CONDENSED CONSOLIDATED STATEMENTS OF INCOME - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Revenues:
Net premiums	$ 2,763,786	$ 2,594,460	$ 5,501,599	$ 5,177,011
Investment income, net of related expenses	584,078	528,061	1,163,955	1,044,390
Investment related gains (losses), net:
Other-than-temporary impairments on fixed maturity securities	0	(3,350)	(9,453)	(3,350)
Other investment related gains (losses), net	12,472	(7,222)	29,713	(7,692)
Total investment related gains (losses), net	12,472	(10,572)	20,260	(11,042)
Other revenues	107,072	83,959	201,625	159,256
Total revenues	3,467,408	3,195,908	6,887,439	6,369,615
Benefits and Expenses:
Claims and other policy benefits	2,515,211	2,279,593	5,023,535	4,641,694
Interest credited	157,842	109,327	291,031	189,776
Policy acquisition costs and other insurance expenses	260,345	320,276	572,226	677,178
Other operating expenses	223,499	194,959	424,982	386,233
Interest expense	43,283	37,025	83,456	74,479
Collateral finance and securitization expense	7,151	7,440	15,568	15,042
Total benefits and expenses	3,207,331	2,948,620	6,410,798	5,984,402
Income before income taxes	260,077	247,288	476,641	385,213
Provision for income taxes	57,379	42,914	104,436	80,609
Net income	$ 202,698	$ 204,374	$ 372,205	$ 304,604
Earnings per share:
Basic earnings per share	$ 3.23	$ 3.19	$ 5.93	$ 4.74
Diluted earnings per share	$ 3.18	$ 3.13	$ 5.83	$ 4.65