Accounting Changes (Details) - USD ($) $ in Thousands			12 Months Ended
		Jan. 01, 2018	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Accounts receivable, net		$ 284,209	$ 301,094	$ 313,451
Contract with Customer, Asset, Net, Current		82,699	108,861	0
Capitalized Contract Cost, Net, Current		3,022	5,993	0
Inventories		293,763	294,912	367,437
Income tax refunds receivable			1,752	2,889
Other current assets		27,221	32,782	27,188
Deferred Tax Assets, Net		31,773	24,437
Capitalized Contract Cost, Net, Noncurrent		7,852	10,666	0
Accounts payable – trade		128,659	158,627	127,591
Contract with Customer, Liability, Current		10,705	28,865	0
Advances on contracts		0	0	8,527
Other current liabilities		51,796	54,836	52,812
Customer Advances or Deposits, Noncurrent			0
Income taxes payable		3,042	139	1,517
Contract with Customer, Liability, Noncurrent		689	78,562	0
Retained earnings		578,293	610,103	587,877
Inventory Write-down		32,500
Revenues			1,875,425	1,805,909	$ 1,808,376
Cost of Goods and Services Sold			1,325,388	1,260,318	1,260,855
Gross Profit			550,037	545,591	547,521
Selling, general and administrative expenses			444,904	432,067	443,704
Impairment of Intangible Assets, Finite-lived			10,039	0	0
Restructuring costs (Note 3)			8,008	2,661	1,032
Gain (Loss) on Disposition of Business			5,722	0	0
Net (gain) loss on sale of assets			(1,700)	(256)	11
Operating income			83,064	111,119	102,774
Interest expense, net			20,097	20,581	15,747
Net Periodic Defined Benefits Expense (Reversal of Expense), Excluding Service Cost Component			(12,127)	(3,056)	(3,149)
Other (income) expense, net			(143)	(784)	472
Earnings before income taxes			75,237	94,378	89,704
Income tax expense			21,068	44,552	30,850
Net earnings			54,169	49,826	58,854
Previously Reported [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Cost of Goods and Services Sold				1,258,437	1,259,284
Gross Profit				547,472	549,092
Selling, general and administrative expenses				430,892	442,126
Operating income				114,175	105,923
Net Periodic Defined Benefits Expense (Reversal of Expense), Excluding Service Cost Component				0	0
Accounting Standards Update 2017-07 [Member] | Restatement Adjustment [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Cost of Goods and Services Sold				1,881	1,571
Gross Profit				(1,881)	(1,571)
Selling, general and administrative expenses				1,175	1,578
Operating income				(3,056)	(3,149)
Net Periodic Defined Benefits Expense (Reversal of Expense), Excluding Service Cost Component				(3,056)	(3,149)
Difference between Revenue Guidance in Effect before and after Topic 606 [Member] | Accounting Standards Update 2014-09 [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Accounts receivable, net		(29,242)	14,965
Contract with Customer, Asset, Net, Current		82,699	(108,861)
Capitalized Contract Cost, Net, Current		3,022	(5,993)
Inventories		(73,674)	105,266
Income tax refunds receivable			4,933
Other current assets		33	(208)
Deferred Tax Assets, Net		4,170	(4,315)
Capitalized Contract Cost, Net, Noncurrent		7,852	(10,666)
Accounts payable – trade		1,068	(935)
Contract with Customer, Liability, Current		10,705	(28,865)
Advances on contracts		(8,527)	27,149
Other current liabilities		(1,016)	1,913
Customer Advances or Deposits, Noncurrent			78,562
Income taxes payable		1,525
Contract with Customer, Liability, Noncurrent		689	(78,562)
Retained earnings		(9,584)	(4,141)
Inventory Write-down		32,500
Revenues		62,300	(64,257)
Cost of Goods and Services Sold			(45,530)
Gross Profit		20,200	(18,727)
Selling, general and administrative expenses			(2,281)
Impairment of Intangible Assets, Finite-lived			0
Restructuring costs (Note 3)			0
Gain (Loss) on Disposition of Business			539
Net (gain) loss on sale of assets			0
Operating income			(16,985)
Interest expense, net			0
Net Periodic Defined Benefits Expense (Reversal of Expense), Excluding Service Cost Component			0
Other (income) expense, net			0
Earnings before income taxes			(16,985)
Income tax expense			(3,261)
Net earnings			(13,724)
Difference between Revenue Guidance in Effect before and after Topic 606 [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Accounts receivable, net			316,059	313,451
Contract with Customer, Asset, Net, Current			0	0
Capitalized Contract Cost, Net, Current			0	0
Inventories			400,178	367,437
Income tax refunds receivable			6,685
Other current assets			32,574	27,188
Deferred Tax Assets, Net			20,122	27,603
Capitalized Contract Cost, Net, Noncurrent			0	0
Accounts payable – trade			157,692	127,591
Contract with Customer, Liability, Current			0	0
Advances on contracts			27,149	8,527
Other current liabilities			56,749	52,812
Customer Advances or Deposits, Noncurrent			78,562
Income taxes payable				1,517
Contract with Customer, Liability, Noncurrent			0	0
Retained earnings		$ (9,600)	605,962	587,877
Revenues			1,811,168
Cost of Goods and Services Sold			1,279,858
Gross Profit			531,310
Selling, general and administrative expenses			442,623
Impairment of Intangible Assets, Finite-lived			10,039
Restructuring costs (Note 3)			8,008
Gain (Loss) on Disposition of Business			6,261
Net (gain) loss on sale of assets			(1,700)
Operating income			66,079
Interest expense, net			20,097
Net Periodic Defined Benefits Expense (Reversal of Expense), Excluding Service Cost Component			(12,127)
Other (income) expense, net			(143)
Earnings before income taxes			58,252
Income tax expense			17,807
Net earnings			40,445
Distribution
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Revenues			1,139,431	1,080,965	1,106,322
Aerospace
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Revenues			735,994	724,944	702,054
Operating Segments [Member] | Distribution
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Revenues			1,139,431	1,080,965	1,106,322
Operating income			51,529	51,372	40,813
Operating Segments [Member] | Distribution | Previously Reported [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Operating income				52,482	41,859
Operating Segments [Member] | Distribution | Accounting Standards Update 2017-07 [Member] | Restatement Adjustment [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Operating income				(1,110)	(1,046)
Operating Segments [Member] | Aerospace
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Revenues	[1]		735,994	724,944	702,054
Operating income			$ 94,357	117,654	112,846
Operating Segments [Member] | Aerospace | Previously Reported [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Operating income				119,889	115,005
Operating Segments [Member] | Aerospace | Accounting Standards Update 2017-07 [Member] | Restatement Adjustment [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Operating income				(2,235)	(2,159)
Corporate, Non-Segment
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Operating income				(58,163)	(50,874)
Corporate, Non-Segment | Previously Reported [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Operating income				(58,452)	(50,930)
Corporate, Non-Segment | Accounting Standards Update 2017-07 [Member] | Restatement Adjustment [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Operating income				$ 289	$ 56

[1] 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 $281.3 million, $248.6 million and $244.4 million in 2018, 2017 and 2016, respectively, and represent direct and indirect sales to the USG and related agencies.