Summary Of Major Accounting Policies Summary of Major Accounting Policies - Revenue Recognition (Details) - USD ($) $ in Thousands	3 Months Ended			6 Months Ended
	Jun. 30, 2018	Mar. 31, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017	Jan. 01, 2018	Dec. 31, 2017
Accounting Policies [Abstract]
Interest Costs, Capitalized During Period	$ 1,831		$ 1,200	$ 3,409	$ 2,155
Accounts receivable, billed	335,858			335,858
Revenues	478,674	$ 416,413	515,036	895,087	961,212
Revenue, adjusted				884,358
effect of change, revenue				(10,729)
Cost of Goods and Services Sold	448,946		461,465	846,531	862,786
Cost of services and products, adjusted				845,767
Effect of change, cost of services and products				(764)
Income Tax Expense (Benefit)	3,294		1,252	9,182	169
Income taxes, adjusted				7,212
Effect of change, income taxes				(1,970)
Accounts Receivable, Net, Current	504,322			504,322			$ 476,903
Effect of change, total accounts receivable	(23,885)			(23,885)		$ 7,993
Effect of change, accounts receivable	0			0		(163,963)
Total accounts receivable, adjusted	480,437			480,437		484,896
Accounts receivable, adjusted	335,858			335,858		312,940
Inventory, Net	185,926			185,926			215,282
Inventory, adjusted	205,740			205,740		181,095
Accrued liabilities, excluding deferred revenue	306,089			306,089
Unbilled Receivables, Current	0			0		171,956	0
Contract assets, current, adjusted	0			0
Unbilled accounts receivable, current, adjusted	144,579			144,579
Contract assets, current	168,464			168,464
Effect of change, contract assets	(168,464)			(168,464)
Effect of change, unbilled accounts receivable	144,579			144,579
Inventory, Gross							215,282
Accrued Liabilities, Current	336,226			336,226			350,258
Accrued liabilities, (excl deferred revenue) adjusted	305,925			305,925		287,213
Total accrued liabilities, adjusted	341,378			341,378		324,803
Effect of change, accrued liabilities	(164)			(164)		(63,045)
Effect of change, total accrued liabilities	5,152			5,152		(25,455)
Deferred Revenue	30,137			30,137		37,590	0
Effect of change, deferred revenue	5,316			5,316
Deferred revenue without adoption of ASC 606	35,453			35,453
Effect of change, inventory	19,814			19,814		(34,187)
Other Liabilities, Noncurrent	122,610			122,610			131,323
Other long-term liabilities, adjusted	120,842			120,842		131,121
Effect of change, other long -term liabilities	(1,768)			(1,768)		(202)
Retained Earnings (Accumulated Deficit)	2,334,666			2,334,666		2,416,875	$ 2,417,412
Effect of change, retained earnings	(7,458)			(7,458)		$ (537)
Net Income (Loss), Including Portion Attributable to Noncontrolling Interest	(33,076)		$ 2,132	(82,209)	$ (5,402)
Effect of change, Net Income				(7,995)
Retained earnings, adjusted	$ 2,327,208			2,327,208
Net income, adjusted				$ (90,204)