Income Tax (Narrative) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Income Tax Disclosure [Abstract]
Deferred Tax Assets, Valuation Allowance	$ 133,354	$ 127,132
Tax Adjustments Settlements And Unusual Provisions	4,200
Deferred Tax Liability Not Recognized, Amount of Unrecognized Deferred Tax Liability	1,147,200	992,900
Proceeds from Income Tax Refunds	6,900	136,800	$ 9,300
Cash paid for income taxes	68,000	178,400	79,600
Operating Loss Carryforwards	1,353,600	1,771,000
Operating Loss Carryforwards With Expiration Dates	50,300
Income Tax Credits and Adjustments	100,900	77,500
Deferred Tax Assets Income Tax Credits And Adjustments Subject To Expiration	19,700
Unrecognized Tax Benefits	297,290	296,213	274,661	$ 279,801
Unrecognized Tax Benefits that Would Impact Effective Tax Rate	30,300
Unrecognized Tax Benefits, Interest on Income Taxes Expense	(8,400)	8,200	$ (36,600)
Income Tax Examination, Penalties Expense	300
Unrecognized Tax Benefits, Interest on Income Taxes Accrued	$ 20,400	$ 28,800