Long-Term Debt - Additional Information (Detail) - USD ($) $ in Millions |
3 Months Ended | 6 Months Ended | |
---|---|---|---|
Mar. 31, 2019 |
Jun. 30, 2019 |
Jun. 30, 2018 |
|
Debt Disclosure [Abstract] | |||
Interest paid, net of amounts capitalized | $ 176 | $ 144 | |
Maximum borrowing capacity under credit facility | 4,500 | ||
Senior Notes | Series BB Notes | |||
Debt Instrument [Line Items] | |||
Senior notes, face amount | $ 300 | 300 | |
Senior Notes | Series CC Notes | |||
Debt Instrument [Line Items] | |||
Senior notes, face amount | $ 550 | $ 550 | |
Interest rate | 3.60% | 3.60% | |
Senior Notes | Series BB and Series CC Notes | |||
Debt Instrument [Line Items] | |||
Proceeds from debt offering | $ 841 | ||
LIBOR | Senior Notes | Series BB Notes | |||
Debt Instrument [Line Items] | |||
Variable interest rate | 0.65% |