Condensed consolidating financial information (Details) (USD $) In Millions	Sep. 30, 2011	Dec. 31, 2010	Sep. 30, 2010	Dec. 31, 2009
Condensed Consolidating Balance Sheet
Cash and cash equivalents	$ 1,062.6	$ 523.7	$ 267.5	$ 1,070.4
Restricted cash and investments	19.9	16.3
Receivables, net	1,770.7	1,720.9
Other current assets	453.2	680.4
Total current assets	3,306.4	2,941.3
Property and equipment, net	388.8	372.7
Investments in subsidiaries	0	0
Intercompany	0	0
Goodwill	5,485.4	5,486.2
Other intangible assets, net	1,665.8	1,725.0
Other assets	25.3	32.6
Total assets	10,871.7	10,557.8
Claims and rebates payable	2,710.9	2,666.5
Accounts payable	744.3	656.7
Accrued expenses	688.6	593.9
Current maturities of long-term debt	999.9	0.1
Total current liabilities	5,143.7	3,917.2
Long-term debt	2,989.3	2,493.7
Intercompany	0	0
Other liabilities	574.0	540.3
Total stockholders' equity	2,164.7	3,606.6
Total liabilities and stockholders' equity	10,871.7	10,557.8
Express Scripts, Inc. [Member]
Condensed Consolidating Balance Sheet
Cash and cash equivalents	985.3	456.7	194.2	1,005.0
Restricted cash and investments	4.0	0
Receivables, net	1,178.0	1,175.6
Other current assets	39.4	249.0
Total current assets	2,206.7	1,881.3
Property and equipment, net	254.6	231.5
Investments in subsidiaries	6,678.3	6,382.2
Intercompany	0	0
Goodwill	2,921.4	2,921.4
Other intangible assets, net	1,395.9	1,426.2
Other assets	22.5	20.6
Total assets	13,479.4	12,863.2
Claims and rebates payable	2,710.5	2,664.9
Accounts payable	724.7	634.4
Accrued expenses	177.2	288.7
Current maturities of long-term debt	999.9	0
Total current liabilities	4,612.3	3,588.0
Long-term debt	2,989.3	2,493.7
Intercompany	3,656.4	3,094.8
Other liabilities	56.7	80.1
Total stockholders' equity	2,164.7	3,606.6
Total liabilities and stockholders' equity	13,479.4	12,863.2
Guarantors [Member]
Condensed Consolidating Balance Sheet
Cash and cash equivalents	5.5	9.0	8.1	10.0
Restricted cash and investments	11.3	11.7
Receivables, net	562.0	536.2
Other current assets	387.4	396.0
Total current assets	966.2	952.9
Property and equipment, net	119.0	127.2
Investments in subsidiaries	0	0
Intercompany	3,757.0	3,214.0
Goodwill	2,538.8	2,538.8
Other intangible assets, net	266.3	294.8
Other assets	0.4	10.1
Total assets	7,647.7	7,137.8
Claims and rebates payable	0.4	1.6
Accounts payable	4.1	17.7
Accrued expenses	478.4	294.5
Current maturities of long-term debt	0	0.1
Total current liabilities	482.9	313.9
Long-term debt	0	0
Intercompany	0	0
Other liabilities	515.3	455.5
Total stockholders' equity	6,649.5	6,368.4
Total liabilities and stockholders' equity	7,647.7	7,137.8
Non-Guarantors [Member]
Condensed Consolidating Balance Sheet
Cash and cash equivalents	71.8	58.0	65.2	55.4
Restricted cash and investments	4.6	4.6
Receivables, net	30.7	9.1
Other current assets	26.4	35.4
Total current assets	133.5	107.1
Property and equipment, net	15.2	14.0
Investments in subsidiaries	0	0
Intercompany	0	0
Goodwill	25.2	26.0
Other intangible assets, net	3.6	4.0
Other assets	2.4	1.9
Total assets	179.9	153.0
Claims and rebates payable	0	0
Accounts payable	15.5	4.6
Accrued expenses	33.0	10.7
Current maturities of long-term debt	0	0
Total current liabilities	48.5	15.3
Long-term debt	0	0
Intercompany	100.6	119.2
Other liabilities	2.0	4.7
Total stockholders' equity	28.8	13.8
Total liabilities and stockholders' equity	179.9	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	(6,678.3)	(6,382.2)
Intercompany	(3,757.0)	(3,214.0)
Goodwill	0	0
Other intangible assets, net	0	0
Other assets	0	0
Total assets	(10,435.3)	(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	(3,757.0)	(3,214.0)
Other liabilities	0	0
Total stockholders' equity	(6,678.3)	(6,382.2)
Total liabilities and stockholders' equity	$ (10,435.3)	$ (9,596.2)