| Schedule of Segment Reporting Information, by Segment [Table Text Block] | The Company reports in two operating segments: PBM and HCIT. The Company evaluates segment performance based upon revenue and gross profit. Financial information by segment is presented below (in thousands): | | | | | | | | | | | | | | | | | | Three Months Ended
September 30, | | Nine Months Ended September 30, | | 2011 | | 2010 | | 2011 | | 2010 | PBM: | | | | | | | | Revenue | $ | 1,256,369 |
| | $ | 463,042 |
| | $ | 3,511,148 |
| | $ | 1,341,839 |
| Cost of revenue | 1,188,197 |
| | 423,773 |
| | 3,330,886 |
| | 1,225,620 |
| Gross profit | $ | 68,172 |
| | $ | 39,269 |
| | $ | 180,262 |
| | $ | 116,219 |
| Total assets at September 30 | $ | 690,445 |
| | $ | 491,117 |
| | | | | HCIT: | | | | | | | | Revenue | $ | 30,921 |
| | $ | 26,880 |
| | $ | 85,833 |
| | $ | 79,677 |
| Cost of revenue | 16,751 |
| | 13,285 |
| | 45,973 |
| | 39,064 |
| Gross profit | $ | 14,170 |
| | $ | 13,595 |
| | $ | 39,860 |
| | $ | 40,613 |
| Total assets at September 30 | $ | 306,653 |
| | $ | 263,443 |
| | | | | Consolidated: | | | | | | | | Revenue | $ | 1,287,290 |
| | $ | 489,922 |
| | $ | 3,596,981 |
| | $ | 1,421,516 |
| Cost of revenue | 1,204,948 |
| | 437,058 |
| | 3,376,859 |
| | 1,264,684 |
| Gross profit | $ | 82,342 |
| | $ | 52,864 |
| | $ | 220,122 |
| | $ | 156,832 |
| Total assets at September 30 | $ | 997,098 |
| | $ | 754,560 |
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