Unsecured Borrowings - Unsecured Long-Term Borrowings (Parenthetical) (Detail) - Unsecured Debt [Member]	Sep. 30, 2020	Dec. 31, 2019
U.S. Dollar [Member] | Minimum [Member]
Debt Instrument [Line Items]
Fixed interest rate debt obligations interest rates range	2.00%	2.00%
U.S. Dollar [Member] | Maximum [Member]
Debt Instrument [Line Items]
Fixed interest rate debt obligations interest rates range	9.30%	10.04%
U.S. Dollar [Member] | Weighted Average [Member]
Debt Instrument [Line Items]
Fixed interest rate debt obligations interest rates range	4.18%	3.82%
Non-U.S. Dollar [Member] | Minimum [Member]
Debt Instrument [Line Items]
Fixed interest rate debt obligations interest rates range	0.13%	0.13%
Non-U.S. Dollar [Member] | Maximum [Member]
Debt Instrument [Line Items]
Fixed interest rate debt obligations interest rates range	13.00%	13.00%
Non-U.S. Dollar [Member] | Weighted Average [Member]
Debt Instrument [Line Items]
Fixed interest rate debt obligations interest rates range	2.32%	2.33%