Income Taxes (Reconciliation Actual Income Taxes to Expected Federal Corporate Taxes) (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2015	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2015
Income Tax Disclosure [Abstract]
Expected U.S. federal corporate income tax rate, percent									34.00%
Tax expense (benefit) at the U.S. rate (34%)									$ 3,340	$ (1,890)	$ (1,630)
Effect of permanent book-tax differences									340	1,120	(1,570)
State tax provision									100	110	(40)
Valuation allowance for net deferred tax assets									(1,610)	2,690	2,490
Uncertain tax items									350	350	330
Foreign tax rate differential									(776)	1,050	1,890
Other items									0	(330)	440
Total provision	$ 474	$ 986	$ 194	$ 90	$ 1,060	$ 70	$ 1,670	$ 300	$ 1,744	$ 3,100	$ 1,910