Income Taxes - Deferred Tax Liabilities (Details) - USD ($) $ in Thousands	Sep. 30, 2019	Sep. 30, 2018
Deferred Tax Liabilities, Gross [Abstract]
Depreciation and intangible amortization	$ (57,634)	$ (19,476)
Deferred tax liabilities	$ (57,634)	$ (19,476)

Amount of deferred tax liability attributable to taxable temporary differences.

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Name:	us-gaap_DeferredIncomeTaxLiabilities
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant