Business segments - Revenue from External Customers by Geographic Areas (Details) - USD ($) $ in Thousands |
3 Months Ended | 12 Months Ended | |||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|
Sep. 30, 2019 |
Jun. 30, 2019 |
Mar. 31, 2019 |
Dec. 31, 2018 |
Sep. 30, 2018 |
Jun. 30, 2018 |
Mar. 31, 2018 |
Dec. 31, 2017 |
Sep. 30, 2019 |
Sep. 30, 2018 |
Sep. 30, 2017 |
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| Revenues and total long-lived assets | |||||||||||
| Revenue | $ 754,966 | $ 730,710 | $ 736,520 | $ 664,619 | $ 558,446 | $ 597,855 | $ 612,787 | $ 623,148 | $ 2,886,815 | $ 2,392,236 | $ 2,450,961 |
| United States | |||||||||||
| Revenues and total long-lived assets | |||||||||||
| Revenue | 2,287,685 | 1,692,823 | 1,765,661 | ||||||||
| United Kingdom | |||||||||||
| Revenues and total long-lived assets | |||||||||||
| Revenue | 293,695 | 347,026 | 346,342 | ||||||||
| Australia | |||||||||||
| Revenues and total long-lived assets | |||||||||||
| Revenue | 198,795 | 247,850 | 232,434 | ||||||||
| Rest of World | |||||||||||
| Revenues and total long-lived assets | |||||||||||
| Revenue | $ 106,640 | $ 104,537 | $ 106,524 | ||||||||
| X | ||||||||||
- Definition Amount, excluding tax collected from customer, of revenue from satisfaction of performance obligation by transferring promised good or service to customer. Tax collected from customer is tax assessed by governmental authority that is both imposed on and concurrent with specific revenue-producing transaction, including, but not limited to, sales, use, value added and excise. 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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