Consolidated Statements Of Cash Flows (Unaudited) - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016
CASH FLOWS FROM OPERATING ACTIVITIES
Net income	$ 78,613	$ 72,196
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	27,525	25,918
Net realized investment gains	(45,616)	(70,438)
Increase in premiums receivable	(9,929)	(23,456)
Changes in current and deferred income taxes	13,674	17,871
Decrease (increase) in deferred policy acquisition costs	1,756	(2,231)
Increase in loss and loss adjustment expense reserves	36,715	64,104
Increase in unearned premiums	19,157	30,824
Increase (decrease) in accounts payable and accrued expenses	9,068	(6,166)
Share-based compensation	56	71
Other, net	43,726	(2,901)
Net cash provided by operating activities	174,745	105,792
CASH FLOWS FROM INVESTING ACTIVITIES
Fixed maturities available-for-sale in nature: Purchases	(440,294)	(491,231)
Fixed maturities available-for-sale in nature: Sales	65,211	172,490
Fixed maturities available-for-sale in nature: Calls or maturities	258,782	288,257
Equity securities available for sale in nature:
Equity securities available for sale in nature: Purchases	(368,896)	(337,598)
Equity securities available for sale in nature: Sales	303,574	310,369
Equity securities available for sale in nature: Calls	7,100	0
Changes in securities payable and receivable	(29,674)	(2,388)
Net decrease in short-term investments and purchased options	97,790	1,677
Purchase of fixed assets	(10,557)	(8,935)
Sale of fixed assets	0	2
Other, net	3	2,343
Net cash used in investing activities	(116,961)	(65,014)
CASH FLOWS FROM FINANCING ACTIVITIES
Dividends paid to shareholders	(68,859)	(68,515)
Employee taxes paid for withheld shares related to share-based compensation	0	(3,203)
Proceeds from stock options exercised	1,171	0
Net proceeds from issuance of senior notes	371,011	0
Payoff of principal on loan and credit facilities	(320,000)	0
Net cash used in financing activities	(16,677)	(71,718)
Net increase (decrease) in cash	41,107	(30,940)
Cash:
Beginning of the year	220,318	264,221
End of period	261,425	233,281
SUPPLEMENTAL CASH FLOW DISCLOSURE
Interest paid	1,292	1,820
Income taxes paid	$ 7,063	$ 273