Summary of Significant Accounting Policies - Narrative (Details)			12 Months Ended
	Sep. 30, 2020 USD ($)	Mar. 27, 2020 USD ($)	Dec. 31, 2021 USD ($) plan state segment variable_interest_entity	Dec. 31, 2020 USD ($)	Dec. 31, 2019 USD ($)	Dec. 15, 2020 USD ($)
New Accounting Pronouncements or Change in Accounting Principle [Line Items
Number of states in which we are licensed as insurer | state			50
Percentage of the gains and profits from the Lloyds plan available to United Fire & Indemnity Company			100.00%
Number of reportable segments | segment			1
Cash on deposit			$ 21,333,000
Securities on deposit as required by law			26,196,000	$ 21,628,000
Depreciation expense			5,861,000	5,947,000	$ 10,482,000
Goodwill impairment	$ 15,091,000		0	15,091,000	0
Interest Expense			3,187,000	0	0
Income tax benefit, CARES Act		$ 18,562,000
Unrecognized tax benefit			0	0	0
Payment for income taxes			5,360,000	138,000	1,575,000
Federal tax refund received			$ 28,083,000	0	5,401,000
Number of VIEs | variable_interest_entity			1
Interest payment			$ 0	0	0
Assets			$ 3,012,721,000	3,069,678,000
Number of equity compensation plans | plan			2
Credit loss allowance for reinsurance receivables			$ 102,000	190,000
Variable Interest Entity, Not Primary Beneficiary
New Accounting Pronouncements or Change in Accounting Principle [Line Items
Assets			2,900,000
Surplus Notes
New Accounting Pronouncements or Change in Accounting Principle [Line Items
Principal amount						$ 50,000,000
Debt issuance costs						24,000
Interest Expense			$ 3,187,000
Surplus Notes | Federated Mutual
New Accounting Pronouncements or Change in Accounting Principle [Line Items
Principal amount						35,000,000
Surplus Notes | Federated Life
New Accounting Pronouncements or Change in Accounting Principle [Line Items
Principal amount						$ 15,000,000
Minimum
New Accounting Pronouncements or Change in Accounting Principle [Line Items
Useful life			2 years
Maximum
New Accounting Pronouncements or Change in Accounting Principle [Line Items
Useful life			15 years
Property and casualty business
New Accounting Pronouncements or Change in Accounting Principle [Line Items
Amortization expense			$ 709,000	$ 709,000	$ 709,000