Business and summary of significant accounting policies - New Accounting Policies (Details) - USD ($) $ / shares in Units, $ in Thousands |
12 Months Ended | ||
|---|---|---|---|
Sep. 30, 2017 |
Sep. 30, 2016 |
Sep. 30, 2015 |
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| Item Effected [Line Items] | |||
| Vesting of equity compensation | $ (6,569) | $ 0 | $ 0 |
| Increase in cash provided by operations | 337,200 | $ 180,026 | $ 206,217 |
| Accounting Standards Update 2016-09 | |||
| Item Effected [Line Items] | |||
| Increase (decrease) in income taxes | $ (6,600) | ||
| Increase in number of diluted weighted average shares | 90,000 | ||
| Increase in basic and diluted earnings per share | $ 0.10 | ||
| Increase in cash provided by operations | $ 6,600 | ||
| Unvested restricted stock units | Accounting Standards Update 2016-09 | |||
| Item Effected [Line Items] | |||
| Stock options exercised and RSUs vesting (in shares) | 500,000 | ||
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- Definition Earnings Per Share, Basic and Diluted, Increase (Decrease), Net No definition available.
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- Definition Number of share options (or share units) exercised or restricted stock unit releases during the current period. No definition available.
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- Definition Amount of the difference between reported income tax expense (benefit) and expected income tax expense (benefit) computed by applying the domestic federal statutory income tax rates to pretax income (loss) from continuing operations attributable to nondeductible equity-based compensation costs. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- Definition The increase (decrease) during the reporting period in the amounts payable to taxing authorities for taxes that are based on the reporting entity's earnings, net of amounts receivable from taxing authorities for refunds of overpayments or recoveries of income taxes, and in deferred and other tax liabilities and assets. No definition available.
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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 Amount of cash inflow (outflow) from operating activities, including discontinued operations. Operating activity cash flows include transactions, adjustments, and changes in value not defined as investing or financing activities. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- Definition The sum of dilutive potential common shares or units used in the calculation of the diluted per-share or per-unit computation. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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