Consolidated Statements of Changes in Stockholders' Equity (USD $) In Thousands, unless otherwise specified	Total	Preferred Stock	Common Stock	Contributed Capital	Accumulated Other Comprehensive Income	Treasury Stock	Retained Earnings
Beginning Balance at Dec. 31, 2008	$ 2,646,689	$ 299,429	$ 8,349	$ 742,863	$ 87,249	$ (24,290)	$ 1,533,089
Net earnings	270,999						270,999
Other comprehensive loss, net of tax:
Retirement plans	(1,011)				(1,011)
Change in unrealized appreciation of investments, net	7,807				7,807
Comprehensive income	277,795				6,796		270,999
Dividends paid	(6,683)		72	11,246		26,629	(44,630)
Stock based compensation	1,186			1,186
Treasury stock purchase	(75,856)					(75,856)
Preferred stock repurchase	(117,218)	(117,218)
Conversion of preferred stock		(182,211)	698	181,513
Other, net	(8,392)		(1)	(15,583)		7,192
Ending Balance at Dec. 31, 2009	2,717,521		9,118	921,225	94,045	(66,325)	1,759,458
Net earnings	198,502						198,502
Other comprehensive loss, net of tax:
Retirement plans	7,287				7,287
Change in unrealized appreciation of investments, net	68,930				68,930
Comprehensive income	274,719				76,217		198,502
Dividends paid	(548)			7,051		45,461	(53,060)
Stock based compensation	340			340
Treasury stock purchase	(83,135)					(83,135)
Other, net	(29)			200		4,313	(4,542)
Ending Balance at Dec. 31, 2010	2,908,868		9,118	928,816	170,262	(99,686)	1,900,358
Net earnings	143,251						143,251
Other comprehensive loss, net of tax:
Retirement plans	(3,407)				(3,407)
Change in unrealized appreciation of investments, net	(11,324)				(11,324)
Comprehensive income	128,520				(14,731)		143,251
Dividends paid	(547)			8,408		49,405	(58,360)
Stock based compensation	101			101
Treasury stock purchase	(120,325)					(120,325)
Other, net	9,060			712	1	3,287	5,060
Ending Balance at Dec. 31, 2011	$ 2,925,677		$ 9,118	$ 938,037	$ 155,532	$ (167,319)	$ 1,990,309