Basis of Presentation - Additional Information (Detail) $ in Millions |
Jan. 01, 2018
USD ($)
|
|---|---|
| Recognition of additional provisions for impairment of receivables under the expected loss model [member] | |
| Disclosure of basis of preparation of financial statements [line items] | |
| Increase (Decrease) in Equity | $ (83) |
| Changing the measurement basis from amortised cost to fair value [member] | |
| Disclosure of basis of preparation of financial statements [line items] | |
| Increase (Decrease) in Equity | $ 33 |