Income Taxes - Foreign and Domestic Income Components (Details) - USD ($) $ in Thousands	3 Months Ended	12 Months Ended
Dec. 31, 2018	Dec. 31, 2017	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2017
Income Tax Disclosure [Abstract]
Domestic			$ (9,609)	$ 28,645	$ 29,598
Foreign			13,783	26,894	13,080
Income from continuing operations before income taxes	$ (4,718)	$ 19,709	$ 4,174	$ 55,539	$ 42,678

The portion of earnings or loss from continuing operations before income taxes that is attributable to domestic operations.

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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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The portion of earnings or loss from continuing operations before income taxes that is attributable to foreign operations, which is defined as Income or Loss generated from operations located outside the entity's country of domicile.

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