristics of demand deposits. Cash equivalents include, but are not limited to, short-term, highly liquid investments that are both readily convertible to known amounts of cash and so near their maturity that they present insignificant risk of changes in value because of changes in interest rates. Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
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