Segment Information (Details 2)	3 Months Ended		6 Months Ended
	Jun. 30, 2011	Jun. 30, 2010	Jun. 30, 2011	Jun. 30, 2010
Well Point [Member]
Segment information percentage of revenue by top clients
Revenue percentage represented by largest clients	29.90%	28.60%	29.60%	28.40%
DoD [Member]
Segment information percentage of revenue by top clients
Revenue percentage represented by largest clients	21.70%	19.10%	21.70%	18.90%
Other [Member]
Segment information percentage of revenue by top clients
Revenue percentage represented by largest clients	6.30%	6.40%	6.20%	6.20%
Five Top Clients [Member]
Segment information percentage of revenue by top clients
Revenue percentage represented by largest clients	57.90%	54.10%	57.50%	53.50%