Schedule II. Condensed Financial Statements of Parent Company (Condensed Balance Sheet) (Details) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012		Dec. 31, 2011		Dec. 31, 2010
Condensed Balance Sheet Statements, Captions [Line Items]
Fixed maturities, held-to-maturity, at amortized cost (fair value $200 in 2013 and $200 in 2012)	$ 656	$ 1,655
Cash and cash equivalents	92,193	107,466		144,527		180,057
Federal income tax receivable	1,786	16,536
Investment income receivable	27,923	30,375
TOTAL ASSETS	3,720,672	3,694,653		3,618,924
Liabilities	2,937,839	2,965,476
Common stock, $0.001 par value, authorized 75,000,000 shares; 25,360,893 and 25,277,463 issued and outstanding in 2013 and 2012, respectively	25	25
Additional paid-in capital	211,574	208,536
Retained earnings	484,084	425,428
Accumulated other comprehensive income, net of tax	87,150	95,188		82,586		76,978
TOTAL STOCKHOLDERS' EQUITY	782,833	729,177		696,141		716,424
TOTAL LIABILITIES AND STOCKHOLDERS' EQUITY	3,720,672	3,694,653
United Fire Group, Inc. [Member]
Condensed Balance Sheet Statements, Captions [Line Items]
Fixed maturities, held-to-maturity, at amortized cost (fair value $200 in 2013 and $200 in 2012)	200	200
Investment in subsidiary	778,843	723,705
Cash and cash equivalents	3,253	5,140	[1]	0	[1]
Federal income tax receivable	537	131
Investment income receivable	1	1
TOTAL ASSETS	782,834	729,177
Liabilities	1	0
Common stock, $0.001 par value, authorized 75,000,000 shares; 25,360,893 and 25,277,463 issued and outstanding in 2013 and 2012, respectively	25	25
Additional paid-in capital	211,574	208,536
Retained earnings	484,084	425,428
Accumulated other comprehensive income, net of tax	87,150	95,188
TOTAL STOCKHOLDERS' EQUITY	782,833	729,177
TOTAL LIABILITIES AND STOCKHOLDERS' EQUITY	$ 782,834	$ 729,177

[1] The Condensed Statement of Cash Flows includes the full year 2012 results. The results of January 2012 are immaterial to the full year 2012 results.