Reinsurance (Premiums And Losses Ceded By The Company To Affiliate) (Details) - USD ($) $ in Thousands		12 Months Ended
		Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Related Party Transaction [Line Items]
Ceded written premiums		$ 3,015,606	$ 2,902,348	$ 2,858,320
Assumed written premiums		3,364,524	3,484,414	3,786,260
Bermuda Re [Member]
Related Party Transaction [Line Items]
Ceded written premiums		2,324,314	2,283,815	2,273,222
Ceded earned premiums		2,353,801	2,316,096	2,208,084
Ceded losses and LAE	[1]	1,307,722	1,293,997	1,196,118
Everest International [Member]
Related Party Transaction [Line Items]
Ceded written premiums		98	395	286
Ceded earned premiums		110	522	563
Ceded losses and LAE		3,467	673	(2,356)
Everest Canada [Member]
Related Party Transaction [Line Items]
Assumed written premiums		53,653	39,819	37,436
Assumed earned premiums		49,156	35,988	25,925
Assumed losses and LAE		38,568	20,345	15,401
Lloyd's Syndicate [Member]
Related Party Transaction [Line Items]
Assumed written premiums		18,994
Assumed earned premiums		5,038
Assumed losses and LAE		4,938
Mt. Logan Re Segregated Accounts [Member]
Related Party Transaction [Line Items]
Ceded written premiums		160,091	209,162	122,203
Ceded earned premiums		155,010	201,416	122,979
Ceded losses and LAE		38,739	40,753	28,844
Assumed written premiums		14,563	15,421	13,889
Assumed earned premiums		14,563	15,421	13,889
Assumed losses and LAE

[1] Ceded losses and LAE include the Mt. McKinley loss portfolio transfer that constitutes losses ceded under retroactive reinsurance and therefore, in accordance with FASB guidance, amortization of deferred gain on retroactive reinsurance is reflected in other income on the consolidated statements of operations and comprehensive income (loss). Upon the sale of Mt. McKinley, the value of the remaining deferred gain on retroactive reinsurance was included in the calculation of the realized gain on sale of subsidiary.