Face (par) amount of debt instrument at time of issuance.

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Contractual interest rate for funds borrowed, under the debt agreement.

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Amount, after accumulated amortization, of debt discount.

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Amount, after accumulated amortization, of debt issuance costs. Includes, but is not limited to, legal, accounting, underwriting, printing, and registration costs.

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The percentage points added to the reference rate to compute the variable rate on the interest rate derivative.

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Amount of cumulative increase (decrease) in fair value of hedged liability in fair value hedge, attributable to hedged risk.

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Amount, after unamortized (discount) premium and debt issuance costs, of long-term debt. Includes, but not limited to, notes payable, bonds payable, debentures, mortgage loans and commercial paper. Excludes capital lease obligations.

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The interest rate applicable to the portion of the carrying amount of long-term borrowings outstanding as of the balance sheet date, including current maturities, which accrues interest at a rate subject to change from time to time.

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Borrowings (Long-Term Debt) (Details) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019	Sep. 30, 2019
Debt Instrument [Line Items]
Notes and subordinated debt	$ 571,484	$ 544,806
Debt issuance cost on senior fixed-rate notes	(2,628)	(3,030)
Long-term debt	$ 567,663	$ 540,364
Long term debt, variable interest rate, percentage	3.18%	4.85%
Hedged Liability, Fair Value Hedge, Cumulative Increase (Decrease)			$ 17,486
London Interbank Offered Rate (LIBOR) [Member]
Debt Instrument [Line Items]
Interest rate spread of LIBOR plus (as a percent)	2.95%
Junior Subordinated Debt [Member]
Debt Instrument [Line Items]
Notes and subordinated debt	$ 77,320	$ 77,320
Long-term Debt [Member]
Debt Instrument [Line Items]
Discount on senior fixed-rate notes	(1,193)	(1,412)
Hedged Liability, Fair Value Hedge, Cumulative Increase (Decrease)	44,200
Debt Instrument, Redemption, Period One [Member] \| Senior Notes [Member]
Debt Instrument [Line Items]
Notes and subordinated debt	$ 150,000	150,000
Debt instrument, stated interest rate, percentage	4.375%
Debt Instrument, Redemption, Period Two \| Senior Notes [Member]
Debt Instrument [Line Items]
Notes and subordinated debt	$ 344,164	$ 317,486
Debt instrument, stated interest rate, percentage	4.10%