Annual report pursuant to Section 13 and 15(d)

Debt - Interest Expense (Details)

v3.8.0.1
Debt - Interest Expense (Details) - USD ($)
$ in Millions
 12 Months Ended
Dec. 31, 2017
Dec. 31, 2016
Dec. 31, 2015
Debt Instrument [Line Items]      
Total interest cost $ 1,526 $ 1,301 $ 997
Capitalized interest (779) (813) (675)
Total interest expense, net 747 488 322
Convertible Debt [Member]      
Debt Instrument [Line Items]      
Interest per contractual rate 219 202 146
Amortization of debt discount 29 31 28
Amortization of debt issuance costs 7 5 3
Total interest cost 255 238 177
Debt Excluding Convertible Debt [Member]      
Debt Instrument [Line Items]      
Total interest cost $ 1,271 $ 1,063 $ 820