Income Taxes (Tax Expense and Effective Tax Rate) (Details) - USD ($) $ in Thousands	3 Months Ended
	Dec. 31, 2016	Dec. 31, 2015
Income Taxes
Earnings before income taxes	$ 47,059	$ 27,956
Income tax expense	$ 511	$ 2,136
Effective tax rate	1.10%	7.60%