Consolidated Statements of Cash Flows - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Cash flows from operating activities:
Net earnings	$ 137,544	$ 135,445	$ 126,255
Adjustments to reconcile net earnings to net cash provided by operating activities
Net realized gains	(39,829)	(32,182)	(22,036)
Depreciation	5,406	4,557	3,765
Other items, net	15,006	10,818	13,104
Change in:
Accrued investment income	(249)	1,081	(1,307)
Premiums and reinsurance balances receivable (net of direct write-offs and commutations)	10,911	(2,064)	(13,154)
Reinsurance balances payable	(457)	(9,321)	3,375
Funds held	2,773	(10,175)	5,023
Ceded unearned premium	1,128	6,446	12,785
Reinsurance balances recoverable on unpaid losses	37,262	19,818	4,960
Deferred policy acquisition costs	(4,706)	(3,615)	(9,164)
Accrued expenses	(7,406)	3,552	9,663
Unpaid losses and settlement expenses	(17,255)	(8,393)	(29,050)
Unearned premiums	20,682	9,331	22,735
Income taxes
Current	7,069	(155)	5,966
Deferred	7,034	5,446	6,065
Stock option excess tax benefit	(11,413)	(1,766)	(6,310)
Changes in investment in unconsolidated investees:
Undistributed earnings	(10,914)	(12,338)	(10,915)
Dividends received		6,600	13,200
Net proceeds from trading portfolio activity			6
Net cash provided by operating activities	152,586	123,085	134,966
Purchase of:
Fixed income, available-for-sale	(665,422)	(470,210)	(545,899)
Equity securities, available-for-sale	(39,905)	(18,088)	(31,010)
Property and equipment	(10,035)	(7,121)	(17,531)
Investment in equity method investee	(1,711)	(5,301)
Other	(4,642)	(5,534)
Proceeds from sale of:
Fixed income, held-to-maturity		654
Fixed income, available-for-sale	436,680	342,308	173,694
Equity securities, available-for-sale	53,110	72,869	73,982
Short-term investments, net	6,637	11,401	7,230
Property and equipment	76	276	1,492
Subsidiary (RLI Indemnity Company)	7,500
Other	135		400
Proceeds from call or maturity of:
Fixed income, held-to-maturity			11,090
Fixed income, available-for-sale	156,980	101,517	224,620
Net cash provided by (used in) investing activities	(60,597)	22,771	(101,932)
Cash Flows from financing activities
Stock option excess tax benefit	11,413	1,766	6,310
Proceeds from stock option exercises	(3,364)	3,386	318
Proceeds from issuance of senior notes			149,571
Payment on senior notes			(99,504)
Debt issue costs paid			(1,437)
Cash dividends paid	(119,577)	(159,857)	(93,137)
Net cash used in financing activities	(111,528)	(154,705)	(37,879)
Net decrease in cash	(19,539)	(8,849)	(4,845)
Cash at the beginning of year	30,620	39,469	44,314
Cash at end of year	$ 11,081	$ 30,620	$ 39,469