Segment Information (U.S. Government Related Sales by Segment) (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2013	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2013
Net sales	$ 562,625	$ 494,810	$ 493,222	$ 487,646	$ 565,447	$ 524,284	$ 482,467	$ 429,042	$ 2,038,303	$ 2,001,240	$ 1,935,976
Aerospace [Member]
Net sales	335,207	288,480	281,426	255,770	318,209	274,923	261,021	229,872	1,160,883	1,084,025	1,061,477
Energy [Member]
Net sales	$ 227,418	$ 206,330	$ 211,796	$ 231,876	$ 247,238	$ 249,361	$ 221,446	$ 199,170	877,420	917,215	874,499
Total of Reporting Segments [Member]
Net sales									2,038,303	2,001,240	1,935,976
U.S. Government Related [Member]
Net sales									$ 364,388	$ 339,893	$ 405,362
Percentage of total attributable to major customer									18.00%	17.00%	21.00%
U.S. Government Related [Member] | Aerospace [Member]
Net sales									$ 350,713	$ 331,788	$ 393,607
U.S. Government Related [Member] | Energy [Member]
Net sales									13,675	8,105	11,755
Indirect Sales to U.S. Government [Member]
Net sales									$ 267,230	$ 260,394	$ 297,303
Percentage of total attributable to major customer									13.00%	13.00%	15.00%
Indirect Sales to U.S. Government [Member] | Aerospace [Member]
Net sales									$ 258,391	$ 254,806	$ 289,197
Indirect Sales to U.S. Government [Member] | Energy [Member]
Net sales									8,839	5,588	8,106
Direct Sales to U.S. Government [Member]
Net sales									$ 97,158	$ 79,499	$ 108,059
Percentage of total attributable to major customer									5.00%	4.00%	6.00%
Direct Sales to U.S. Government [Member] | Aerospace [Member]
Net sales									$ 92,322	$ 76,982	$ 104,410
Direct Sales to U.S. Government [Member] | Energy [Member]
Net sales									$ 4,836	$ 2,517	$ 3,649
Sales [Member] | General Electric [Member]
Percentage of total attributable to major customer									18.00%	15.00%	15.00%
Trade Accounts Receivable [Member] | U.S. Government Related [Member]
Percentage of total attributable to major customer									3.00%	2.00%
Trade Accounts Receivable [Member] | General Electric [Member]
Percentage of total attributable to major customer									15.00%	12.00%