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Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

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Amount of paid and unpaid cash, stock, and paid-in-kind (PIK) dividends declared, for example, but not limited to, common and preferred stock.

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Amount of expected credit loss for credit exposure on off-balance-sheet commitment, including but not limited to, loan commitment, standby letter of credit, financial guarantee not accounted for as insurance. Excludes off-balance sheet credit exposure accounted for as insurance and instrument accounted for under derivatives and hedging.

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Regulatory Capital - Additional Information (Details)		3 Months Ended
Regulatory Capital - Additional Information (Details)	Jan. 01, 2020 USD ($)	Mar. 31, 2020 USD ($)	Mar. 31, 2019 USD ($)	Dec. 31, 2019 USD ($)	Dec. 31, 2018 USD ($)
Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items]
Allowance for credit losses on loans and leases	$ 441,912,000	$ 1,673,324,000	$ 358,325,000	$ 441,912,000	$ 341,121,000
Allowance for credit losses on unfunded commitments	2,481,000
Reduction to retained earnings	$ 1,850,512,000
Dividends		$ 541,000,000	$ 85,000,000
Accounting Standards Update 2016-13
Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items]
Period of deferment	2
Amount deferred	25.00%
Allowance for credit losses on loans and leases	$ 1,100,000,000
Allowance for credit losses on unfunded commitments	116,000,000
Deferred tax assets	306,000,000
Reduction to retained earnings	$ 953,000,000