Segment Information (U.S. Government Related Sales by Segment) (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended								12 Months Ended
	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2012	Sep. 30, 2012	Jun. 30, 2012	Mar. 31, 2012	Dec. 31, 2011	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2011
Net sales	$ 558,365	$ 483,759	$ 485,513	$ 408,339	$ 528,697	$ 460,241	$ 468,793	$ 407,896	$ 1,935,976	$ 1,865,627	$ 1,711,702
Aerospace [Member]
Net sales	307,377	272,218	270,493	211,389	264,046	214,474	224,337	193,226	1,061,477	896,083	843,032
Energy [Member]
Net sales	250,988	211,541	215,020	196,950	264,651	245,767	244,456	214,670	874,499	969,544	868,670
Total of Reporting Segments [Member]
Net sales	558,365	483,759	485,513	408,339	528,697	460,241	468,793	407,896
U.S. Government Related [Member]
Net sales									405,362	343,843	330,556
U.S. Government Related [Member] | Aerospace [Member]
Net sales									393,607	332,711	319,578
U.S. Government Related [Member] | Energy [Member]
Net sales									11,755	11,132	10,978
Indirect Sales to U.S. Government [Member]
Net sales									297,303	261,864	259,992
Indirect Sales to U.S. Government [Member] | Aerospace [Member]
Net sales									289,197	254,636	252,462
Indirect Sales to U.S. Government [Member] | Energy [Member]
Net sales									8,106	7,228	7,530
Direct Sales to U.S. Government [Member]
Net sales									108,059	81,979	70,564
Direct Sales to U.S. Government [Member] | Aerospace [Member]
Net sales									104,410	78,075	67,116
Direct Sales to U.S. Government [Member] | Energy [Member]
Net sales									$ 3,649	$ 3,904	$ 3,448
Sales [Member] | U.S. Government Related [Member]
Percentage of total attributable to major customer									21.00%	18.00%	19.00%
Sales [Member] | Indirect Sales to U.S. Government [Member]
Percentage of total attributable to major customer									15.00%	14.00%	15.00%
Sales [Member] | Direct Sales to U.S. Government [Member]
Percentage of total attributable to major customer									6.00%	4.00%	4.00%
Sales [Member] | General Electric [Member]
Percentage of total attributable to major customer									15.00%	14.00%	14.00%
Trade Accounts Receivable [Member] | U.S. Government Related [Member]
Percentage of total attributable to major customer									4.00%	2.00%
Trade Accounts Receivable [Member] | General Electric [Member]
Percentage of total attributable to major customer									11.00%	10.00%