Consolidated Statements of Comprehensive Income (Loss) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Statement of Comprehensive Income [Abstract]
Net income (loss)	$ (21,542)	$ (8,437)	$ (17)
Unrealized investment gains (losses):
Unrealized investment gains (losses) during the period	1,151	(2,139)	(274)
Income tax expense (benefit)	356	0	0
Unrealized investment gains (losses), net of tax	795	(2,139)	(274)
Less: reclassification adjustments to:
Net realized investment gains included in net income (loss)	78	(877)	702
Income tax expense	0	0	0
Total reclassifications included in net income (loss), net of tax	78	(877)	702
Other comprehensive income (loss)	717	(1,262)	(976)
Total comprehensive income (loss)	(20,825)	(9,699)	(993)
Less comprehensive income (loss) attributable to noncontrolling interest	0	0	(81)
Comprehensive income (loss) attributable to Conifer	$ (20,825)	$ (9,699)	$ (912)