Schedule II. Condensed Financial Statements of Parent Company (Condensed Balance Sheet) (Details) - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Assets
Fixed maturities, held-to-maturity, at amortized cost (fair value $150 in 2015 and $200 in 2014)	$ 672	$ 397
Cash and cash equivalents	106,449	90,574	$ 92,193	$ 107,466
Accrued investment income	25,136	25,989
Total assets	3,890,376	3,856,689	3,720,672
Liabilities and stockholders' equity
Liabilities	3,011,479	3,039,274
Stockholders' equity
Common stock, $0.001 par value, authorized 75,000,000 shares; 25,151,428 and 25,019,415 issued and outstanding in 2015 and 2014, respectively	25	25
Additional paid-in capital	207,426	202,676
Retained earnings	591,009	523,541
Accumulated other comprehensive income, net of tax	80,437	91,173	87,150	95,188
Total stockholders' equity	878,897	817,415	782,833	729,177
Total liabilities and stockholders' equity	3,890,376	3,856,689
United Fire Group, Inc. [Member]
Assets
Fixed maturities, held-to-maturity, at amortized cost (fair value $150 in 2015 and $200 in 2014)	150	200
Investment in subsidiary	871,590	814,569
Cash and cash equivalents	6,565	2,263	$ 3,253	$ 5,140
Federal income tax receivable	591	383
Accrued investment income	1	1
Total assets	878,897	817,416
Liabilities and stockholders' equity
Liabilities	0	1
Stockholders' equity
Common stock, $0.001 par value, authorized 75,000,000 shares; 25,151,428 and 25,019,415 issued and outstanding in 2015 and 2014, respectively	25	25
Additional paid-in capital	207,426	202,676
Retained earnings	591,009	523,541
Accumulated other comprehensive income, net of tax	80,437	91,173
Total stockholders' equity	878,897	817,415
Total liabilities and stockholders' equity	$ 878,897	$ 817,416