Income Taxes (Components Of Domestic And Foreign Deferred Tax Assets And Liabilities) (Details) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Income Tax Disclosure [Abstract]
Unpaid losses and loss adjustment expenses	$ 163,522	$ 164,497
Unearned premiums recognized for income tax purposes	102,020	85,952
Life and annuity benefits	84,890	78,370
Lease liabilities	55,362	0
Tax credit carryforwards	47,233	39,877
Net operating loss carryforwards	39,429	46,662
Accrued incentive compensation	35,132	30,308
Other differences between financial reporting and tax bases	52,604	39,763
Total gross deferred tax assets	580,192	485,429
Less valuation allowance	(45,544)	(36,286)
Total gross deferred tax assets, net of allowance	534,648	449,143
Investments	996,543	590,250
Goodwill and other intangible assets	134,573	124,953
Deferred policy acquisition costs	113,243	89,716
Right-of-use lease assets	49,583	0
Other differences between financial reporting and tax bases	101,426	90,269
Total gross deferred tax liabilities	1,395,368	895,188
Net deferred tax liability	$ 860,720	$ 446,045