Consolidated Statement of Shareholders' Equity (USD $) In Thousands, except Share data, unless otherwise specified	Total	Class A Common Stock	Class B Common Stock	Capital in Excess of Par Value [Member]	Accumulated deficit [Member]	Accumulated other comprehensive loss [Member]	Class A Treasury Stock [Member]
Balance at Dec. 31, 2009	$ 143,820	$ 283	$ 267	$ 290,387	$ (146,605)	$ 263	$ (775)
Balance, Shares at Dec. 31, 2009		28,313,000	26,690,000				(59,000)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net loss	(9,596)				(9,596)
Other comprehensive loss	(381)					(381)
Conversion of shares	0	4	(4)
Conversion of shares, shares		372,000	(372,000)
Issuance of shares of stock in conjunction with stock option exercises	295	2		293
Issuance of shares of stock in conjunction with stock option exercise, shares		142,000
Issuance of shares of stock and restricted stock, net of cancellations and tax withholdings	(461)	(1)		(460)
Issuance of shares of stock and restricted stock, net of cancellations and tax withholdings, shares		(74,000)
Non-cash equity compensation	5,356			5,356
Balance at Dec. 31, 2010	139,033	288	263	295,576	(156,201)	(118)	(775)
Balance, shares at Dec. 31, 2010		28,753,000	26,318,000				(59,000)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net loss	(15,519)				(15,519)
Other comprehensive loss	(48)					(48)
Conversion of shares	0	3	(3)
Conversion of shares, shares		333,000	(333,000)
Issuance of shares of stock in conjunction with stock option exercises	1,712	8		1,704
Issuance of shares of stock in conjunction with stock option exercise, shares		840,000
Issuance of shares of stock and restricted stock, net of cancellations and tax withholdings	(78)	0		(78)
Issuance of shares of stock and restricted stock, net of cancellations and tax withholdings, shares		(32,000)
Issuance of shares of stock in connection with equity sale, net of expenses	34,593	110		34,483
Issuance of shares of stock in connection with equity sale, net of expenses, shares		11,000,000
Common stock dividends	(16,722)				(16,722)
Non-cash equity compensation	4,976			4,976
Balance at Dec. 31, 2011	147,947	409	260	336,661	(188,442)	(166)	(775)
Balance, shares at Dec. 31, 2011		40,894,000	25,985,000				(59,000)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net loss	(56,085)				(56,085)
Other comprehensive loss	(272)					(272)
Issuance of shares of stock in conjunction with stock option exercises	153	1		152
Issuance of shares of stock in conjunction with stock option exercise, shares		78,000
Issuance of shares of stock and restricted stock, net of cancellations and tax withholdings	(157)	2		(159)
Issuance of shares of stock and restricted stock, net of cancellations and tax withholdings, shares		189,000
Common stock dividends	(2)				(2)
Non-cash equity compensation	3,932			3,932
Balance at Dec. 31, 2012	$ 95,516	$ 412	$ 260	$ 340,586	$ (244,529)	$ (438)	$ (775)
Balance, shares at Dec. 31, 2012		41,161,000	25,985,000				(59,000)