Stockholders' Equity Dividends (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended												12 Months Ended
	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Dividend paid to parent [Line Items]
Common Stock, Dividends, Per Share, Declared	$ 0.06	$ 0.06	$ 0.06	$ 0.06	$ 0.06	$ 0.06	$ 0.06	$ 0.06	$ 0.06	$ 0.06	$ 0.06	$ 0.05
Dividends, Common Stock, Cash	$ 2,569	$ 2,569	$ 2,565	$ 2,565	$ 2,565	$ 2,564	$ 2,561	$ 1,301	$ 1,299	$ 1,299	$ 1,300	$ 1,076	$ 10,268	$ 8,991	$ 4,974
American Coastal Insurance Company
Dividend paid to parent [Line Items]
Statutory Accounting Practices, Dividends Paid with Approval of Regulatory Agency													50,000
Interboro Insurance Company
Dividend paid to parent [Line Items]
Statutory Accounting Practices, Dividends Paid with Approval of Regulatory Agency													$ 1,764