CONSOLIDATED STATEMENTS OF INCOME (Parenthetical) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
REVENUES
Premiums earned, affiliated	$ 566,103	$ 534,105	$ 509,704
Other income, affiliated	1,214	1,784	834
LOSSES AND EXPENSES
Losses and settlement expenses, affiliated	368,722	378,263	326,130
Amortization of deferred policy acquisition costs, affiliated	101,090	97,551	93,116
Other underwriting expenses, affiliated	68,305	57,148	65,575
Other expense, affiliated	$ 1,822	$ 1,570	$ 1,356