(Leases Balance Sheet and Supplemental Information) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Leases [Abstract]
Operating lease right-of-use assets (Other assets on Consolidated Balance Sheets)	$ 18,619	$ 15,410
Operating lease liabilities (Accrued expenses and other liabilities on Consolidated Balance Sheets)	19,244	15,851
Right-of-use assets obtained in exchange for new operating lease liabilities	$ 7,264	$ 651
Weighted average remaining lease term	4 years 4 months 9 days	2 years 9 months
Weighted average discount rate	3.72%	4.74%
Operating Lease, Right-of-Use Asset, Statement of Financial Position [Extensible List]	us-gaap:OtherAssets	us-gaap:OtherAssets
Operating Lease, Liability, Current, Statement of Financial Position [Extensible List]	ufcs:AccruedExpensesAndOtherLiabilities	ufcs:AccruedExpensesAndOtherLiabilities