Statutory (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Statutory [Abstract]
Net income of the insurance subsidiaries in accordance with statutory accounting practices	$ 22,000	$ 31,647	$ 25,627
Consolidated statutory capital and surplus for subsidiaries	421,663	$ 399,314
Amount of statutory surplus transferred by dividend or loan to the parent company	59,106
Minimum statutory surplus necessary for the insurance subsidiaries to satisfy statutory risk based capital requirements	104,913
Consolidated statutory capital and surplus exceeded requirement	$ 316,750