Condensed Consolidated Statements of Stockholders' Equity (USD $) In Thousands, except Share data	Total stockholders equity	Common Stock [Member]	Additional Paid-in Capital [Member]	Total Accumulated Other Comprehensive (Loss) Earnings [Member]	Foreign Currency Translation Adjustments [Member]	Unrealized Derivative Gains (Losses) [Member]	Minimum Retirement Benefit Liability Adjustments [Member]	Deferred Compensation in Equity [Member]	Retained Earnings [Member]	Treasury Stock at Cost [Member]	Treasury Stock Held for Deferred Compensaton [Member]	Total
Balances at Sep. 30, 2011	$ 919,097	$ 106	$ 81,453	$ 3,626	$ 22,103	$ (484)	$ (17,993)	$ 4,581	$ 949,573	$ (115,661)	$ (4,581)
Balance, Treasury Stock, shares at Sep. 30, 2011										(4,070,000)
Balance, Common Stock, shares at Sep. 30, 2011		72,960,000
Balance, Treasury stock held for deferred compensation, Shares at Sep. 30, 2011											(315,000)
Net earnings	28,416								28,416			28,416
Cash dividends paid	(4,823)								(4,823)
Purchases of treasury stock	(4,663)									(4,663)
Purchases of treasury stock, shares										(122,000)
Sales of treasury stock	2,166		(683)							2,849
Sales of treasury stock, shares										186,000
Tax benefit attributable to exercise of stock options	1,691		1,691
Stock-based compensation	3,647		3,647
Purchases of stock by deferred compensation plan	46		28					72		18	(72)
Purchases of stock by deferred compensation plan, shares										1,000	(1,000)
Distribution of stock from deferred compensation plan								(11)			11
Distribution of stock from deferred compensation plan, shares											2,000
Foreign currency translation adjustments	(8,381)			(8,381)	(8,381)
Reclassification of unrecognized derivative losses to earnings	45			45		45						45
Minimum retirement benefits liability adjustments	31			31			31
Taxes on changes in accumulated other comprehensive earnings	928			928	945	(17)
Balances at Dec. 31, 2011	938,200	106	86,136	(3,751)	14,667	(456)	(17,962)	4,642	973,166	(117,457)	(4,642)
Balance, Treasury Stock, shares at Dec. 31, 2011										(4,005,000)
Balance, Common Stock, shares at Dec. 31, 2011		72,960,000
Balance, Treasury stock held for deferred compensation, Shares at Dec. 31, 2011											(314,000)
Balances at Sep. 30, 2012	1,008,115	106	97,826	(11,723)	17,447	(376)	(28,794)	4,344	1,069,811	(147,905)	(4,344)	1,008,115
Balance, Treasury Stock, shares at Sep. 30, 2012										(4,536,000)		(4,536,000)
Balance, Common Stock, shares at Sep. 30, 2012		72,960,000										72,960,000
Balance, Preferred Stock, shares at Sep. 30, 2012												0
Balance, Treasury stock held for deferred compensation, Shares at Sep. 30, 2012											(276,000)	(276,000)
Net earnings	27,368								27,368			27,368
Cash dividends paid	(5,474)								(5,474)
Purchases of treasury stock	(3,978)									(3,978)
Purchases of treasury stock, shares										(109,000)
Sales of treasury stock	2,727		(4,509)							7,236
Sales of treasury stock, shares										252,000
Tax benefit attributable to exercise of stock options	2,088		2,088
Stock-based compensation	3,438		3,438
Purchases of stock by deferred compensation plan	20		8					43		12	(43)
Purchases of stock by deferred compensation plan, shares										1,000	(1,000)
Distribution of stock from deferred compensation plan								(1)			1
Foreign currency translation adjustments	4,451			4,451	4,451
Reclassification of unrecognized derivative losses to earnings	43			43		43						43
Minimum retirement benefits liability adjustments	237			237			237
Taxes on changes in accumulated other comprehensive earnings	595			595	612	(17)
Balances at Dec. 31, 2012	$ 1,039,630	$ 106	$ 98,851	$ (6,397)	$ 22,510	$ (350)	$ (28,557)	$ 4,386	$ 1,091,705	$ (144,635)	$ (4,386)	$ 1,039,630
Balance, Treasury Stock, shares at Dec. 31, 2012										(4,392,000)		(4,392,000)
Balance, Common Stock, shares at Dec. 31, 2012		72,960,000										72,960,000
Balance, Preferred Stock, shares at Dec. 31, 2012												0
Balance, Treasury stock held for deferred compensation, Shares at Dec. 31, 2012											(277,000)	(277,000)