Information on Business Segments (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2012 Segment	Jun. 30, 2011	Jun. 30, 2012	Jun. 30, 2011
Segment Reporting Information [Line Items]
Number of reportable segments	3
Net sales	$ 293,422	$ 297,837	$ 596,518	$ 587,427
Operating profit	34,126	33,774	67,139	64,490
Interest expense	2,435	2,350	4,803	6,005
Other expense (income), net	95	321	948	728
Income from continuing operations before income taxes	31,596	31,103	61,388	57,757
Aerospace [Member]
Segment Reporting Information [Line Items]
Net sales	93,770	94,729	191,020	185,289
Operating profit	14,706	14,794	28,924	28,477
Industrial [Member]
Segment Reporting Information [Line Items]
Net sales	110,244	114,004	225,592	225,434
Operating profit	11,217	10,977	21,321	21,935
Distribution [Member]
Segment Reporting Information [Line Items]
Net sales	91,855	91,731	185,280	181,643
Operating profit	8,203	8,003	16,894	14,078
Intersegment sales [Member]
Segment Reporting Information [Line Items]
Net sales	$ (2,447)	$ (2,627)	$ (5,374)	$ (4,939)