Earnings per Share - Schedule of Earnings per Share (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Numerator
Net income attributable to UIHC common stockholders	$ (11,708)	$ (28,012)	$ 11,361	$ (16,856)
Denominator
Weighted-average shares outstanding	42,677,893	42,524,400	42,636,515	35,341,994
Effect of dilutive securities	0	216,604	154,693	221,038
Weighted-average diluted shares	42,677,893	42,741,004	42,791,208	35,563,032
Basic earnings per share	$ (0.27)	$ (0.66)	$ 0.27	$ (0.48)
Diluted earnings per share	$ (0.27)	$ (0.66)	$ 0.27	$ (0.47)