CONDENSED CONSOLIDATED STATEMENTS OF INCOME - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Revenues:
Net premiums	$ 2,251,758	$ 2,089,345	$ 6,755,708	$ 6,242,240
Investment income, net of related expenses	489,727	389,597	1,414,659	1,267,027
Investment related gains (losses), net:
Other-than-temporary impairments on fixed maturity securities	0	(23,111)	(34,663)	(29,775)
Other investment related gains (losses), net	86,624	(88,235)	118,665	(90,166)
Total investment related gains (losses), net	86,624	(111,346)	84,002	(119,941)
Other revenues	72,468	71,038	197,844	200,261
Total revenues	2,900,577	2,438,634	8,452,213	7,589,587
Benefits and Expenses:
Claims and other policy benefits	1,993,064	1,831,819	5,877,330	5,473,453
Interest credited	116,848	34,008	300,602	231,932
Policy acquisition costs and other insurance expenses	300,962	249,702	940,406	827,157
Other operating expenses	152,556	142,270	469,875	395,488
Interest expense	43,063	35,565	96,201	107,043
Collateral finance and securitization expense	6,484	5,133	19,396	16,462
Total benefits and expenses	2,612,977	2,298,497	7,703,810	7,051,535
Income before income taxes	287,600	140,137	748,403	538,052
Provision for income taxes	88,881	56,603	237,109	199,013
Net income	$ 198,719	$ 83,534	$ 511,294	$ 339,039
Earnings per share:
Basic earnings per share	$ 3.10	$ 1.26	$ 7.95	$ 5.07
Diluted earnings per share	3.07	1.25	7.87	5.01
Dividends declared per share	$ 0.41	$ 0.37	$ 1.15	$ 1.03