Stock-Based Compensation (Tables)
 3 Months Ended
Mar. 31, 2015
Stock-Based Compensation  
Stock-Based Compensation Expense
Stock-Based Compensation Expense      
       
  Three months ended
  March 31,
(Millions) 2015 2014
Cost of sales  $ 23 $ 22
Selling, general and administrative expenses    88   77
Research, development and related expenses    27   23
       
Stock-based compensation expenses  $ 138 $ 122
       
Income tax benefits  $ (47) $ (40)
       
Stock-based compensation expenses, net of tax  $ 91 $ 82
Stock Option Activity
The following table summarizes stock option activity during the three months ended March 31, 2015:
             
Stock Option Program          
  Number of Options Weighted Average Exercise Price Weighted Average Remaining Contractual Life (months) Aggregate Intrinsic Value (millions)
Under option —          
 January 1   39,235,557 $ 90.38     
 Granted:          
  Annual   5,529,615   165.91     
 Exercised   (3,164,169)   84.03     
 Canceled   (25,786)   130.40     
 March 31 41,575,217 $ 100.89 72 $ 2,669
Options exercisable           
 March 31 30,089,556 $ 85.71 58 $ 2,384
Stock Option Assumptions
  Annual 
Stock Option Assumptions 2015 
Exercise price  $165.94 
Risk-free interest rate   1.5%
Dividend yield   2.5%
Expected volatility   20.1%
Expected life (months)   76 
Black-Scholes fair value  $23.98 
Restricted Stock Units and Restricted Stock Activity
Restricted Stock Units and Restricted Stock     
       Weighted Average
Restricted Stock Units and Number of Grant Date
Restricted StockAwardsFair Value
Nonvested balance —     
 As of January 1   2,817,786 $ 104.41
  Granted:     
   Annual   671,204   165.86
   Other   6,435   163.01
  Vested   (931,210)   90.38
  Forfeited   (12,372)   104.19
 As of March 31  2,551,843 $ 125.84
Performance Shares Activity
       Weighted Average
     Number of Grant Date
Performance SharesAwardsFair Value
Undistributed balance —     
 As of January 1   1,099,752 $ 102.65
  Granted   220,439   159.32
  Distributed   (323,717)   83.07
  Performance change   (18,723)   122.45
  Forfeited   (2,682)   100.23
 As of March 31   975,069 $ 121.59