Business Segment Information (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2011	Jun. 30, 2010	Jun. 30, 2011	Jun. 30, 2010
Operating results by business segment
Net revenue	$ 698,338	$ 741,658	$ 1,391,093	$ 1,469,711
Cost of care	(441,446)	(472,478)	(875,146)	(949,157)
Cost of goods sold	(53,404)	(54,771)	(109,923)	(111,067)
Direct service costs	(103,388)	(108,536)	(206,875)	(216,528)
Other operating expenses	(28,391)	(31,081)	(56,471)	(61,343)
Stock compensation expense	4,205	3,706	8,983	8,234
Segment profit (loss)	75,914	78,498	151,661	139,850
Number of customers subcontracted by Public Sector with Medicaid Administration			1
Commercial
Operating results by business segment
Net revenue	139,686	160,982	289,721	322,684
Cost of care	(79,122)	(90,583)	(154,435)	(181,255)
Direct service costs	(39,112)	(37,716)	(76,920)	(75,184)
Stock compensation expense	218	194	469	432
Segment profit (loss)	21,670	32,877	58,835	66,677
Public Sector
Operating results by business segment
Net revenue	362,284	368,011	712,800	717,479
Cost of care	(309,934)	(311,609)	(614,855)	(620,671)
Direct service costs	(16,486)	(15,458)	(33,462)	(33,005)
Stock compensation expense	214	172	436	373
Segment profit (loss)	36,078	41,116	64,919	64,176
Radiology Benefits Management
Operating results by business segment
Net revenue	90,608	105,263	179,820	214,720
Cost of care	(53,828)	(70,286)	(108,545)	(147,231)
Direct service costs	(15,858)	(15,401)	(32,563)	(30,239)
Stock compensation expense	401	368	883	761
Segment profit (loss)	21,323	19,944	39,595	38,011
Specialty Pharmaceutical Management
Operating results by business segment
Net revenue	69,366	67,993	139,596	136,131
Cost of goods sold	(53,404)	(54,771)	(109,923)	(111,067)
Direct service costs	(6,083)	(5,922)	(12,095)	(11,473)
Stock compensation expense	133	114	259	257
Segment profit (loss)	10,012	7,414	17,837	13,848
Medicaid Administration
Operating results by business segment
Net revenue	56,637	39,409	109,930	78,697
Cost of care	(18,805)		(38,085)
Direct service costs	(25,849)	(34,039)	(51,835)	(66,627)
Stock compensation expense	41	22	64	40
Segment profit (loss)	12,024	5,392	20,074	12,110
Corporate and Elimination
Operating results by business segment
Net revenue	(20,243)		(40,774)
Cost of care	20,243		40,774
Other operating expenses	(28,391)	(31,081)	(56,471)	(61,343)
Stock compensation expense	3,198	2,836	6,872	6,371
Segment profit (loss)	$ (25,193)	$ (28,245)	$ (49,599)	$ (54,972)