Consolidated Statements of Cash Flows (USD $) In Thousands, unless otherwise specified	6 Months Ended
	Jun. 30, 2014	Jun. 30, 2013
Operating activities
Net earnings	$ 205,047	$ 194,012
Adjustments to reconcile net earnings to net cash provided by operating activities:
Change in premium, claims and other receivables	(109,043)	(99,897)
Change in reinsurance recoverables	96,770	(17,018)
Change in ceded unearned premium	(35,485)	(35,032)
Change in loss and loss adjustment expense payable	(57,118)	52,026
Change in unearned premium	138,248	119,759
Change in reinsurance, premium and claims payable	55,764	43,237
Change in accounts payable and accrued liabilities	(69,414)	(119,103)
Stock-based compensation expense	10,303	6,955
Depreciation and amortization expense	8,289	9,093
Gain on investments	(25,151)	(13,193)
Other, net	(22,924)	(38,849)
Cash provided by operating activities	195,286	101,990
Investing activities
Sales of available for sale fixed maturity securities	286,843	171,801
Sales of equity securities	170,182	44,308
Sales of other investments	0	23,719
Maturity or call of available for sale fixed maturity securities	269,468	375,924
Cost of available for sale fixed maturity securities acquired	(675,945)	(756,782)
Cost of equity securities acquired	(78,817)	(114,685)
Change in short-term investments	(168,241)	145,977
Payments for purchase of businesses	(2,579)	(8,214)
Proceeds from sale of subsidiaries	12,942	507
Other, net	(3,902)	(2,698)
Cash provided (used) by investing activities	(190,049)	(120,143)
Financing activities
Advances on line of credit	140,000	70,000
Payments on line of credit	(60,000)	(15,000)
Sale of common stock	11,709	7,408
Purchase of common stock	(41,542)	(46,586)
Dividends paid	(45,076)	(33,250)
Other, net	2,278	3,544
Cash provided (used) by financing activities	7,369	(13,884)
Net increase (decrease) in cash	12,606	(32,037)
Cash at beginning of year	58,301	71,390
Cash at end of period	$ 70,907	$ 39,353