Schedule II. Condensed Financial Statements of Parent Company (Condensed Balance Sheets) (Details) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Assets
Available-for-sale, at fair value (amortized cost $150 in 2019 and $150 in 2018)	$ 1,719,607	$ 1,749,488
Cash and cash equivalents	120,722	64,454
Federal income tax receivable	19,190	15,035
Accrued investment income	15,182	15,774
Total assets	3,013,472	2,816,698
Liabilities and stockholders' equity
Liabilities	2,103,000	1,928,323
Stockholders' equity
Common stock, $0.001 par value, authorized 75,000,000 shares; 25,015,963 and 25,097,408 issued and outstanding in 2019 and 2018, respectively	25	25
Additional paid-in capital	200,179	203,350
Retained earnings	697,116	715,472
Accumulated other comprehensive income, net of tax	13,152	(30,472)
Total stockholders' equity	910,472	888,375	$ 973,373	$ 941,884
Total liabilities and stockholders' equity	3,013,472	2,816,698
United Fire Group, Inc.
Assets
Available-for-sale, at fair value (amortized cost $150 in 2019 and $150 in 2018)	150	150
Investment in subsidiary	880,485	877,893
Cash and cash equivalents	29,878	9,186
Federal income tax receivable	0	1,165
Accrued investment income	3	1
Total assets	910,516	888,395
Liabilities and stockholders' equity
Liabilities	44	20
Stockholders' equity
Common stock, $0.001 par value, authorized 75,000,000 shares; 25,015,963 and 25,097,408 issued and outstanding in 2019 and 2018, respectively	25	25
Additional paid-in capital	200,179	203,350
Retained earnings	697,116	715,472
Accumulated other comprehensive income, net of tax	13,152	(30,472)
Total stockholders' equity	910,472	888,375
Total liabilities and stockholders' equity	$ 910,516	$ 888,395