Other Operating Expenses (Details) - USD ($)	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Other Operating Expenses [Abstract]
Amortization of gross deferred policy acquisition costs	$ 50,270,000	$ 48,872,000	$ 47,414,000
Other underwriting expenses	42,638,000	37,830,000	35,281,000
Expense allowances from reinsurers	(28,956,000)	(23,797,000)	(20,822,000)
Total underwriting expenses	63,952,000	62,905,000	61,873,000
Operating expenses of non-insurance companies	26,621,000	25,143,000	23,488,000
Total other operating expenses	90,573,000	$ 88,048,000	$ 85,361,000
Director [Member]
Consulting Contract [Abstract]
Annual consulting contract fee	$ 300