Reinsurance (Effect Of Reinsurance On Premiums Earned And Benefits Incurred) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Reinsurance [Line Items]
Direct earned premiums	$ 11,600,724	$ 11,250,949	$ 9,848,656
Premiums assumed	525,988	487,656	315,097
Premiums ceded	(3,775,715)	(3,106,463)	(2,403,957)
Net earned premiums	8,350,997	8,632,142	7,759,796
Direct policyholder benefits	6,962,357	6,947,121	4,639,958
Policyholder benefits assumed	310,873	330,276	234,290
Policyholder benefits ceded	(2,530,695)	(2,872,064)	(1,198,716)
Net policyholder benefits	4,742,535	4,405,333	3,675,532
Long Duration
Reinsurance [Line Items]
Direct earned premiums	509,080	510,822	555,368
Premiums assumed	8,410	8,762	10,117
Premiums ceded	(288,975)	(276,525)	(304,064)
Net earned premiums	228,515	243,059	261,421
Direct policyholder benefits	937,962	1,702,475	933,110
Policyholder benefits assumed	19,948	23,911	22,844
Policyholder benefits ceded	(647,873)	(1,373,953)	(590,281)
Net policyholder benefits	310,037	352,433	365,673
Short Duration
Reinsurance [Line Items]
Direct earned premiums	11,091,644	10,740,127	9,293,288
Premiums assumed	517,578	478,894	304,980
Premiums ceded	(3,486,740)	(2,829,938)	(2,099,893)
Net earned premiums	8,122,482	8,389,083	7,498,375
Direct policyholder benefits	6,024,395	5,244,646	3,706,848
Policyholder benefits assumed	290,925	306,365	211,446
Policyholder benefits ceded	(1,882,822)	(1,498,111)	(608,435)
Net policyholder benefits	$ 4,432,498	$ 4,052,900	$ 3,309,859