v2.4.1.9
Shareholders' Equity (Details) (USD $)
 3 Months Ended 12 Months Ended
Dec. 31, 2014
Sep. 30, 2014
Jun. 30, 2014
Mar. 31, 2014
Dec. 31, 2013
Sep. 30, 2013
Jun. 30, 2013
Mar. 31, 2013
Dec. 31, 2014
Dec. 31, 2013
Dec. 31, 2012
Dec. 31, 2000
Oct. 31, 2013
Treasury Stock, Value, Acquired, Cost Method                 $ 800,000,000us-gaap_TreasuryStockValueAcquiredCostMethod $ 1,600,000,000us-gaap_TreasuryStockValueAcquiredCostMethod $ 819,200,000us-gaap_TreasuryStockValueAcquiredCostMethod    
Stockholders' Equity, Including Portion Attributable to Noncontrolling Interest 15,388,100,000us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest       17,640,700,000us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest       15,388,100,000us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest 17,640,700,000us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest      
Common stock shares in treasury, shares in thousands 810,000us-gaap_TreasuryStockShares       833,000us-gaap_TreasuryStockShares       810,000us-gaap_TreasuryStockShares 833,000us-gaap_TreasuryStockShares      
Net income 428,500,000us-gaap_NetIncomeLoss 500,600,000us-gaap_NetIncomeLoss 733,500,000us-gaap_NetIncomeLoss 727,900,000us-gaap_NetIncomeLoss 727,500,000us-gaap_NetIncomeLoss 1,203,100,000us-gaap_NetIncomeLoss 1,206,200,000us-gaap_NetIncomeLoss 1,548,000,000us-gaap_NetIncomeLoss 2,390,500,000us-gaap_NetIncomeLoss 4,684,800,000us-gaap_NetIncomeLoss 4,088,600,000us-gaap_NetIncomeLoss    
Treasury Stock, Retired, Cost Method, Amount                 0us-gaap_TreasuryStockRetiredCostMethodAmount 0us-gaap_TreasuryStockRetiredCostMethodAmount (100,000)us-gaap_TreasuryStockRetiredCostMethodAmount    
Preferred Stock, Shares Authorized 5,000,000us-gaap_PreferredStockSharesAuthorized               5,000,000us-gaap_PreferredStockSharesAuthorized        
Preferred Stock, Shares Issued 0us-gaap_PreferredStockSharesIssued       0us-gaap_PreferredStockSharesIssued       0us-gaap_PreferredStockSharesIssued 0us-gaap_PreferredStockSharesIssued      
Common Stock, Shares Held in Employee Trust, Shares 50,000,000us-gaap_CommonStockSharesHeldInEmployeeTrustShares       50,000,000us-gaap_CommonStockSharesHeldInEmployeeTrustShares       50,000,000us-gaap_CommonStockSharesHeldInEmployeeTrustShares 50,000,000us-gaap_CommonStockSharesHeldInEmployeeTrustShares      
Employee benefit trust 3,013,200,000us-gaap_CommonStockSharesHeldInEmployeeTrust       3,013,200,000us-gaap_CommonStockSharesHeldInEmployeeTrust       3,013,200,000us-gaap_CommonStockSharesHeldInEmployeeTrust 3,013,200,000us-gaap_CommonStockSharesHeldInEmployeeTrust      
Other comprehensive income (loss)                 (1,989,100,000)us-gaap_OtherComprehensiveIncomeLossNetOfTax 1,794,400,000us-gaap_OtherComprehensiveIncomeLossNetOfTax 61,500,000us-gaap_OtherComprehensiveIncomeLossNetOfTax    
Allocated Share-based Compensation Expense                 156,000,000us-gaap_AllocatedShareBasedCompensationExpense 144,900,000us-gaap_AllocatedShareBasedCompensationExpense 141,500,000us-gaap_AllocatedShareBasedCompensationExpense    
Issued shares, shares in thousands 1,111,437,000us-gaap_CommonStockSharesIssued       1,117,628,000us-gaap_CommonStockSharesIssued       1,111,437,000us-gaap_CommonStockSharesIssued 1,117,628,000us-gaap_CommonStockSharesIssued      
Additional Paid-in Capital [Member]                          
Treasury Stock, Retired, Cost Method, Amount                           
Retained Earnings [Member]                          
Net income                 2,390,500,000us-gaap_NetIncomeLoss
/ us-gaap_StatementEquityComponentsAxis
= us-gaap_RetainedEarningsMember		 4,684,800,000us-gaap_NetIncomeLoss
/ us-gaap_StatementEquityComponentsAxis
= us-gaap_RetainedEarningsMember		 4,088,600,000us-gaap_NetIncomeLoss
/ us-gaap_StatementEquityComponentsAxis
= us-gaap_RetainedEarningsMember		    
