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Recent Accounting Pronouncements (Details) - USD ($) $ in Thousands		Dec. 31, 2020	Dec. 31, 2019
Recent Accounting Pronouncements [Abstract]
Retained earnings		$ 749,056	$ 696,214
Allowance for credit losses	[1]	110,000
COVID-19 [Member]
Recent Accounting Pronouncements [Abstract]
Loans in modification programs related to COVID-19		110,800
ASU 2016-13 [Member]
Recent Accounting Pronouncements [Abstract]
Allowance for credit losses		$ 110,000	75,999
ASU 2016-13 [Member] | Cumulative Effect Adjustment for ASU Implementation [Member]
Recent Accounting Pronouncements [Abstract]
Retained earnings			(4,300)
Allowance for credit losses			3,000
Allowance for credit losses on off-balance sheet credit exposure			2,800
Deferred tax asset			$ (1,500)
[1] Beginning January 1, 2020, calculation is based on current expected loss methodology. Prior to January 1, 2020, calculation was based on incurred loss methodology.

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Amount, after allocation of valuation allowances and deferred tax liability, of deferred tax asset attributable to deductible differences and carryforwards, with jurisdictional netting.

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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 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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