Unsecured Borrowings - Unsecured Long-Term Borrowings after Hedging (Parenthetical) (Detail) |
Dec. 31, 2020 |
Dec. 31, 2019 |
|---|---|---|
| Debt Disclosure [Abstract] | ||
| Effective weighted average interest rates for unsecured long-term borrowings, after hedging - total | 2.01% | 2.87% |
| Effective weighted average interest rates for unsecured long-term borrowings, after hedging fixed rate obligations | 3.34% | 3.77% |
| Effective weighted average interest rates for unsecured long-term borrowings, after hedging - floating rate obligations | 1.70% | 2.48% |