Schedule II. Condensed Financial Statements of Parent Company (Condensed Balance Sheet) (Details) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012		Dec. 31, 2011
Condensed Balance Sheet Statements, Captions [Line Items]
Fixed maturities, held-to-maturity, at amortized cost (fair value $200 in 2014 and $200 in 2013)	$ 397	$ 656
Cash and cash equivalents	90,574	92,193	107,466		144,527
Federal income tax receivable	0	1,786
Accrued investment income	25,989	27,923
Total assets	3,856,689	3,720,672	3,694,653
Liabilities	3,039,274	2,937,839
Common stock, $0.001 par value, authorized 75,000,000 shares; 25,019,415 and 25,360,893 issued and outstanding in 2014 and 2013, respectively	25	25
Additional paid-in capital	202,676	211,574
Retained earnings	523,541	484,084
Accumulated other comprehensive income, net of tax	91,173	87,150	95,188		82,586
Total stockholders' equity	817,415	782,833	729,177		696,141
Total liabilities and stockholders' equity	3,856,689	3,720,672
United Fire Group, Inc. [Member]
Condensed Balance Sheet Statements, Captions [Line Items]
Fixed maturities, held-to-maturity, at amortized cost (fair value $200 in 2014 and $200 in 2013)	200	200
Investment in subsidiary	814,569	778,843
Cash and cash equivalents	2,263	3,253	5,140	[1]	0	[1]
Federal income tax receivable	383	537
Accrued investment income	1	1
Total assets	817,416	782,834
Liabilities	1	1
Common stock, $0.001 par value, authorized 75,000,000 shares; 25,019,415 and 25,360,893 issued and outstanding in 2014 and 2013, respectively	25	25
Additional paid-in capital	202,676	211,574
Retained earnings	523,541	484,084
Accumulated other comprehensive income, net of tax	91,173	87,150
Total stockholders' equity	817,415	782,833
Total liabilities and stockholders' equity	$ 817,416	$ 782,834

[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.