Borrowed Funds - Summary of Borrowed Funds (Details) - USD ($) $ in Thousands	Sep. 30, 2020	Dec. 31, 2019
Debt Disclosure [Abstract]
Securities sold under agreements to repurchase	$ 132,652	$ 103,515
Federal funds purchased	0	160,000
FHLB advances	1,824,528	1,395,243
Total borrowed funds	$ 1,957,180	$ 1,658,758

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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Amount of short term borrowing where a bank borrows, at the federal funds rate, from another bank.

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Amount, after the effects of master netting arrangements, of funds outstanding borrowed in the form of a security repurchase agreement between the entity and another party for the sale and repurchase of identical or substantially the same securities at a date certain for a specified price. Includes liabilities not subject to a master netting arrangement and not elected to be offset.

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Reflects the total carrying amount as of the balance sheet date of debt having initial terms less than one year or the normal operating cycle, if longer.

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