Other Comprehensive Income (Loss) (Schedule Of Tax Expense (Benefit) Of Other Comprehensive Income (Loss)) (Details) - USD ($) $ in Thousands		12 Months Ended
		Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Other Comprehensive Income (Loss), Tax [Abstract]
Net holding gains arising during the period	[1]	$ (68,056)	$ 372,469	$ 112,399
Change in unrealized other-than-temporary impairment losses on fixed maturities arising during the period	[1]	0	0	6
Reclassification adjustments for net losses included in net income	[1]	2,086	(10,072)	(12,462)
Change in net unrealized gains on investments	[1]	(65,970)	362,397	99,943
Change in foreign currency translation adjustments		1,523	28	1,037
Change in net actuarial pension loss		622	1,284	(4,192)
Total		$ (63,825)	$ 363,709	$ 96,788

[1] Effective January 1, 2018, the Company adopted ASU No. 2016-01 and equity securities are no longer classified as available-for-sale with unrealized gains and losses recognized in other comprehensive income, rather, changes in the fair value of equity securities are now recognized in net income. Prior periods have not been restated to conform to the current presentation. See note 1.