Treasury Stock, Retired, Cost Method, Amount                 (792,100,000)us-gaap_TreasuryStockRetiredCostMethodAmount
/ us-gaap_StatementEquityComponentsAxis
= us-gaap_RetainedEarningsMember		 (1,677,800,000)us-gaap_TreasuryStockRetiredCostMethodAmount
/ us-gaap_StatementEquityComponentsAxis
= us-gaap_RetainedEarningsMember		 (711,700,000)us-gaap_TreasuryStockRetiredCostMethodAmount
/ us-gaap_StatementEquityComponentsAxis
= us-gaap_RetainedEarningsMember		    
Treasury Stock [Member]                          
Treasury Stock, Value, Acquired, Cost Method                 800,000,000us-gaap_TreasuryStockValueAcquiredCostMethod
/ us-gaap_StatementEquityComponentsAxis
= us-gaap_TreasuryStockMember		 1,600,000,000us-gaap_TreasuryStockValueAcquiredCostMethod
/ us-gaap_StatementEquityComponentsAxis
= us-gaap_TreasuryStockMember		 819,200,000us-gaap_TreasuryStockValueAcquiredCostMethod
/ us-gaap_StatementEquityComponentsAxis
= us-gaap_TreasuryStockMember		    
Treasury Stock, Retired, Cost Method, Amount                 (800,000,000)us-gaap_TreasuryStockRetiredCostMethodAmount
/ us-gaap_StatementEquityComponentsAxis
= us-gaap_TreasuryStockMember		 (1,698,100,000)us-gaap_TreasuryStockRetiredCostMethodAmount
/ us-gaap_StatementEquityComponentsAxis
= us-gaap_TreasuryStockMember		 (721,100,000)us-gaap_TreasuryStockRetiredCostMethodAmount
/ us-gaap_StatementEquityComponentsAxis
= us-gaap_TreasuryStockMember		    
Treasury Stock, Shares, Retired                 (12,579,000)us-gaap_TreasuryStockSharesRetired
/ us-gaap_StatementEquityComponentsAxis
= us-gaap_TreasuryStockMember		 (32,406,000)us-gaap_TreasuryStockSharesRetired
/ us-gaap_StatementEquityComponentsAxis
= us-gaap_TreasuryStockMember		 (14,912,000)us-gaap_TreasuryStockSharesRetired
/ us-gaap_StatementEquityComponentsAxis
= us-gaap_TreasuryStockMember		    
2000 Share Repurchase Program [Member]                          
Treasury Stock, Value, Acquired, Cost Method                     419,200,000us-gaap_TreasuryStockValueAcquiredCostMethod
/ us-gaap_StatementEquityComponentsAxis
= lly_A2000ShareRepurchaseProgramMember		    
Stock Repurchase Program, Authorized Amount                       3,000,000,000us-gaap_StockRepurchaseProgramAuthorizedAmount1
/ us-gaap_StatementEquityComponentsAxis
= lly_A2000ShareRepurchaseProgramMember		  
2012 Share Repurchase Program [Member]                          
Treasury Stock, Value, Acquired, Cost Method                   1,100,000,000us-gaap_TreasuryStockValueAcquiredCostMethod
/ us-gaap_StatementEquityComponentsAxis
= lly_A2012ShareRepurchaseProgramMember		 400,000,000us-gaap_TreasuryStockValueAcquiredCostMethod
/ us-gaap_StatementEquityComponentsAxis
= lly_A2012ShareRepurchaseProgramMember		    
Stock Repurchase Program, Authorized Amount                     1,500,000,000us-gaap_StockRepurchaseProgramAuthorizedAmount1
/ us-gaap_StatementEquityComponentsAxis
= lly_A2012ShareRepurchaseProgramMember		    
2013 Share Repurchase Program [Member]                          
Treasury Stock, Value, Acquired, Cost Method                 800,000,000us-gaap_TreasuryStockValueAcquiredCostMethod
/ us-gaap_StatementEquityComponentsAxis
= lly_A2013ShareRepurchaseProgramMember		 500,000,000us-gaap_TreasuryStockValueAcquiredCostMethod
/ us-gaap_StatementEquityComponentsAxis
= lly_A2013ShareRepurchaseProgramMember		      
Stock Repurchase Program, Authorized Amount                         5,000,000,000us-gaap_StockRepurchaseProgramAuthorizedAmount1
/ us-gaap_StatementEquityComponentsAxis
= lly_A2013ShareRepurchaseProgramMember
Stock Repurchase Program, Remaining Authorized Repurchase Amount $ 3,700,000,000us-gaap_StockRepurchaseProgramRemainingAuthorizedRepurchaseAmount1
/ us-gaap_StatementEquityComponentsAxis
= lly_A2013ShareRepurchaseProgramMember		               $ 3,700,000,000us-gaap_StockRepurchaseProgramRemainingAuthorizedRepurchaseAmount1
/ us-gaap_StatementEquityComponentsAxis
= lly_A2013ShareRepurchaseProgramMember