Income Taxes (Details) - USD ($) $ in Thousands		3 Months Ended
	Dec. 22, 2017	Dec. 31, 2017	Dec. 31, 2016
Income Taxes
Number of years rate reduction will be phased in	2 years
Blended federal statutory income tax rate (as a percent)	24.50%
Enacted federal statutory income tax rate for next fiscal years (as a percent)	21.00%	21.00%
Income tax benefit		$ 500,641	$ 18,288
Effective income tax rate (as a percent)		50064100.00%	34.60%
Income tax benefit relating to re-measurement of net deferred tax liability from new tax Act		$ 500,400
Foreign transition tax liability		0
Income tax benefit normally reported as a component of AOCI due to new tax act		$ 300