Information on Business Segments (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended	12 Months Ended
	Mar. 31, 2013 Segment	Dec. 31, 2014 Segment	Dec. 31, 2013	Dec. 31, 2012
Segment Reporting Information [Line Items]
Number of reportable segments	2	2
Revenues		$ 1,262,006	$ 1,091,566	$ 928,780
Operating profit		179,974	123,201	107,131
Assets		2,073,885	2,123,673	1,868,596
Depreciation and amortization		81,395	65,052	57,360
Capital expenditures		57,365	57,304	37,787
Interest expense		11,392	13,090	12,238
Other expense (income), net		2,082	2,537	2,631
Income from continuing operations before income taxes		166,500	107,574	92,262
General Electric [Member]
Segment Reporting Information [Line Items]
Revenue by major customer		19.00%	21.00%	23.00%
Aerospace [Member]
Segment Reporting Information [Line Items]
Revenues		440,000	404,000	390,500
Operating profit		71,600	51,300	57,900
Assets		655,000	567,100	533,500
Depreciation and amortization		24,900	23,200	21,200
Capital expenditures		20,900	23,800	8,600
Industrial [Member]
Segment Reporting Information [Line Items]
Revenues		822,100	687,600	538,300
Operating profit		108,400	71,900	49,300
Assets		1,282,000	1,410,400	907,100
Depreciation and amortization		54,700	38,400	24,400
Capital expenditures		36,100	31,300	24,300
Other [Member]
Segment Reporting Information [Line Items]
Revenues		0	0	0
Operating profit		0	0	0
Assets		136,900	146,200	428,000
Depreciation and amortization		1,800	3,500	11,800
Capital expenditures		$ 400	$ 2,200	$ 4,900