CONSOLIDATED STATEMENTS OF INCOME (Unaudited) (Parenthetical) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
REVENUES
Premiums earned, affiliated	$ 154,246	$ 143,611
Other income, affiliated	1,581	1,009
LOSSES AND EXPENSES
Losses and settlement expenses, affiliated	110,570	94,771
Amortization of deferred policy acquisition costs, affiliated	26,917	26,595
Other underwriting expenses, affiliated	22,920	20,693
Other expense, affiliated	$ 498	$ 467