Segment and Geographic Information (Reconciliation of Income From Segments to Consolidation) (Details) $ in Thousands		12 Months Ended
		Dec. 31, 2017 USD ($) segment	Dec. 31, 2016 USD ($)	Dec. 31, 2015 USD ($)
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Number of operating segments | segment		2
Net sales	[1]	$ 1,805,909	$ 1,808,376	$ 1,775,125
Operating income		114,175	105,923	104,519
Net gain (loss) on sale of assets		256	(11)	328
Interest expense, net		20,581	15,747	13,144
Other (income) expense, net		(784)	472	3,386
Earnings before income taxes		94,378	89,704	87,989
Income tax expense		44,552	30,850	27,551
Net earnings		49,826	58,854	60,438
Segment Reconciliation [Abstract]
Total assets		1,455,452	1,426,286	1,439,611
Capital expenditures		27,631	29,777	29,932
Depreciation and amortization		42,471	43,393	36,181
U.S. Government contracts | Aerospace
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Net sales		248,600	244,400	211,400
Operating Segments | Distribution
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Net sales		1,080,965	1,106,322	1,177,539
Operating income		52,482	41,859	49,441
Segment Reconciliation [Abstract]
Total assets	[2]	537,911	540,900	558,630
Capital expenditures		9,621	9,016	10,685
Depreciation and amortization		15,083	16,107	16,368
Operating Segments | Aerospace
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Net sales	[3]	724,944	702,054	597,586
Operating income		119,889	115,005	110,328
Segment Reconciliation [Abstract]
Total assets	[2]	810,278	720,823	738,426
Capital expenditures		17,208	17,935	13,378
Depreciation and amortization		23,717	23,584	16,275
Segment Reconciling Items
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Net gain (loss) on sale of assets		256	(11)	328
Corporate, Non-Segment
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Corporate expense		(58,452)	(50,930)	(55,578)
Segment Reconciliation [Abstract]
Total assets	[2],[4]	107,263	164,563	142,555
Capital expenditures		802	2,826	5,869
Depreciation and amortization		$ 3,671	$ 3,702	$ 3,538

[1] Service revenue was not material for the years ended December 31, 2017, 2016 and 2015.

[2] Identifiable assets are year-end assets at their respective net carrying values segregated as to segment and corporate use.

[3] Net sales by the Aerospace segment under contracts with USG agencies (including sales to foreign governments through foreign military sales contracts with USG agencies) totaled $248.6 million, $244.4 million and $211.4 million in 2017, 2016 and 2015, respectively, and represent direct and indirect sales to the USG and related agencies.

[4] For the periods presented, the corporate identifiable assets are principally comprised of cash, short-term and long-term deferred income tax assets, cash surrender value of life insurance policies and fixed assets.