Income Taxes- Summary of Income Tax Benefit and Effective Income Tax Rate (Details) - USD ($) $ in Thousands	3 Months Ended
Dec. 31, 2018	Dec. 31, 2017
Income Tax Disclosure [Abstract]
Loss before income taxes	$ (11,962)	$ (32,215)
Income tax (benefit)	$ (3,135)	$ (51,539)
Effective income tax rate	26.20%	106.10%

Amount of income (loss) from continuing operations, including income (loss) from equity method investments, before deduction of income tax expense (benefit), and income (loss) attributable to noncontrolling interest.

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