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Financing Receivable, Collateral Dependent, Amount

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Financing Receivable, Credit Quality, Baseline Economic Forecast Percentage

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Financing Receivable, Previously Modification, Number of Contracts, Recovered

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- Definition

Financing Receivable, Troubled Debt Restructuring, Previously Modified, Recovered

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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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- Definition

Amount of allowance for credit loss on financing receivable. Excludes allowance for financing receivable covered under loss sharing agreement.

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Amount of writeoff of financing receivable, charged against allowance for credit loss.

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Amount of fee received for commitment to originate or purchase financing receivable where likelihood of commitment being exercised is remote. Excludes financing receivable covered under loss sharing agreement.

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Number of financing receivables that have been modified by troubled debt restructurings.

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Amount, before troubled debt restructuring, of financing receivable to be modified.

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Amount of financing receivable modified as troubled debt restructuring.

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Number of financing receivable contracts modified as troubled debt restructuring within previous 12 months, with subsequent payment default.

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Amount of financing receivable on nonaccrual status with no allowance for credit loss.

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Amount of discount (premium) attributable to other factors on financing receivable purchased with credit deterioration.

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Reflects the amount of the write-down related to a troubled debt restructuring.

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- Definition

Recorded investment of consumer mortgage loan receivables secured by residential real estate properties for which formal foreclosure proceedings are in process.

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Amount, before allowance for credit loss, of financing receivable.

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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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Amount of expense (reversal of expense) for expected credit loss for off-balance sheet credit exposure. Excludes off-balance sheet credit exposure accounted for as insurance and instrument accounted for under derivatives and hedging.

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- Definition

Carrying amount as of the balance sheet date of land and buildings obtained through foreclosure proceedings or defeasance in full or partial satisfaction of a debt arrangement.

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Loans and Allowance for Credit Losses - Textual (Details)	3 Months Ended			9 Months Ended		12 Months Ended
	Sep. 30, 2020 USD ($) loan	Jun. 30, 2020 USD ($)	Sep. 30, 2019 USD ($) loan	Sep. 30, 2020 USD ($) loan	Sep. 30, 2019 USD ($) loan	Dec. 31, 2019 USD ($)
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans	$ 14,017,442,000			$ 14,017,442,000		$ 14,425,704,000
Premiums and discounts associated with acquired loans				69,900,000		91,600,000
Financing receivable, accrued interest excluded from amortized costs	65,000,000.0			65,000,000.0		48,900,000
Nonaccrual loans with no allowance for credit loss	$ 17,800,000			$ 17,800,000
Number of loans \| loan	5		1	5	1
Balance prior to TDR	$ 1,948,000		$ 330,000	$ 1,948,000	$ 330,000
Allowance for credit losses on loans	248,251,000			248,251,000		68,244,000
Foreclosed assets and other real estate owned	12,590,000			12,590,000		19,121,000
Financing receivable, collateral dependent, amount	71,727,000			71,727,000
Unfunded commitments, allowance for credit loss	24,400,000			24,400,000		8,400,000
Off-balance sheet, credit loss, liability, credit loss expense (reversal)				$ (8,000,000.0)
Extended Maturity and Payment Deferral \| COVID-19 Pandemic
Accounts, Notes, Loans and Financing Receivable [Line Items]
Number of loans \| loan				3,956
Troubled debt, balance	3,210,944,000			$ 3,210,944,000
Deferred interest on troubled debt	27,600,000			$ 27,600,000
Number of trouble debt, previously modified, recovered \| loan				2,900
Troubled debt, previously modified, recovered	1,900,000,000			$ 1,900,000,000
Residential Real Estate
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans in process of foreclosure, amount	6,876,000			6,876,000		5,789,000
Energy
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing receivable, collateral dependent, amount	19,100,000			19,100,000
OREO Received in Full or Partial Satisfaction of Loans \| Residential Real Estate
Accounts, Notes, Loans and Financing Receivable [Line Items]
Foreclosed assets and other real estate owned	3,184,000			3,184,000		4,458,000
Real Estate
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans	9,983,253,000			9,983,253,000		11,021,940,000
Real Estate \| OREO Received in Full or Partial Satisfaction of Loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Balance prior to TDR	0		$ 0	0	$ 0
Single family residential \| Real Estate
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans	$ 1,997,070,000			$ 1,997,070,000		2,414,753,000
Number of loans \| loan	5		1	5	1
Balance prior to TDR	$ 1,948,000		$ 330,000	$ 1,948,000	$ 330,000
Allowance for credit losses on loans	16,600			16,600
Financing receivable, collateral dependent, amount	6,722,000			6,722,000
Single family residential \| Real Estate \| Energy
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing receivable, collateral dependent, amount	0			$ 0
Commercial real estate \| Real Estate
Accounts, Notes, Loans and Financing Receivable [Line Items]
Number of loans with subsequent default \| loan				1	4
Write-down of impaired loans					$ 552,000
Other commercial \| Real Estate
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total loans	6,132,823,000			$ 6,132,823,000		$ 6,358,514,000
Financing receivable, collateral dependent, amount	40,358,000			40,358,000
Other commercial \| Real Estate \| Energy
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing receivable, collateral dependent, amount	$ 0			$ 0
Charge-offs		$ 32,600,000
Other commercial \| Real Estate \| Energy \| Financial Asset, Other than Financial Asset Acquired with Credit Deterioration \| Moody's, S-2 Rating
Accounts, Notes, Loans and Financing Receivable [Line Items]
Baseline economic forecast percentage				18.00%
Other commercial \| Real Estate \| Energy \| Financial Asset, Other than Financial Asset Acquired with Credit Deterioration \| Moody's, S-3 Rating
Accounts, Notes, Loans and Financing Receivable [Line Items]
Baseline economic forecast percentage				16.00%
Other commercial \| Real Estate \| Energy \| Financial Asset, Other than Financial Asset Acquired with Credit Deterioration \| Internal Investment Grade
Accounts, Notes, Loans and Financing Receivable [Line Items]
Baseline economic forecast percentage				66.00%