Consolidated Statements of Cash Flows - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Operating activities
Net income	$ 65,756	$ 86,602	$ 92,690
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation	1,017	1,012	942
Net amortization of investments	8,868	8,177	8,659
Change in investment related allowance for credit losses	(79)	(27)
Deferred income taxes	1,270	1,657	872
Net realized (gains) losses on investments	(1,695)	(1,132)	80
Net unrealized gains on equity securities	(12,315)	(4,204)	(4,758)
Net realized (gains) losses on disposal of assets	(21)	58	3
Share-based compensation	2,320	3,296	2,351
Changes in operating assets and liabilities:
Premiums receivable, net	21,660	1,193	4,525
Accrued interest receivable	1,194	456	467
Deferred policy acquisition costs	751	1,238	686
Amounts held by others	71	7,856
Other assets	(1,016)	(1,230)	710
Reserves for loss and loss adjustment expenses	(15,283)	(12,326)	(25,522)
Unearned premiums	(8,168)	(11,613)	(8,423)
Reinsurance balances	(14,648)	(10,333)	16,093
Amounts held for others and policyholder deposits	(2,628)	2,271	(5,528)
Federal income taxes payable	(6,831)	(2,803)	(192)
Accounts payable and other liabilities	(2,244)	(6,750)	(4,831)
Net cash provided by operating activities	37,979	63,398	78,824
Investing activities
Purchases of investments held-to-maturity	(43,307)	(96,452)	(152,133)
Purchases of investments available-for-sale	(51,617)	(73,923)	(63,513)
Purchases of equity securities	(8,388)	(11,330)	(4,495)
Purchases of short-term investments	(167,870)	(139,242)	(125,763)
Proceeds from maturities of investments held-to-maturity	74,253	104,564	159,702
Proceeds from sales and maturities of investments available-for-sale	114,974	110,700	114,869
Proceeds from sales and maturities of short-term investments	154,187	149,975	84,039
Purchases of property and equipment	(1,296)	(921)	(1,018)
Proceeds from sales of property and equipment	23
Net cash provided by investing activities	70,959	43,371	11,688
Financing activities
Proceeds from stock option exercises			20
Finance lease purchases	(44)	(50)	(47)
Dividends to shareholders	(99,929)	(88,775)	(87,016)
Net cash used in financing activities	(99,973)	(88,825)	(87,043)
Change in cash and cash equivalents	8,965	17,944	3,469
Cash and cash equivalents at beginning of year	61,757	43,813	40,344
Cash and cash equivalents at end of year	70,722	61,757	43,813
Supplemental disclosure of cash flow information
Income taxes paid	$ 18,198	$ 20,562	$ 20,850