v3.19.3.a.u2
Debt - 2019 Notes, 2021 Notes, Bond Hedges and Warrant Transactions - Additional Information (Detail)
1 Months Ended 3 Months Ended 12 Months Ended
Apr. 30, 2014
USD ($)
$ / shares
Mar. 31, 2014
USD ($)
d
$ / shares
shares
Mar. 31, 2019
USD ($)
Dec. 31, 2019
USD ($)
Dec. 31, 2017
USD ($)
Debt Instrument [Line Items]          
Proceeds from issuance of warrants       $ 174,000,000 $ 53,000,000
Senior Notes [Member]          
Debt Instrument [Line Items]          
Payment for purchase of common stock | shares   3,800,000      
Conversion price per share | $ / shares   $ 359.87      
Hedge transactions   $ 604,000,000      
Proceeds from issuance of warrants   389,000,000      
Senior Notes [Member] | 0.25% Convertible Senior Notes due in 2019 ("2019 Notes") [Member]          
Debt Instrument [Line Items]          
Principal amount of convertible senior notes $ 120,000,000 $ 800,000,000      
Interest Rate   0.25%      
Contractual Maturity Date   2019-03      
Proceeds from convertible senior notes, net of underwriting discounts and issuance costs $ 906,000,000        
Debt conversion, converted instrument, amount   $ 188,000,000      
Debt instrument, effective interest rate   4.89%      
Shares issued under warrants | shares   2,600,000      
Exercise price of warrant | $ / shares   $ 512.66      
Repayment of aggregate principal amount     $ 920,000,000    
Senior Notes [Member] | 0.25% Convertible Senior Notes due in 2019 ("2019 Notes") [Member] | Minimum [Member]          
Debt Instrument [Line Items]          
Conversion price per share | $ / shares $ 359.87        
Senior Notes [Member] | 0.25% Convertible Senior Notes due in 2019 ("2019 Notes") [Member] | Maximum [Member]          
Debt Instrument [Line Items]          
Conversion price per share | $ / shares $ 512.66        
Senior Notes [Member] | 1.25% Convertible Senior Notes due in 2021 ("2021 Notes") [Member]          
Debt Instrument [Line Items]          
Principal amount of convertible senior notes $ 180,000,000 $ 1,200,000,000      
Interest Rate   1.25%      
Contractual Maturity Date   2021-03      
Proceeds from convertible senior notes, net of underwriting discounts and issuance costs $ 1,360,000,000        
Debt conversion, converted instrument, amount   $ 369,000,000      
Debt instrument, effective interest rate   5.96%      
Shares issued under warrants | shares   3,800,000      
Exercise price of warrant | $ / shares   $ 560.64      
Debt instrument convertible, if-converted value in excess of principal       $ 224,000,000  
Senior Notes [Member] | 1.25% Convertible Senior Notes due in 2021 ("2021 Notes") [Member] | Minimum [Member]          
Debt Instrument [Line Items]          
Conversion price per share | $ / shares $ 359.87        
Senior Notes [Member] | 1.25% Convertible Senior Notes due in 2021 ("2021 Notes") [Member] | Maximum [Member]          
Debt Instrument [Line Items]          
Conversion price per share | $ / shares $ 560.64        
Senior Notes [Member] | 0.25% and 1.25% Convertible Senior Notes and Bond Hedge and Warrant Transactions [Member]          
Debt Instrument [Line Items]          
Convertible principal amount   $ 1,000      
Shares issued upon conversion of each $1000 principal amount | shares   2.7788      
Convertible notes, conversion price | $ / shares   $ 359.87      
Debt instrument convertible, percentage of conversion price   130.00%      
Product percentage of closing sale price of common stock   98.00%      
Percentage of repurchase price is equal to principal amount of convertible notes   100.00%      
Senior Notes [Member] | 0.25% and 1.25% Convertible Senior Notes and Bond Hedge and Warrant Transactions [Member] | One Hundred Thirty Percent Applicable Conversion Price [Member] | Minimum [Member]          
Debt Instrument [Line Items]          
Debt instrument convertible consecutive trading days | d   20      
Senior Notes [Member] | 0.25% and 1.25% Convertible Senior Notes and Bond Hedge and Warrant Transactions [Member] | One Hundred Thirty Percent Applicable Conversion Price [Member] | Maximum [Member]          
Debt Instrument [Line Items]          
Debt instrument convertible trading days | d   30      
Senior Notes [Member] | 0.25% and 1.25% Convertible Senior Notes and Bond Hedge and Warrant Transactions [Member] | Ninety Eight Percent Applicable Conversion Price [Member]          
Debt Instrument [Line Items]          
Debt instrument convertible consecutive trading days | d   5