Income Taxes - Additional Information (Details) - USD ($) $ in Thousands	3 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Income Tax Disclosure [Line Items]
Effective income tax rate	(34.30%)	19.30%
U.S. federal statutory rates	21.00%	21.00%
Income tax expense (benefit)	$ 3,002	$ 538
Netherlands
Income Tax Disclosure [Line Items]
Income tax expense (benefit)	$ (5,000)