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Statements of Cash Flows (Cash Flow Supplemental Disclosures) (Details) - USD ($) $ in Thousands		3 Months Ended
		Mar. 31, 2022	Mar. 31, 2021
Interest		$ 8,523	$ 8,722
Federal income tax		(800)	0
Operating cash flows from operating leases		2,058	2,226
Operating cash flows from financing leases		11	2
Financing cash flows from finance leases		612	115
Assets acquired under finance lease arrangements		38	183
Assets acquired under operating lease arrangements		5,760	16
Non-cash purchase of property and equipment		0	3
Available-for-sale Securities
Corporate actions related to securities	[1]	$ 1,244	$ 26,085
[1] Examples of corporate actions include like-kind exchanges, non-cash acquisitions, and stock splits.

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Amount of cash paid for interest, including, but not limited to, capitalized interest and payment to settle zero-coupon bond attributable to accreted interest of debt discount and debt instrument with insignificant coupon interest rate in relation to effective interest rate of borrowing attributable to accreted interest of debt discount; classified as operating and investing activities.

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