CONSOLIDATED STATEMENTS OF SHAREHOLDERS' EQUITY - USD ($) shares in Thousands, $ in Thousands	Total	Common Stock [Member]	Additional Paid-in Capital [Member]	Retained Earnings [Member]	Accumulated Other Comprehensive Income (Loss) [Member]	Treasury Stock [Member]
Balance at Sep. 30, 2014	$ 580,171	$ 302	$ 285,305	$ 399,451	$ (19,186)	$ (85,701)
Balance (in Shares) at Sep. 30, 2014		30,248
Comprehensive income (loss):
Net earnings	42,512	$ 0	0	42,512	0	0
Translation adjustments, net of tax	(6,297)	0	0	0	(6,297)	0
Net unrecognized actuarial gain/loss, net of tax	(6,961)	0	0	0	(6,961)	0
Forward exchange contracts, net of tax	(94)	0	0	0	(94)	0
Cash dividends declared	(8,331)	0	0	(8,331)	0	0
Stock options and stock compensation plans, net of tax	1,430	$ 2	1,180	0	0	248
Stock options and stock compensation plans, net of tax (in Shares)		111
Purchases into treasury	(18,248)	$ 0	0	0	0	(18,248)
Ending Balance at Sep. 30, 2015	584,182	$ 304	286,485	433,632	(32,538)	(103,701)
Ending Balance (in Shares) at Sep. 30, 2015		30,359
Comprehensive income (loss):
Net earnings	45,882	$ 0	0	45,882	0	0
Translation adjustments, net of tax	(1,462)	0	0	0	(1,462)	0
Net unrecognized actuarial gain/loss, net of tax	(5,250)	0	0	0	(5,250)	0
Forward exchange contracts, net of tax	(33)	0	0	0	(33)	0
Cash dividends declared	(8,242)	0	0	(8,242)	0	0
Stock options and stock compensation plans, net of tax	4,335	$ 0	4,103	0	0	232
Stock options and stock compensation plans, net of tax (in Shares)		5
Purchases into treasury	(4,303)	$ 0	0	0	0	(4,303)
Ending Balance at Sep. 30, 2016	615,109	$ 304	290,588	471,272	(39,283)	(107,772)
Ending Balance (in Shares) at Sep. 30, 2016		30,364
Comprehensive income (loss):
Net earnings	53,703	$ 0	0	53,703	0	0
Translation adjustments, net of tax	6,383	0	0	0	6,383	0
Net unrecognized actuarial gain/loss, net of tax	5,573	0	0	0	5,573	0
Forward exchange contracts, net of tax	19	0	0	0	19	0
Cash dividends declared	(8,257)	0	0	(8,257)	0	0
Stock options and stock compensation plans, net of tax	(612)	$ 1	(803)	0	0	190
Stock options and stock compensation plans, net of tax (in Shares)		105
Ending Balance at Sep. 30, 2017	$ 671,918	$ 305	$ 289,785	$ 516,718	$ (27,308)	$ (107,582)
Ending Balance (in Shares) at Sep. 30, 2017		30,469