Summary Of Significant Accounting Policies (Condensed Consolidated Cash Flow) (Details) - USD ($) $ in Thousands	3 Months Ended												12 Months Ended
	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Cash flows from operating activities:
Net income (loss)	$ 27,716	$ 7,799	$ 10,943	$ (23,641)	$ (76,361)	$ 17,831	$ 18,074	$ 8,555	$ 19,327	$ 22,544	$ 12,688	$ 9,374	$ 22,817	$ (31,901)	$ 63,933
Adjustments to reconcile net income (loss) to net cash provided by operating activities:
Depreciation													38,439	36,668	41,398
Amortization													13,400	12,004	13,741
Provision for doubtful accounts													1,712	1,697	0
Deferred income taxes													7,628	7,422	8,390
Gain on the sale of property, plant and equipment													(262)	(202)	(224)
Asset impairments													96	42	142
Stock-based compensation expense													10,089	7,815	5,322
Excess tax benefits from stock-based compensation													0	0	(663)
Changes in operating assets and liabilities:
Accounts receivable													(33,952)	4,657	37,573
Contract assets													6,414	9,710	(10,931)
Inventories													(43,264)	(24,570)	38,397
Prepaid expenses and other assets													10,238	(7,812)	2,207
Accounts payable													61,391	29,542	76,039
Accrued liabilities													5,778	13,519	(28)
Income taxes													(23,837)	87,251	(2,208)
Net cash provided by operations													76,687	145,842	273,088
Cash flows from investing activities:
Net cash used in investing activities													(68,849)	(56,121)	(21,245)
Cash flows from financing activities:
Net used in financing activities													(290,967)	(31,352)	(35,310)
Effect of exchange rate changes													(1,315)	2,744	(1,095)
Net increase in cash and cash equivalents													(284,444)	61,113	215,438
Cash and cash equivalents at beginning of year				$ 742,546				$ 681,433				$ 465,995	742,546	681,433	465,995
Cash and cash equivalents at end of period	$ 458,102				$ 742,546				$ 681,433				$ 458,102	742,546	681,433
Accounting Standards Update 2014-09 [Member] | As Previously Reported [Member] | Calculated Under Revenue Guidance In Effect Before Topic 606 [Member]
Cash flows from operating activities:
Net income (loss)														(31,965)	64,047
Adjustments to reconcile net income (loss) to net cash provided by operating activities:
Depreciation														36,668	41,398
Amortization														12,004	13,741
Provision for doubtful accounts														1,697
Deferred income taxes														9,262	7,055
Gain on the sale of property, plant and equipment														(202)	(224)
Asset impairments														42	142
Stock-based compensation expense														7,815	5,322
Excess tax benefits from stock-based compensation															663
Changes in operating assets and liabilities:
Accounts receivable														4,657	37,573
Contract assets														0	0
Inventories														(14,015)	27,749
Prepaid expenses and other assets														(10,434)	3,147
Accounts payable														29,542	76,039
Accrued liabilities														13,519	(28)
Income taxes														87,252	(2,210)
Net cash provided by operations														145,842	273,088
Cash flows from investing activities:
Net cash used in investing activities														(56,121)	(21,245)
Cash flows from financing activities:
Net used in financing activities														(31,352)	(35,310)
Effect of exchange rate changes														2,744	(1,095)
Net increase in cash and cash equivalents														61,113	215,438
Accounting Standards Update 2014-09 [Member] | Restatement Adjustment [Member] | Adjustments [Member]
Cash flows from operating activities:
Net income (loss)														64	(114)
Adjustments to reconcile net income (loss) to net cash provided by operating activities:
Depreciation														0	0
Amortization														0	0
Provision for doubtful accounts														0
Deferred income taxes														(1,840)	1,335
Gain on the sale of property, plant and equipment														0	0
Asset impairments														0	0
Stock-based compensation expense														0	0
Excess tax benefits from stock-based compensation															0
Changes in operating assets and liabilities:
Accounts receivable														0	0
Contract assets														9,710	(10,931)
Inventories														(10,555)	10,648
Prepaid expenses and other assets														2,622	(940)
Accounts payable														0	0
Accrued liabilities														0	0
Income taxes														(1)	2
Net cash provided by operations														0	0
Cash flows from investing activities:
Net cash used in investing activities														0	0
Cash flows from financing activities:
Net used in financing activities														0	0
Effect of exchange rate changes														0	0
Net increase in cash and cash equivalents														$ 0	$ 0