Income Taxes (Net Discrete Impact of Tax Act) (Details) $ in Thousands	3 Months Ended
	Dec. 31, 2017 USD ($)
Income Taxes
Transition Tax	$ 26,000
Impact on U.S. deferred tax assets and liabilities	(16,260)
Net changes in deferred tax liability associated with anticipated repatriation taxes	5,038
Net discrete impacts of the enactment of the Tax Act	$ 14,778