Condensed Consolidated Statements Of Income (USD $) In Thousands, except Per Share data	3 Months Ended		9 Months Ended
	Sep. 30, 2011	Sep. 30, 2010	Sep. 30, 2011	Sep. 30, 2010
Revenues:
Premiums	$ 8,852,536	$ 8,134,645	$ 26,468,203	$ 24,673,259
Services	356,212	128,917	1,034,663	394,639
Investment income	91,895	87,250	272,626	252,495
Total revenues	9,300,643	8,350,812	27,775,492	25,320,393
Operating expenses:
Benefits	7,146,530	6,641,264	21,761,052	20,327,742
Operating costs	1,361,657	1,002,398	3,809,905	3,156,945
Depreciation and amortization	66,671	58,717	200,561	181,957
Total operating expenses	8,574,858	7,702,379	25,771,518	23,666,644
Income from operations	725,785	648,433	2,003,974	1,653,749
Interest expense	27,065	26,143	81,956	78,679
Income before income taxes	698,720	622,290	1,922,018	1,575,070
Provision for income taxes	253,960	229,069	701,795	583,005
Net income	$ 444,760	$ 393,221	$ 1,220,223	$ 992,065
Basic earnings per common share	$ 2.71	$ 2.35	$ 7.34	$ 5.90
Diluted earnings per common share	$ 2.67	$ 2.32	$ 7.24	$ 5.84
Dividends declared per common share	$ 0.25	$ 0.00	$ 0.50	$ 0.00