SEGMENT INFORMATION (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2013 Number_of_Segmnts	Mar. 31, 2012
Segment Reporting [Abstract]
Number of Reportable Segments	3
Operating revenues [Abstract]
Managed care premiums	$ 3,236,663	$ 3,386,268
Management services	283,572	305,699
Total operating revenues	3,520,235	3,691,967
Medical costs	2,686,651	2,808,348
Cost of sales	59,485	67,952
Gross margin	774,099	815,667
Selling, general and administrative	520,300	502,888
Depreciation and amortization	37,631	36,303
Operating earnings	216,168	276,476
Commercial Products [Member]
Operating revenues [Abstract]
Managed care premiums	1,322,718	1,481,275
Management services	108,084	113,777
Total operating revenues	1,430,802	1,595,052
Medical costs	1,021,785	1,177,985
Cost of sales	0	0
Gross margin	409,017	417,067
Government Programs [Member]
Operating revenues [Abstract]
Managed care premiums	1,928,726	1,915,795
Management services	0	0
Total operating revenues	1,928,726	1,915,795
Medical costs	1,679,647	1,641,165
Cost of sales	0	0
Gross margin	249,079	274,630
Workers' Compensation [Member]
Operating revenues [Abstract]
Managed care premiums	0	0
Management services	175,488	191,922
Total operating revenues	175,488	191,922
Medical costs	0	0
Cost of sales	59,485	67,952
Gross margin	116,003	123,970
Elimination [Member]
Operating revenues [Abstract]
Managed care premiums	(14,781)	(10,802)
Management services	0	0
Total operating revenues	(14,781)	(10,802)
Medical costs	(14,781)	(10,802)
Cost of sales	0	0
Gross margin	$ 0	$ 0