Concentration of Customers and Suppliers (Details)	Dec. 31, 2012
Total revenues | Customer concentration | CVS
Concentration of Customers
Concentration risk percentage	50.00%
Total revenues | Customer concentration | Walgreens
Concentration of Customers
Concentration risk percentage	39.00%
Total revenues | Customer concentration | Express Scripts, Inc.
Concentration of Customers
Concentration risk percentage	10.00%
Gross accounts receivable | Credit concentration | CVS
Concentration of Customers
Concentration risk percentage	51.00%
Gross accounts receivable | Credit concentration | Walgreens
Concentration of Customers
Concentration risk percentage	44.00%
Gross accounts receivable | Credit concentration | Express Scripts, Inc.
Concentration of Customers
Concentration risk percentage	1.00%