Quarterly report pursuant to Section 13 or 15(d)

Debt - Senior Notes (Details)

v3.8.0.1
Debt - Senior Notes (Details) - USD ($)
 3 Months Ended
Nov. 19, 2014
Sep. 30, 2017
Sep. 30, 2016
Dec. 31, 2014
Jun. 30, 2017
Nov. 30, 2014
Oct. 31, 2014
Debt Instrument              
Cash dividends declared (in dollars per share)   $ 0.59 $ 0.52        
Unamortized discount   $ 2,798,000     $ 2,901,000    
Derivatives designated as hedging instruments | Portion of senior notes | Treasury lock | Senior notes | Cash flow hedge contracts              
Debt Instrument              
Notional amount of derivative             $ 1,000,000,000.00
Special cash dividend              
Debt Instrument              
Cash dividends declared (in dollars per share) $ 16.50            
Cash dividends       $ 2,760,000,000      
Senior notes              
Debt Instrument              
Face amount           $ 2,500,000,000.0  
Unamortized discount           4,000,000  
Redemption price   101.00%          
Fair value disclosure   $ 2,680,000,000     $ 2,670,000,000    
Senior notes | Standard & Poor's, BB plus Rating              
Debt Instrument              
Decrease in credit rating, interest rate adjustment (in bps)   0.25%          
Senior notes | Standard & Poor's, BB Rating              
Debt Instrument              
Decrease in credit rating, interest rate adjustment (in bps)   0.50%          
Senior notes | Standard & Poor's, BB- Rating              
Debt Instrument              
Decrease in credit rating, interest rate adjustment (in bps)   0.75%          
Senior notes | Standard & Poor's, B Plus or Below              
Debt Instrument              
Decrease in credit rating, interest rate adjustment (in bps)   1.00%          
Senior notes | Moody's, Ba1 Rating              
Debt Instrument              
Decrease in credit rating, interest rate adjustment (in bps)   0.25%          
Senior notes | Moody's, Ba2 Rating              
Debt Instrument              
Decrease in credit rating, interest rate adjustment (in bps)   0.50%          
Senior notes | Moody's, Ba3 Rating              
Debt Instrument              
Decrease in credit rating, interest rate adjustment (in bps)   0.75%          
Senior notes | Moody's, B1 Rating              
Debt Instrument              
Decrease in credit rating, interest rate adjustment (in bps)   1.00%          
Senior notes | Derivatives Not Designated as Hedging Instruments | 2018 Senior Notes | Treasury lock              
Debt Instrument              
Face amount           $ 750,000,000