Income Taxes (Components Of Provision For Income Taxes) (Details) - USD ($) $ in Thousands	12 Months Ended
Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Income Tax Expense (Benefit), Continuing Operations [Abstract]
Federal, Current (expense) benefit	$ (16,870)	$ (34,842)	$ (13,601)
State, Current (expense) benefit	(294)	(240)	(156)
Foreign, including foreign withholding tax, Current (expense) benefit	(15,539)	(19,268)	(17,241)
Current (expense) benefit	32,703	54,350	30,998
Federal, Deferred (expense) benefit	(90,113)	(64,301)	(65,168)
State, Deferred (expense) benefit	(19,654)	(21,492)	(15,767)
Foreign, Deferred (expense) benefit	706	(385)	(481)
Deferred (expense) benefit	109,061	86,178	81,416
Income tax (expense) benefit	$ 141,764	$ 140,528	$ 112,414

Amount of current federal tax expense (benefit) pertaining to income (loss) from continuing operations.

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