CONDENSED CONSOLIDATED STATEMENTS OF INCOME - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Revenues:
Net premiums	$ 2,489,797	$ 2,251,758	$ 7,335,944	$ 6,755,708
Investment income, net of related expenses	556,918	489,727	1,589,820	1,414,659
Investment related gains (losses), net:
Other-than-temporary impairments on fixed maturity securities	(390)	0	(20,980)	(34,663)
Other investment related gains (losses), net	23,043	86,624	160,451	118,665
Total investment related gains (losses), net	22,653	86,624	139,471	84,002
Other revenues	75,942	72,468	218,091	197,844
Total revenues	3,145,310	2,900,577	9,283,326	8,452,213
Benefits and Expenses:
Claims and other policy benefits	2,100,680	1,993,064	6,371,188	5,877,330
Interest credited	126,099	116,848	349,068	300,602
Policy acquisition costs and other insurance expenses	365,424	300,962	1,064,645	940,406
Other operating expenses	168,417	152,556	481,279	469,875
Interest expense	36,836	43,063	108,590	96,201
Collateral finance and securitization expense	7,692	6,484	21,235	19,396
Total benefits and expenses	2,805,148	2,612,977	8,396,005	7,703,810
Income before income taxes	340,162	287,600	887,321	748,403
Provision for income taxes	112,571	88,881	282,028	237,109
Net income	$ 227,591	$ 198,719	$ 605,293	$ 511,294
Earnings per share:
Basic earnings per share	$ 3.53	$ 3.10	$ 9.39	$ 7.95
Diluted earnings per share	3.47	3.07	9.23	7.87
Dividends declared per share	$ 0.50	$ 0.41	$ 1.32	$ 1.15