1.0.0.3 false Consolidated Balance Sheets (USD $) In Millions false 1 $ false false Shares Standard http://www.xbrl.org/2003/instance shares xbrli 0 USD Standard http://www.xbrl.org/2003/iso4217 USD iso4217 0 false 2 $ false false Shares Standard http://www.xbrl.org/2003/instance shares xbrli 0 USD Standard http://www.xbrl.org/2003/iso4217 USD iso4217 0 3 ASSETS 1 us-gaap_AssetsAbstract us-gaap true na duration string No definition available. false false false false false true false false false 1 false false 0 0 false false 2 false false 0 0 false false No definition available. false 4 Cash and cash equivalents 2 us-gaap_CashAndCashEquivalentsAtCarryingValue us-gaap true debit instant monetary No definition available. false false false false false false false false false 1 true true 2528200000 2528.2 false false 2 true true 938400000 938.4 false false No definition available. No authoritative reference available. false 5 Short-term Investments 2 us-gaap_ShortTermInvestments us-gaap true debit instant monetary No definition available. false false false false false false false false false 1 false true 20100000 20.1 false false 2 false true 64000000 64.0 false false No definition available. No authoritative reference available. false 6 Manufacturer accounts receivable, net 2 mhs_ManufacturerAccountsReceivableNet mhs false debit instant monetary The total amount due to the entity within one year of the balance sheet date (or one operating cycle, if longer) representing... false false false false false false false false false 1 false true 1765500000 1765.5 false false 2 false true 1858900000 1858.9 false false The total amount due to the entity within one year of the balance sheet date (or one operating cycle, if longer) representing the billed and estimated unbilled amounts due from brand-name pharmaceutical manufacturers for earned rebates and other prescription services, as well as notes and loans receivable, and any other types of non client receivables, net of allowances established for the purpose of reducing such receivables to an amount that approximates their net realizable value. No authoritative reference available. false 7 Client accounts receivable, net 2 mhs_ClientAccountsReceivableNet mhs false debit instant monetary The total amount due to the entity within one year of the balance sheet date (or one operating cycle, if longer) from outside... false false false false false false false false false 1 false true 2063300000 2063.3 false false 2 false true 1680500000 1680.5 false false The total amount due to the entity within one year of the balance sheet date (or one operating cycle, if longer) from outside sources, primarily trade client accounts receivable net of allowances established for the purpose of reducing such receivables to an amount that approximates their net realizable value. Client accounts receivable includes billed and estimated unbilled receivables from clients, as well as a reduction for rebates and guarantees payable to clients when such are settled on a net basis in the form of an invoice credit. [Note: In cases where rebates and guarantees are settled with the client on a net basis, and the rebates and guarantees payable are greater than the corresponding client accounts balances, the net liability is reclassified to client rebates and guarantees payable. When these payables are settled in the form of a check or wire, they are recorded on a gross basis and the entire liability is reflected in client rebates and guarantees payable.] Client accounts receivable also includes premiums receivable from the Center for Medicare & Medicaid Services for the Medicare Part D Prescription Drug Program product offering and premiums from members. No authoritative reference available. false 8 Income taxes receivable 2 us-gaap_IncomeTaxesReceivable us-gaap true debit instant monetary No definition available. false false false false false false false false false 1 false true 198300000 198.3 false false 2 false true 213400000 213.4 false false No definition available. No authoritative reference available. false 9 Inventories, net 2 us-gaap_InventoryNet us-gaap true debit instant monetary No definition available. false false false false false false false false false 1 false true 1285300000 1285.3 false false 2 false true 1856500000 1856.5 false false No definition available. No authoritative reference available. false 10 Prepaid expenses and other current assets 2 mhs_PrepaidExpensesAndOtherCurrentAssets mhs false debit instant monetary Sum of the amounts paid in advance for capitalized costs that will be expensed with the passage of time or the occurrence of... false false false false false false false false false 1 false true 67100000 67.1 false false 2 false true 326600000 326.6 false false Sum of the amounts paid in advance for capitalized costs that will be expensed with the passage of time or the occurrence of a triggering event, and will be charged against earnings within one year or the normal operating cycle, if longer. Included in this is the aggregate carrying amount, as of the balance sheet date, of current assets not separately disclosed in the balance sheet due to materiality considerations. Current assets are expected to be realized or consumed within one year (or the normal operating cycle, if longer). No authoritative reference available. false 11 Deferred tax assets 2 us-gaap_DeferredTaxAssetsNetCurrent us-gaap