Summary Of Major Accounting Policies Summary Of Major Accounting Policies - Revenue Recognition (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016	Jan. 01, 2018
Accounting Policies [Abstract]
Accounts receivable, billed		$ 476,903		$ 312,940
Effect of change, accounts receivable				(163,963)
Revenues	$ 1,909,482	1,921,507	$ 2,271,603
Cost of Goods and Services Sold	1,780,256	1,726,897	1,992,376
Income Tax Expense (Benefit)	26,494	(184,242)	18,760
Net Income (Loss), Including Portion Attributable to Noncontrolling Interest	(212,327)	166,398	$ 24,586
Unbilled Receivables, Current		0
Contract assets, current	256,201			171,956
Effect of change, contract assets				171,956
Accounts Receivable, Gross, Current	625,086	476,903		484,896
Effect of change, total accounts receivable				7,993
Inventory, Net	194,507	215,282
Effect of change, inventory				(34,187)
Accrued Liabilities, Current	392,105	350,258		324,803
Effect of change, total accrued liabilities				(25,455)
Effect of change, accrued liabilities				(63,045)
Accrued liabilities, (excl deferred revenue) adjusted				287,213
Deferred Revenue				37,590
Effect of change, deferred revenue				37,590
Liabilities, Other than Long-term Debt, Noncurrent	128,379
Effect of change, other long -term liabilities				(202)
Retained Earnings (Accumulated Deficit)	$ 2,204,548	$ 2,417,412		2,416,875
Effect of change, retained earnings				$ (537)