Consolidated Statements of Stockholders' Equity (USD $) In Thousands, unless otherwise specified		Total	Common Stock [Member]	Additional Paid-in Capital [Member]	Retained Earnings [Member]	Accumulated Other Comprehensive Income, Net of Tax [Member]	Comprehensive income (loss) [Member]
Balance at Dec. 31, 2008		$ 641,741	$ 26	$ 227,232	$ 410,634	$ 3,849
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss)		(10,441)			(10,441)		(10,441)
Summary of changes
Compensation expense and related tax benefit for stock-based award grants				2,107
Shares repurchased			0	(1,545)
Shares issued for stock-based awards			0	26
Dividends on common stock ($0.60 per share in 2011, 2010 and 2009)					(15,951)
Change in net unrealized appreciation	[1]					56,948	56,948
Change in underfunded status of employee benefit plans	[2]					(150)	(150)
All other changes in stockholders' equity accounts		41,435
Comprehensive Income (Loss) for the year							46,357
Balance at Dec. 31, 2009		672,735	26	227,820	384,242	60,647
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss)		47,513			47,513		47,513
Summary of changes
Compensation expense and related tax benefit for stock-based award grants				1,801
Shares repurchased			0	(6,280)
Shares issued for stock-based awards			0	98
Dividends on common stock ($0.60 per share in 2011, 2010 and 2009)					(15,774)
Change in net unrealized appreciation	[1]					20,158	20,158
Change in underfunded status of employee benefit plans	[2]					(3,827)	(3,827)
All other changes in stockholders' equity accounts		(3,824)
Comprehensive Income (Loss) for the year							63,844
Balance at Dec. 31, 2010		716,424	26	223,439	415,981	76,978
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss)		11			11		11
Summary of changes
Compensation expense and related tax benefit for stock-based award grants				1,830
Shares repurchased			(1)	(12,432)
Shares issued for stock-based awards			0	208
Dividends on common stock ($0.60 per share in 2011, 2010 and 2009)					(15,507)
Change in net unrealized appreciation	[1]					21,727	21,727
Change in underfunded status of employee benefit plans	[2]					(16,119)	(16,119)
All other changes in stockholders' equity accounts		(20,294)
Comprehensive Income (Loss) for the year							5,619
Balance at Dec. 31, 2011		$ 696,141	$ 25	$ 213,045	$ 400,485	$ 82,586

[1] The change in net unrealized appreciation is net of reclassification adjustments and income taxes.

[2] The recognition of the underfunded status of employee benefit plans is net of income taxes.