true debit instant monetary No definition available. false false false false false false false false false 1 false true 230800000 230.8 false false 2 false true 159200000 159.2 false false No definition available. No authoritative reference available. true 12 Total current assets 2 us-gaap_AssetsCurrent us-gaap true debit instant monetary No definition available. false false false false false false false false false 1 false true 8158600000 8158.6 false false 2 false true 7097500000 7097.5 false false No definition available. No authoritative reference available. false 13 Property and equipment, net 2 us-gaap_PropertyPlantAndEquipmentNet us-gaap true debit instant monetary No definition available. false false false false false false false false false 1 false true 912500000 912.5 false false 2 false true 854100000 854.1 false false No definition available. No authoritative reference available. false 14 Goodwill 2 us-gaap_Goodwill us-gaap true debit instant monetary No definition available. false false false false false false false false false 1 false true 6333000000 6333.0 false false 2 false true 6331400000 6331.4 false false No definition available. No authoritative reference available. false 15 Intangible assets, net 2 us-gaap_IntangibleAssetsNetExcludingGoodwill us-gaap true debit instant monetary No definition available. false false false false false false false false false 1 false true 2428800000 2428.8 false false 2 false true 2666400000 2666.4 false false No definition available. No authoritative reference available. false 16 Other noncurrent assets 2 us-gaap_OtherAssetsNoncurrent us-gaap true debit instant monetary No definition available. false false false false false false false false false 1 false true 82600000 82.6 false false 2 false true 61500000 61.5 false false No definition available. No authoritative reference available. true 17 Total assets 2 us-gaap_Assets us-gaap true debit instant monetary No definition available. false false false false false false false false false 1 false true 17915500000 17915.5 false false 2 false true 17010900000 17010.9 false false No definition available. No authoritative reference available. true 18 LIABILITIES AND STOCKHOLDERS' EQUITY 1 us-gaap_LiabilitiesAndStockholdersEquityAbstract us-gaap true na duration string No definition available. false false false false false true false false false 1 false false 0 0 false false 2 false false 0 0 false false No definition available. false 19 Claims and other accounts payable 2 us-gaap_AccountsPayableCurrent us-gaap true credit instant monetary No definition available. false false false false false false false false false 1 false true 3506400000 3506.4 false false 2 false true 2878900000 2878.9 false false No definition available. No authoritative reference available. false 20 Client rebates and guarantees payable 2 mhs_ClientRebatesAndGuaranteesPayable mhs false credit instant monetary Carrying value as of the balance sheet date of liabilities incurred, due within one year, for certain rebates and guarantees... false false false false false false false false false 1 false true 2106900000 2106.9 false false 2 false true 1658700000 1658.7 false false Carrying value as of the balance sheet date of liabilities incurred, due within one year, for certain rebates and guarantees payable. In cases where rebates and guarantees payable are settled on a net basis, and the rebates and guarantees payable are greater than the corresponding client accounts balances, the net liability is reclassified to client rebates and guarantees payable. When these payables are settled in the form of a check or wire, they are recorded on a gross basis and the entire liability is reflected in client rebates and guarantees payable. [Note: When these payables are settled on a net basis in the form of an invoice credit they are recorded as a reduction to Client accounts receivable, net.] No authoritative reference available. false 21 Accrued expenses and other current liabilities 2 mhs_AccruedExpensesAndOtherCurrentLiabilities mhs false credit instant monetary Carrying value as of the balance sheet date of obligations incurred and payable, pertaining to costs that are statutory in... false false false false false false false false false 1 false true 718600000 718.6 false false 2 false true 660400000 660.4 false false Carrying value as of the balance sheet date of obligations incurred and payable, pertaining to costs that are statutory in nature, are incurred on contractual obligations, or accumulate over time and for which invoices have not yet been received or will not be rendered. Examples include taxes, interest, rent and utilities. Used to reflect the current portion of the liabilities (due within one year or within the normal operating cycle if longer). Other current liabilities are defined as the aggregate carrying amount, as of the balance sheet date, of current obligations not separately disclosed in the balance sheet due to materiality considerations. Current liabilities are expected to be paid within one year (or the normal operating cycle, if longer). No authoritative reference available. false 22 Short-term debt 2 us-gaap_ShortTermBankLoansAndNotesPayable us-gaap true credit instant monetary No definition available. false false false false false false false false false 1 false true 15800000 15.8 false false 2 false true 600000000 600.0 false false No definition