CONSOLIDATED STATEMENTS OF CASH FLOWS (Parenthetical) - USD ($) $ in Thousands	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2017
Reconciliation of cash, cash equivalents, and restricted cash to the consolidated balance sheets
Cash and cash equivalents	$ 301,642	$ 197,708	$ 101,622
Restricted cash included in prepaid expenses and other current assets	3,529
Total cash, cash equivalents and restricted cash shown in the consolidated statements of cash flows	$ 305,171	$ 197,708	$ 101,622
Restricted cash, location	us-gaap:PrepaidExpenseAndOtherAssetsCurrent	us-gaap:PrepaidExpenseAndOtherAssetsCurrent	us-gaap:PrepaidExpenseAndOtherAssetsCurrent