Shareholders' Equity (Details) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2020		Dec. 31, 2019	Dec. 31, 2018
Increase (Decrease) in Common Stock Outstanding and Additional Paid-In Capital [Roll Forward]
Dividends paid to shareholders	$ 5,692		$ 5,857	$ 16,835
Cash dividends paid (in dollars per share)	$ 0.40		$ 0.40	$ 1.12
Stock repurchase program, shares authorized (in shares)	2,464,209
Repurchase of common shares	$ 1,782		$ 11,501	$ 4,596
Investments [Abstract]
Total unrealized gain before federal income tax expense (benefit)	26,259		12,491
Deferred tax benefit (liability)	(4,255)	[1]	(2,628)
Net unrealized gains on investments	22,004		9,863
Foreign exchange adjustment [Abstract]
Total unrealized losses	(310)		(625)
Deferred tax benefit	65		131
Net unrealized losses on foreign exchange adjustment	(245)		(494)
Accumulated other comprehensive income	21,759		9,369
Investments [Abstract]
Pre-tax holding gains (losses) on fixed income securities arising during period	10,501		19,182	(12,253)
Less: applicable federal income tax expense (benefit)	941	[1]	4,028	(2,573)
Net unrealized gains (losses) on investments	9,560		15,154	(9,680)
Pre-tax gains (losses) on fixed income securities included in net income (loss) during period	(3,267)	[1]	(1,161)	(3,560)
Less: applicable federal income tax expense (benefit)	(686)		(244)	(748)
Other comprehensive income (loss), reclassification adjustment for sale of securities included in net income, net of tax	(2,581)		(917)	(2,812)
Change in unrealized gains (losses) on investments	12,141		16,071	(6,868)
Valuation allowance	$ 1,264		$ 0	$ 0
Class A [Member]
Increase (Decrease) in Common Stock Outstanding and Additional Paid-In Capital [Roll Forward]
Stated value of common stock (in dollars per share)	$ 0.04
Class B [Member]
Increase (Decrease) in Common Stock Outstanding and Additional Paid-In Capital [Roll Forward]
Stated value of common stock (in dollars per share)	$ 0.04
Repurchase of common stock (in shares)	126,764
Average share price (in dollars per share)	$ 14.07

[1] Includes the $1,264 valuation allowance benefit recorded in other comprehensive income.  See Note E - Income Taxes for additional information.