Derivative Financial Instruments (Details) - USD ($) $ in Thousands	3 Months Ended
Mar. 31, 2021	Mar. 31, 2020	Dec. 31, 2020
Junior subordinated debentures	$ 44,712		$ 43,136
Notional amount	1,574,078		1,481,109
Short-term Debt, Total	1,021,500		1,021,500
Amount reclassified from accumulated other comprehensive loss to interest expense	2,600	$ 200
Amount to be reclassified from the accumulated comprehensive income (loss) into earnings	10,500
Derivative instruments	(29,728)		(59,668)
Customer [Member]
Derivative instruments	110,500		62,800
Bank [Member]
Derivative instruments	110,500		62,800
Customer and Bank [Member]
Derivative instruments	221,100		125,600
Not Designated as Hedging Instrument [Member]
Notional amount	239,100		143,600
Designated as Hedging Instrument [Member]
Notional amount	313,500		316,100
Designated as Hedging Instrument [Member] \| Cash Flow Hedging [Member]
Notional amount	1,021,500		1,021,500
Interest Rate Swap [Member]
Notional amount	313,500		316,100
Interest Rate Swap [Member] \| Not Designated as Hedging Instrument [Member]
Notional amount	128,538		80,779
Derivative instruments	(6,707)		(6,998)
Interest Rate Swap [Member] \| Designated as Hedging Instrument [Member] \| Cash Flow Hedging [Member]
Notional amount	666,500		1,021,500
Derivative instruments	(19,465)		(25,300)
Floating Rate Junior Subordinated Debentures [Member]
Amount of hedged item	18,000		18,000
Junior subordinated debentures	$ 61,900		$ 61,900

Amount of hedged item in hedging relationship. Excludes hedged asset or liability.

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Nominal or face amount used to calculate payments on the derivative asset.

+ References

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- Definition

The estimated value of gains (losses), net anticipated to be transferred in the future from accumulated other comprehensive income into earnings.

+ References

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- Definition

Fair value as of the balance sheet date of interest rate derivative assets, net of interest rate derivative liabilities, which includes all such derivative instruments in hedging and nonhedging relationships that are recognized on the balance sheet.

+ References

No definition available.

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Including the current and noncurrent portions, carrying value as of the balance sheet date of long-term debt (with maturities initially due after one year or beyond the operating cycle if longer) identified as Junior Subordinated Notes, which have a lower priority than senior instruments.

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Amount before tax of reclassification adjustments of other comprehensive income (loss).

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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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