Consolidated Statements of Cash Flows - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Cash Flows from Operating Activities
Net Income	$ 135,536	$ 29,174	$ 32,461
Adjustments to Reconcile Net Income to Net Cash Provided by Operating Activities:
Depreciation and amortization	28,389	28,850	28,305
Non-cash operating lease cost	3,349	3,157	2,669
Stock-based compensation expense	11,212	9,299	7,161
Deferred income taxes	1,768	327	(1,830)
(Recovery of) provision for credit losses	(454)	231	186
Noncash loss on extinguishment of debt	0	0	180
Insurance recoveries related to loss on operating assets	0	8,546	0
Gain on sale-leaseback	(132,522)	0	0
Other	(505)	826	942
Changes in Assets and Liabilities:
Accounts receivable	(11,689)	8,877	2,380
Contract assets	(22,377)	(47,358)	(20,005)
Inventories	(17,129)	(20,183)	(8,491)
Production cost of contracts	(2,311)	(1,488)	(1,079)
Other assets	(4,902)	(212)	1,358
Accounts payable	2,793	(19,714)	11,620
Contract liabilities	13,813	13,747	(2,628)
Operating lease liabilities	(3,531)	(2,953)	(2,713)
Accrued and other liabilities	(2,005)	1,485	515
Net Cash (Used in) Provided by Operating Activities	(565)	12,611	51,031
Cash Flows from Investing Activities
Purchases of property and equipment	(16,863)	(12,510)	(18,290)
Proceeds from sale-leaseback	143,100	0	0
Proceeds from sale of assets	553	5	3
Insurance recoveries related to property and equipment	0	4,954	0
Life insurance proceeds	439	1,889	0
Payments for acquisition of Magnetic Seal LLC, net of cash acquired	(69,479)	0	0
Post closing cash received from the acquisition of Nobles Worldwide, Inc., net	0	190	0
Payments for acquisition of Nobles Worldwide, Inc., net of cash acquired	0	0	(76,647)
Net Cash Provided by (Used in) Investing Activities	57,750	(5,472)	(94,934)
Cash Flows from Financing Activities
Borrowings from senior secured revolving credit facility	96,000	65,900	298,400
Repayments of senior secured revolving credit facility	(121,000)	(40,900)	(298,400)
Borrowings from term loans	0	0	140,000
Repayments of term loans	(7,926)	(14,362)	(63,000)
Repayments of other debt	(362)	(288)	(169)
Debt issuance costs	0	0	(1,135)
Net cash paid upon issuance of common stock under stock plans	(4,047)	(607)	(2,472)
Net Cash (Used in) Provided by Financing Activities	(37,335)	9,743	73,224
Net Increase in Cash and Cash Equivalents	19,850	16,882	29,321
Cash and Cash Equivalents at Beginning of Year	56,466	39,584	10,263
Cash and Cash Equivalents at End of Year	$ 76,316	$ 56,466	$ 39,584