available. No authoritative reference available. true 23 Total current liabilities 2 us-gaap_LiabilitiesCurrent us-gaap true credit instant monetary No definition available. false false false false false false false false false 1 false true 6347700000 6347.7 false false 2 false true 5798000000 5798.0 false false No definition available. No authoritative reference available. false 24 Long-term debt, net 2 us-gaap_LongTermDebtNoncurrent us-gaap true credit instant monetary No definition available. false false false false false false false false false 1 false true 4000100000 4000.1 false false 2 false true 4002900000 4002.9 false false No definition available. No authoritative reference available. false 25 Deferred tax liabilities 2 us-gaap_DeferredTaxLiabilitiesNoncurrent us-gaap true credit instant monetary No definition available. false false false false false false false false false 1 false true 958800000 958.8 false false 2 false true 1065300000 1065.3 false false No definition available. No authoritative reference available. false 26 Other noncurrent liabilities 2 us-gaap_OtherLiabilitiesNoncurrent us-gaap true credit instant monetary No definition available. false false false false false false false false false 1 false true 221700000 221.7 false false 2 false true 186800000 186.8 false false No definition available. No authoritative reference available. true 27 Total liabilities 2 us-gaap_Liabilities us-gaap true credit instant monetary No definition available. false false false false false false false false false 1 false true 11528300000 11528.3 false false 2 false true 11053000000 11053.0 false false No definition available. No authoritative reference available. true 29 Stockholders' equity: 2 us-gaap_StockholdersEquityAbstract us-gaap true na duration string No definition available. false false false false false true false false false 1 false false 0 0 false false 2 false false 0 0 false false No definition available. false 30 Preferred stock, par value $0.01-authorized: 10,000,000 shares; issued and outstanding: 0 3 us-gaap_PreferredStockValue us-gaap true credit instant monetary No definition available. false false false false false false false false false 1 false true 0 0 false false 2 false true 0 0 false false No definition available. No authoritative reference available. false 31 Common stock, par value $0.01-authorized: 2,000,000,000 shares; issued: 660,846,867 shares at December 26, 2009 and 652,386,763 shares at December 27, 2008 3 us-gaap_CommonStockValue us-gaap true credit instant monetary No definition available. false false false false false false false false false 1 false true 6600000 6.6 false false 2 false true 6500000 6.5 false false No definition available. No authoritative reference available. false 32 Accumulated other comprehensive loss 3 us-gaap_AccumulatedOtherComprehensiveIncomeLossNetOfTax us-gaap true credit instant monetary No definition available. false false false false false false false false false 1 false true -44200000 -44.2 false false 2 false true -63800000 -63.8 false false No definition available. No authoritative reference available. false 33 Additional paid-in capital 3 us-gaap_AdditionalPaidInCapitalCommonStock us-gaap true credit instant monetary No definition available. false false false false false false false false false 1 false true 8156700000 8156.7 false false 2 false true 7788900000 7788.9 false false No definition available. No authoritative reference available. false 34 Retained earnings 3 us-gaap_RetainedEarningsAccumulatedDeficit us-gaap true credit instant monetary No definition available. false false false false false false false false false 1 false true 5209600000 5209.6 false false 2 false true 3929300000 3929.3 false false No definition available. No authoritative reference available. true 35 Stockholders' equity before treasury stock 3 mhs_StockholdersEquityBeforeTreasuryStock mhs false credit instant monetary Subtotal of stockholders' equity before treasury stock false false false false false false false false false 1 false true 13328700000 13328.7 false false 2 false true 11660900000 11660.9 false false Subtotal of stockholders' equity before treasury stock No authoritative reference available. false 36 Treasury stock, at cost: 186,353,868 shares at December 26, 2009 and 159,061,394 shares at December 27, 2008 3 us-gaap_TreasuryStockValue us-gaap true debit instant monetary No definition available. false false false false false false false false false 1 false true -6941500000 -6941.5 false false 2 false true -5703000000 -5703.0 false false No definition available. No authoritative reference available. true 37 Total stockholders' equity 3 us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest us-gaap true credit instant monetary No definition available. false false false false false false false false false 1 false true 6387200000 6387.2 false false 2 false true 5957900000 5957.9 false false No definition available. No authoritative reference available. true 38 Total liabilities and stockholders' equity 3 us-gaap_LiabilitiesAndStockholdersEquity us-gaap true credit instant monetary No definition available. false false false false false false false false false 1 true true 17915500000 17915.5 false false 2 true true 17010900000 17010.9 false false No definition available. No authoritative reference available. true false 2 35 false HundredThousands UnKnown UnKnown false true