Consolidated Statements of Cash Flows - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Statement of Cash Flows [Abstract]
Cash, Including Discontinued Operations		$ 27,711	$ 36,904
Net earnings	$ 209,829	54,169	49,826
Income (Loss) from Discontinued Operations, Net of Tax, Attributable to Parent	153,383	38,292	30,118
Cash flows from operating activities:
Net earnings	56,446	15,877	19,708
Adjustments to reconcile earnings from continuing operations, net of tax to net cash provided by operating activities:
Depreciation and amortization	25,854	27,875	27,388
Amortization of debt issuance costs	1,996	1,806	2,014
Accretion of convertible notes discount	2,760	2,596	3,410
Provision for doubtful accounts	788	767	746
Gain (Loss) on Disposition of Business, Non Cash	3,971	5,722	0
Net loss (gain) on sale of assets	237	(1,031)	(31)
Impairment of Intangible Assets, Finite-lived	0	10,039	0
Loss on debt extinguishment	0	0	137
Net loss (gain) on derivative instruments	302	829	(1,126)
Stock compensation expense	4,669	5,484	4,902
Noncash Consideration on Sale of Aircraft	(3,100)	0	0
Deferred income taxes	182	7,834	27,718
Changes in assets and liabilities, excluding effects of acquisitions/divestitures:
Accounts receivable	(8,173)	(6,020)	(69,431)
Increase (Decrease) in Contract with Customer, Asset	(21,994)	(24,294)	0
increase (Decrease) in Capitalized Contract Cost	4,506	(5,834)	0
Inventories	(25,129)	7,135	22,363
Income tax refunds receivable	(6,296)	1,136	3,180
Increase (Decrease) in Operating Right of Use Assets	3,390	0	0
Other assets	(6,108)	(2,944)	3,458
Accounts payable - trade	14,034	10,807	7,432
Increase (Decrease) in Contract with Customer, Liability	(26,638)	96,430	0
Advances on contracts	0	0	(4,829)
Increase (Decrease) in Operating Lease Liabilities	(3,423)	0	0
Other current liabilities	6,085	(374)	2,967
Income taxes payable	7,888	(2,393)	212
Pension liabilities	4,170	(38,179)	(11,318)
Other long-term liabilities	6,071	5,446	(628)
Net Cash Provided by (Used in) Operating Activities, Continuing Operations	42,488	118,714	38,272
Cash Provided by (Used in) Operating Activities, Discontinued Operations	(50,288)	43,654	41,613
Net cash provided by operating activities from continuing operations	(7,800)	162,368	79,885
Cash flows from investing activities:
Proceeds from sale of assets	196	2,138	191
Proceeds from Divestiture of Businesses	655,030	0	0
Expenditures for property, plant & equipment	(22,447)	(21,504)	(18,010)
Acquisition of businesses including earn out adjustments, net of cash acquired	0	0	(1,365)
Other, net	(4,463)	(3,172)	(3,656)
Net Cash Provided by (Used in) Investing Activities, Continuing Operations	628,316	(22,538)	(22,840)
Cash Provided by (Used in) Investing Activities, Discontinued Operations	(9,838)	(7,423)	(8,995)
Net cash provided by (used in) investing activities of continuing operations	618,478	(29,961)	(31,835)
Cash flows from financing activities:
Net repayments under revolving credit agreements	(38,500)	(98,087)	(75,988)
Debt repayment	(76,875)	(7,500)	(6,875)
Proceeds from issuance of 2024 convertible notes	0	0	200,000
Repayment of convertible notes	(500)	0	(175,151)
Purchase of capped call - 2024 convertible notes	0	0	(20,500)
Proceeds from bond hedge settlement - 2017 convertible notes	0	0	58,564
Net change in bank overdraft	886	(279)	(37)
Proceeds from exercise of employee stock awards	19,676	7,351	7,370
Purchase of treasury shares	(30,060)	(19,278)	(11,552)
Dividends paid	(22,343)	(22,349)	(21,462)
Debt and equity issuance costs	(3,584)	0	(7,473)
Other	(1,413)	(1,003)	(523)
Net Cash Provided by (Used in) Financing Activities, Continuing Operations	(152,713)	(141,145)	(53,627)
Cash Provided by (Used in) Financing Activities, Discontinued Operations	7,967	(217)	(1,109)
Net cash used in financing activities of continuing operations	(144,746)	(141,362)	(54,736)
Net increase (decrease) in cash and cash equivalents	465,932	(8,955)	(6,686)
Disposal Group, Including Discontinued Operation, Cash and Cash Equivalents	(21,834)	(1,816)	(1,667)
Effect of exchange rate changes on cash and cash equivalents	(269)	(238)	2,385
Cash and cash equivalents at beginning of period	25,895	35,237
Cash and cash equivalents at end of period	$ 471,540	$ 25,895	$ 35,237