Segment Information (U.S. Government Related Sales by Segment) (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended								12 Months Ended
	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2012	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2012
Net sales	$ 565,447	$ 524,284	$ 482,467	$ 429,042	$ 558,365	$ 483,759	$ 485,513	$ 408,339	$ 2,001,240	$ 1,935,976	$ 1,865,627
Aerospace [Member]
Net sales	318,209	274,923	261,021	229,872	307,377	272,218	270,493	211,389	1,084,025	1,061,477	896,083
Energy [Member]
Net sales	247,238	249,361	221,446	199,170	250,988	211,541	215,020	196,950	917,215	874,499	969,544
Total of Reporting Segments [Member]
Net sales	565,447	524,284	482,467	429,042	558,365	483,759	485,513	408,339
U.S. Government Related [Member]
Net sales									339,893	405,362	343,843
U.S. Government Related [Member] | Aerospace [Member]
Net sales									331,788	393,607	332,711
U.S. Government Related [Member] | Energy [Member]
Net sales									8,105	11,755	11,132
Indirect Sales to U.S. Government [Member]
Net sales									260,394	297,303	261,864
Indirect Sales to U.S. Government [Member] | Aerospace [Member]
Net sales									254,806	289,197	254,636
Indirect Sales to U.S. Government [Member] | Energy [Member]
Net sales									5,588	8,106	7,228
Direct Sales to U.S. Government [Member]
Net sales									79,499	108,059	81,979
Direct Sales to U.S. Government [Member] | Aerospace [Member]
Net sales									76,982	104,410	78,075
Direct Sales to U.S. Government [Member] | Energy [Member]
Net sales									$ 2,517	$ 3,649	$ 3,904
Sales [Member] | U.S. Government Related [Member]
Percentage of total attributable to major customer									17.00%	21.00%	18.00%
Sales [Member] | Indirect Sales to U.S. Government [Member]
Percentage of total attributable to major customer									13.00%	15.00%	14.00%
Sales [Member] | Direct Sales to U.S. Government [Member]
Percentage of total attributable to major customer									4.00%	6.00%	4.00%
Sales [Member] | General Electric [Member]
Percentage of total attributable to major customer									15.00%	15.00%	14.00%
Trade Accounts Receivable [Member] | U.S. Government Related [Member]
Percentage of total attributable to major customer									2.00%	4.00%
Trade Accounts Receivable [Member] | General Electric [Member]
Percentage of total attributable to major customer									12.00%	11.00%