Earnings per Share (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Earnings Per Share, Basic, by Common Class, Including Two Class Method [Line Items]
Net income attributable to FBL Financial Group, Inc.	$ 26,880	$ 30,017	$ 24,380	$ 25,946	$ 30,905	$ 26,659	$ 32,372	$ 23,591	$ 107,223	$ 113,527	$ 109,941
Dividends on preferred stock									150	150	150
Income available to common stockholders									$ 107,073	$ 113,377	$ 109,791
Weighted Average Number of Shares Outstanding, Basic									24,985,400	24,927,209	24,866,284
Weighted Average Number Diluted Shares Outstanding Adjustment									43,683	89,274	149,960
Weighted Average Number of Shares Outstanding, Diluted									25,029,083	25,016,483	25,016,244
Earnings per common share	$ 1.07	$ 1.20	$ 0.97	$ 1.04	$ 1.24	$ 1.07	$ 1.30	$ 0.95	$ 4.29	$ 4.55	$ 4.42
Earnings per common share - assuming dilution	$ 1.07	$ 1.20	$ 0.97	$ 1.04	$ 1.23	$ 1.06	$ 1.29	$ 0.94	$ 4.28	$ 4.53	$ 4.39