Related Party Transactions - SLK Global Solutions Private Limited and CDC Investments (Details) - USD ($) $ in Millions	12 Months Ended
Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Related Party Transactions
Loans to related parties	$ 67	$ 49
SLK Global
Related Party Transactions
Ownership percentage	49.00%
Dividend on equity method investment	$ 1	1
Investment	26	26
Service fee paid	27	22	$ 21
SLK Global \| Other noninterest income
Related Party Transactions
Revenue from related Parties	5	3	$ 2
CDC
Related Party Transactions
Loans to related parties	18	12
Related party, deposit liabilities	63	116
CDC \| Unfunded Commitment
Related Party Transactions
Due to other related parties	$ 39	$ 21
Fifth Third Mauritius Holdings Limited
Related Party Transactions
Ownership percentage	100.00%

For an unclassified balance sheet, amounts due from related parties including affiliates, employees, joint ventures, officers and stockholders, immediate families thereof, and pension funds.

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