Income Taxes (Components Of Domestic And Foreign Deferred Tax Assets And Liabilities) (Details) - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014
Income Tax Disclosure [Abstract]
Unpaid losses and loss adjustment expenses	$ 212,012	$ 239,588
Life and annuity benefits	156,950	143,102
Unearned premiums recognized for income tax purposes	102,076	108,960
Investments, including other-than-temporary impairments	65,641	28,106
Accrued incentive compensation	53,586	37,329
Stock-based compensation	21,948	31,314
Net operating loss carryforwards	18,771	36,359
Tax credit carryforwards	18,158	32,525
Other differences between financial reporting and tax bases	40,497	64,235
Total gross deferred tax assets	689,639	721,518
Less valuation allowance	(5,131)	(4,801)
Total gross deferred tax assets, net of allowance	684,508	716,717
Net unrealized gains on investments	626,776	759,212
Amortization of goodwill and other intangible assets	107,271	106,927
Deferred policy acquisition costs	88,036	101,766
Other differences between financial reporting and tax bases	38,613	59,359
Total gross deferred tax liabilities	860,696	1,027,264
Net deferred tax liability	$ 176,188	$ 310,547