Fair value of financial instruments - Carrying value and an estimated fair value (Details) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Disclosure of Fair value of financial instruments [Line Items]
Cash and deposits on banks	$ 863,812	$ 1,178,170
Securities at amortized cost (1)	165,564	75,271
Loans at amortized cost, net (2)	4,896,647	5,823,333
Customers' liabilities under acceptances	74,366	115,682
Investment properties	3,214	3,494
Deposits	3,140,875	2,893,555
Securities sold under repurchase agreements	10,663	40,530
Borrowings and debt, net (3)	1,985,070	3,138,310	$ 3,518,446	$ 2,211,567
Acceptance outstanding	74,366	115,682
Not measured at fair value in statement of financial position but for which fair value is disclosed [member]
Disclosure of Fair value of financial instruments [Line Items]
Cash and deposits on banks	863,812	1,178,170
Securities at amortized cost (1)	165,564	75,271
Loans at amortized cost, net (2)	4,891,698	5,823,333
Customers' liabilities under acceptances	74,366	115,682
Investment properties	3,214	3,494
Deposits	3,140,875	2,893,555
Securities sold under repurchase agreements	10,663	40,530
Borrowings and debt, net (3)	1,966,271	3,118,396
Acceptance outstanding	74,366	115,682
At fair value [member]
Disclosure of Fair value of financial instruments [Line Items]
Cash and deposits on banks	863,812	1,178,170
Securities at amortized cost (1)	168,110	75,724
Loans at amortized cost, net (2)	4,972,599	6,162,885
Customers' liabilities under acceptances	74,366	115,682
Investment properties	3,214	3,494
Deposits	3,140,875	2,893,555
Securities sold under repurchase agreements	10,663	40,530
Borrowings and debt, net (3)	1,989,719	3,126,333
Acceptance outstanding	74,366	115,682
Level 1 of fair value hierarchy [member] \| Not measured at fair value in statement of financial position but for which fair value is disclosed [member]
Disclosure of Fair value of financial instruments [Line Items]
Cash and deposits on banks	0	0
Securities at amortized cost (1)	0	0
Loans at amortized cost, net (2)	0	0
Deposits	0	0
Level 1 of fair value hierarchy [member] \| At fair value [member]
Disclosure of Fair value of financial instruments [Line Items]
Customers' liabilities under acceptances	0	0
Investment properties	0	0
Securities sold under repurchase agreements	0	0
Borrowings and debt, net (3)	0	0
Acceptance outstanding	0	0
Level 2 of fair value hierarchy [member] \| Not measured at fair value in statement of financial position but for which fair value is disclosed [member]
Disclosure of Fair value of financial instruments [Line Items]
Cash and deposits on banks	863,812	1,178,170
Securities at amortized cost (1)	157,698	56,914
Loans at amortized cost, net (2)	4,972,599	6,101,040
Deposits	3,140,875	2,893,555
Level 2 of fair value hierarchy [member] \| At fair value [member]
Disclosure of Fair value of financial instruments [Line Items]
Customers' liabilities under acceptances	74,366	115,682
Securities sold under repurchase agreements	10,663	40,530
Borrowings and debt, net (3)	1,989,719	3,126,333
Acceptance outstanding	74,366	115,682
Level 3 \| Not measured at fair value in statement of financial position but for which fair value is disclosed [member]
Disclosure of Fair value of financial instruments [Line Items]
Cash and deposits on banks	0	0
Securities at amortized cost (1)	10,412	18,810
Loans at amortized cost, net (2)	0	61,845
Deposits	0	0
Level 3 \| At fair value [member]
Disclosure of Fair value of financial instruments [Line Items]
Customers' liabilities under acceptances	0	0
Investment properties	3,214	3,494
Securities sold under repurchase agreements	0	0
Borrowings and debt, net (3)	0	0
Acceptance outstanding	$ 0	$ 0

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- Definition

Amounts receivable from customers on short-term negotiable time drafts drawn on and accepted by the institution (also known as banker's acceptance transactions) that are outstanding on the reporting date.

+ References

No definition available.

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- Definition

The amount of outstanding funds that the entity is obligated to repay.

+ References

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The amount of cash on hand and demand deposits, along with short-term, highly liquid investments that are readily convertible to known amounts of cash and that are subject to an insignificant risk of changes in value. [Refer: Cash; Cash equivalents]

+ References

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The amount of deposit liabilities from customers held by the entity.

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The amount of financial assets at amortised cost. The amortised cost is the amount at which financial assets are measured at initial recognition minus principal repayments, plus or minus the cumulative amortisation using the effective interest method of any difference between that initial amount and the maturity amount, and adjusted for any impairment. [Refer: Financial assets]

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The amount of property (land or a building - or part of a building - or both) held (by the owner or by the lessee as a right-of-use asset) to earn rentals or for capital appreciation or both, rather than for: (a) use in the production or supply of goods or services or for administrative purposes; or (b) sale in the ordinary course of business.

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The amount of loans and advances the entity has made to customers.

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The amount of non-derivative financial assets with fixed or determinable payments that are not quoted in an active market, other than: (a) those that the entity intends to sell immediately or in the near term, which shall be classified as held for trading, and those that the entity, upon initial recognition, designates as at fair value through profit or loss; (b) those that the entity, upon initial recognition, designates as available for sale; or (c) those for which the holder may not recover substantially all of its initial investment, other than because of credit deterioration, which shall be classified as available for sale. An interest acquired in a pool of assets that are not loans or receivables (for example, an interest in a mutual fund or a similar fund) is not a loan or receivable. [Refer: Derivative financial assets]

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The amount of instruments sold with the intent to reacquire in repurchase agreements and cash collateral on securities lent.

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