Consolidated Statements Of Cash Flows - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018
Cash flows from operating activities:
Net income (loss)	$ 23,220	$ (12,698)
Adjustments to reconcile net income (loss) to net cash provided by operating activities:
Depreciation	18,420	19,373
Amortization	5,705	5,710
Provision for doubtful accounts	(1,462)	0
Deferred income taxes	1,555	10,936
Asset impairments	834	96
Gain on the sale of property, plant and equipment	(25)	(116)
Stock-based compensation expense	5,720	5,405
Leases	574	0
Changes in operating assets and liabilities, net of effects from business acquisition:
Accounts receivable	106,749	(8,980)
Contract assets	(15,464)	(1,735)
Inventories	(6,327)	(52,063)
Prepaid expenses and other assets	1,559	1,966
Accounts payable	(49,428)	23,103
Accrued liabilities	(13,243)	(16,025)
Income taxes	(9,615)	8,846
Net cash provided by (used in) operations	68,772	(16,182)
Cash flows from investing activities:
Proceeds from sales of investments at par	50	522
Additions to property, plant and equipment	(14,163)	(36,708)
Proceeds from the sale of property, plant and equipment	28	137
Additions to purchased software	(1,332)	(1,655)
Business acquisitions, net of cash acquired	0	(2,731)
Other	(29)	(129)
Net cash used in investing activities	(15,446)	(40,564)
Cash flows from financing activities:
Proceeds from stock options exercised	693	3,377
Employee taxes paid for shares withheld	(1,242)	(771)
Dividends paid	(12,079)	(7,136)
Borrowings under credit agreement	0	50,000
Principal payments on long-term debt	(2,441)	(59,121)
Share repurchases	(100,039)	(65,868)
Equity forward contract related to accelerated share repurchase	0	(10,000)
Net cash used in financing activities	(115,108)	(89,519)
Effect of exchange rate changes	293	(642)
Net decrease in cash and cash equivalents	(61,489)	(146,907)
Cash and cash equivalents at beginning of year	458,102	742,546
Cash and cash equivalents at end of period	$ 396,613	$ 595,639