Condensed consolidating financial information (Details) (USD $) In Millions	Jun. 30, 2011	Dec. 31, 2010	Jun. 30, 2010	Dec. 31, 2009
Condensed Consolidating Balance Sheet
Cash and cash equivalents	$ 291.0	$ 523.7	$ 1,631.2	$ 1,070.4
Restricted cash and investments	15.9	16.3
Receivables, net	1,939.4	1,720.9
Other current assets	450.2	680.4
Total current assets	2,696.5	2,941.3
Property and equipment, net	369.8	372.7
Investments in subsidiaries	0	0
Intercompany	0	0
Goodwill	5,486.8	5,486.2
Other intangible assets, net	1,656.2	1,725.0
Other assets	28.6	32.6
Total assets	10,237.9	10,557.8
Claims and rebates payable	2,530.9	2,666.5
Accounts payable	745.6	656.7
Accrued expenses	487.2	593.9
Current maturities of long-term debt	999.8	0.1
Total current liabilities	4,763.5	3,917.2
Long-term debt	3,088.7	2,493.7
Intercompany	0	0
Other liabilities	557.7	540.3
Total stockholders' equity	1,828.0	3,606.6
Total liabilities and stockholders' equity	10,237.9	10,557.8
Express Scripts, Inc. [Member]
Condensed Consolidating Balance Sheet
Cash and cash equivalents	198.7	456.7	1,569.7	1,005.0
Restricted cash and investments	0	0
Receivables, net	1,322.3	1,175.6
Other current assets	24.6	249.0
Total current assets	1,545.6	1,881.3
Property and equipment, net	236.5	231.5
Investments in subsidiaries	6,558.0	6,382.2
Intercompany	0	0
Goodwill	2,921.4	2,921.4
Other intangible assets, net	1,376.5	1,426.2
Other assets	23.5	20.6
Total assets	12,661.5	12,863.2
Claims and rebates payable	2,530.5	2,664.9
Accounts payable	726.4	634.4
Accrued expenses	58.4	288.7
Current maturities of long-term debt	999.8	0
Total current liabilities	4,315.1	3,588.0
Long-term debt	3,088.7	2,493.7
Intercompany	3,368.2	3,094.8
Other liabilities	61.5	80.1
Total stockholders' equity	1,828.0	3,606.6
Total liabilities and stockholders' equity	12,661.5	12,863.2
Guarantors [Member]
Condensed Consolidating Balance Sheet
Cash and cash equivalents	3.2	9.0	8.5	10.0
Restricted cash and investments	11.2	11.7
Receivables, net	605.7	536.2
Other current assets	388.7	396.0
Total current assets	1,008.8	952.9
Property and equipment, net	118.0	127.2
Investments in subsidiaries	0	0
Intercompany	3,525.7	3,214.0
Goodwill	2,538.8	2,538.8
Other intangible assets, net	275.8	294.8
Other assets	4.2	10.1
Total assets	7,471.3	7,137.8
Claims and rebates payable	0.4	1.6
Accounts payable	16.4	17.7
Accrued expenses	416.2	294.5
Current maturities of long-term debt	0	0.1
Total current liabilities	433.0	313.9
Long-term debt	0	0
Intercompany	0	0
Other liabilities	493.9	455.5
Total stockholders' equity	6,544.4	6,368.4
Total liabilities and stockholders' equity	7,471.3	7,137.8
Non-Guarantors [Member]
Condensed Consolidating Balance Sheet
Cash and cash equivalents	89.1	58.0	53.0	55.4
Restricted cash and investments	4.7	4.6
Receivables, net	11.4	9.1
Other current assets	36.9	35.4
Total current assets	142.1	107.1
Property and equipment, net	15.3	14.0
Investments in subsidiaries	0	0
Intercompany	0	0
Goodwill	26.6	26.0
Other intangible assets, net	3.9	4.0
Other assets	0.9	1.9
Total assets	188.8	153.0
Claims and rebates payable	0	0
Accounts payable	2.8	4.6
Accrued expenses	12.6	10.7
Current maturities of long-term debt	0	0
Total current liabilities	15.4	15.3
Long-term debt	0	0
Intercompany	157.5	119.2
Other liabilities	2.3	4.7
Total stockholders' equity	13.6	13.8
Total liabilities and stockholders' equity	188.8	153.0
Eliminations [Member]
Condensed Consolidating Balance Sheet
Cash and cash equivalents	0	0
Restricted cash and investments	0	0
Receivables, net	0	0
Other current assets	0	0
Total current assets	0	0
Property and equipment, net	0	0
Investments in subsidiaries	(6,558.0)	(6,382.2)
Intercompany	(3,525.7)	(3,214.0)
Goodwill	0	0
Other intangible assets, net	0	0
Other assets	0	0
Total assets	(10,083.7)	(9,596.2)
Claims and rebates payable	0	0
Accounts payable	0	0
Accrued expenses	0	0
Current maturities of long-term debt	0	0
Total current liabilities	0	0
Long-term debt	0	0
Intercompany	(3,525.7)	(3,214.0)
Other liabilities	0	0
Total stockholders' equity	(6,558.0)	(6,382.2)
Total liabilities and stockholders' equity	$ (10,083.7)	$ (9,596.2)