Schedule IV - Reinsurance (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Consolidated earned premiums [Abstract]
Gross amount	$ 366,752	$ 372,658	$ 361,010
Ceded to other companies	407,531	423,602	413,422
Assumed from other companies	611,045	591,666	567,918
Net amount	$ 570,266	$ 540,722	$ 515,506
Percentage of amount assumed to net	107.20%	109.40%	110.20%