Borrowings - Breakdown of FHLB Advances Outstanding (Details) - USD ($) $ in Millions	Mar. 31, 2020	Dec. 31, 2019
Federal Home Loan Bank, Advances, Branch of FHLB Bank [Line Items]
Short-term amount	$ 5,841	$ 4,165
Federal Home Loan Bank, Advances, General Debt Obligations, Disclosures, Interest Rate at Period End	1.19%	1.45%
Long-term Federal Home Loan Bank fixed rate advances	$ 1,000	$ 650
Total	6,841	4,815
Current portion of fixed rate advances	0	0
Short-term fixed rate term advances
Federal Home Loan Bank, Advances, Branch of FHLB Bank [Line Items]
Short-term amount	$ 5,336	$ 3,695
Federal Home Loan Bank, Advances, General Debt Obligations, Disclosures, Interest Rate at Period End	0.24%	1.61%
Other short-term borrowings
Federal Home Loan Bank, Advances, Branch of FHLB Bank [Line Items]
Short-term amount	$ 505	$ 470
Federal Home Loan Bank, Advances, General Debt Obligations, Disclosures, Interest Rate at Period End	0.20%	1.64%

Amount of borrowings as of the balance sheet date from the Federal Home Loan Bank, which are primarily used to cover shortages in the required reserve balance and liquidity shortages.

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The current portion of Federal Home Loan Bank borrowings initially due beyond one year or beyond the normal operating cycle if longer.

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States the interest rate applicable to Federal Home Loan Bank advances outstanding as of the Balance Sheet date.

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Including both current and noncurrent portions, Federal Home Loan Bank borrowings initially due beyond one year or beyond the normal operating cycle if longer.

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Amount of advances from Federal Home Loan Bank (FHLBank) maturing in the next fiscal year following the latest fiscal year. Excludes interim and annual periods when interim periods are reported on a rolling approach, from latest balance sheet date.

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