Business Segment Information (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2011	Sep. 30, 2010	Sep. 30, 2011 Y D contract customer segment	Sep. 30, 2010
Operating results by business segment
Net revenue	$ 686,843	$ 750,319	$ 2,077,936	$ 2,220,030
Cost of care	(448,051)	(467,160)	(1,323,197)	(1,416,317)
Cost of goods sold	(57,636)	(55,071)	(167,559)	(166,138)
Direct service costs	(100,824)	(111,068)	(307,699)	(327,596)
Other operating expenses	(29,214)	(30,513)	(85,685)	(91,856)
Stock compensation expense	4,425	3,596	13,408	11,830
Segment profit (loss)	55,543	90,103	207,204	229,953
Number of customers subcontracted by Public Sector with Medicaid Administration			1
Commercial
Operating results by business segment
Net revenue	135,365	165,270	425,086	487,954
Cost of care	(81,503)	(84,485)	(235,938)	(265,740)
Direct service costs	(36,582)	(40,156)	(113,502)	(115,340)
Stock compensation expense	208	124	677	556
Segment profit (loss)	17,488	40,753	76,323	107,430
Public Sector
Operating results by business segment
Net revenue	362,104	364,102	1,074,904	1,081,581
Cost of care	(318,807)	(310,261)	(933,662)	(930,932)
Direct service costs	(16,741)	(17,554)	(50,203)	(50,559)
Stock compensation expense	218	181	654	554
Segment profit (loss)	26,774	36,468	91,693	100,644
Radiology Benefits Management
Operating results by business segment
Net revenue	78,659	116,379	258,479	331,099
Cost of care	(49,186)	(72,980)	(157,731)	(220,211)
Direct service costs	(14,717)	(17,366)	(47,280)	(47,605)
Stock compensation expense	355	362	1,238	1,123
Segment profit (loss)	15,111	26,395	54,706	64,406
Specialty Pharmaceutical Management
Operating results by business segment
Net revenue	73,792	68,609	213,388	204,740
Cost of goods sold	(57,636)	(55,071)	(167,559)	(166,138)
Direct service costs	(6,563)	(8,064)	(18,658)	(19,537)
Stock compensation expense	380	108	639	365
Segment profit (loss)	9,973	5,582	27,810	19,430
Medicaid Administration
Operating results by business segment
Net revenue	57,692	42,606	167,622	121,303
Cost of care	(19,324)	(6,081)	(57,409)	(6,081)
Direct service costs	(26,221)	(27,928)	(78,056)	(94,555)
Stock compensation expense	36	36	100	76
Segment profit (loss)	12,183	8,633	32,257	20,743
Corporate and Elimination
Operating results by business segment
Net revenue	(20,769)	(6,647)	(61,543)	(6,647)
Cost of care	20,769	6,647	(61,543)	6,647
Other operating expenses	(29,214)	(30,513)	(85,685)	(91,856)
Stock compensation expense	3,228	2,785	10,100	9,156
Segment profit (loss)	$ (25,986)	$ (27,728)	$ (75,585)	$ (82,700)