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Commitments, Contingencies And Guarantees (Narrative) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Notional amount of underlying swaps	$ 3,015,189	$ 4,525,856
Financial Standby Letter of Credit [Member]
Carrying value of the guarantee obligations, liability	3,300
Commitments outstanding	357,087	$ 377,338
State Tax Credits [Member]
Purchases of state tax credits	151,200
Sales of state tax credits	131,400
Outstanding purchase commitments expected to fund	141,300
Risk Participation Agreement [Member]
Carrying value of the guarantee obligations, liability	701
Notional amount of underlying swaps	$ 288,700
Risk Participation Agreement [Member] | Minimum [Member]
Risk Participation Agreements, Term	2 years
Risk Participation Agreement [Member] | Maximum [Member]
Risk Participation Agreements, Term	11 years
Office Building
Outstanding purchase commitments expected to fund	$ 106,600
Lessor, Operating Lease, Lease Not yet Commenced, Term of Contract	15 years
Anchor Tenant Percent of Building Leased	40.00%

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Purchases of state tax credits arising from third party property redevelopment, mainly to be resold to third parties.

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Sales of state tax credits arising from third party property redevelopment. These were primarily purchased by the Company with the purpose of reselling to third parties.

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Nominal or face amount used to calculate payment on derivative.

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Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 815
-SubTopic 10
-Section 50
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The current carrying amount of the liability for the freestanding or embedded guarantor's obligations under the guarantee or each group of similar guarantees.

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Maximum potential amount of future payments (undiscounted) the guarantor could be required to make under the guarantee or each group of similar guarantees before reduction for potential recoveries under recourse or collateralization provisions.

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Term of lessor's operating lease not yet commenced, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents reported fact of one year, five months, and thirteen days.

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Minimum amount to be expended to satisfy the terms of arrangements in which the entity has agreed to expend funds to procure goods or services, excluding long-term purchase commitments or unconditional purchase obligations.

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