Stockholders' Equity (Details) (USD $)	3 Months Ended		6 Months Ended
	Jun. 30, 2012	Jun. 30, 2011	Jun. 30, 2012	Jun. 30, 2011	Dec. 31, 2011	Jul. 28, 2004
Changes in the components of stockholders equity
Balance at the beginning of the period			$ 44,949,000
Net earnings	5,018,000	3,901,000	2,395,000	335,000
Unrealized gain on available-for-sale securities, net of income tax expense	(7,000)		16,000	5,000
Change in net actuarial loss and prior service cost, net of income tax expense	(12,000)	(418,000)	(24,000)	(445,000)
Balance at the end of the period	47,526,000		47,526,000
Accumulated other comprehensive loss, net of income taxes
Net actuarial loss and prior service cost not yet recognized in net periodic benefit cost, net of income tax benefit	(2,234,000)		(2,234,000)		(2,258,000)
Accumulated unrealized gain (loss) on available-for-sale securities, net of income tax (expense) benefit	8,000		8,000		(8,000)
Accumulated other comprehensive loss	(2,226,000)		(2,226,000)		(2,266,000)
Income tax benefit on net actuarial loss and prior service cost not yet recognized in net periodic benefit cost	1,534,000		1,534,000		1,550,000
Income tax (expense) benefit on accumulated unrealized gain (loss) on available-for-sale securities	6,000		6,000		4,000
Number of shares of common stock authorized to be repurchased						2,000,000
Remaining number of shares authorized to be repurchased	1,634,607		1,634,607
Number of shares purchased and retired			23,779	29,575
Average purchase price of shares purchased and retired (in dollars per share)			$ 1.16	$ 1.76
Common stock
Changes in the components of stockholders equity
Balance at the beginning of the period			1,828,000
Issuance of restricted stock awards, net of forfeitures			12,000
Repurchase and retirement of common stock			(2,000)
Balance at the end of the period	1,838,000		1,838,000
Class A Common Stock
Changes in the components of stockholders equity
Balance at the beginning of the period					1,851,000
Balance at the end of the period	1,851,000		1,851,000		1,851,000
Additional Paid-in Capital
Changes in the components of stockholders equity
Balance at the beginning of the period			101,888,000
Issuance of restricted stock awards, net of forfeitures			(12,000)
Stock-based compensation			169,000
Repurchase and retirement of common stock			(25,000)
Balance at the end of the period	102,020,000		102,020,000
Accumulated Deficit
Changes in the components of stockholders equity
Balance at the beginning of the period			(58,352,000)
Net earnings			2,395,000
Balance at the end of the period	(55,957,000)		(55,957,000)
Accumulated Other Comprehensive Loss
Changes in the components of stockholders equity
Balance at the beginning of the period			(2,266,000)
Unrealized gain on available-for-sale securities, net of income tax expense			16,000
Change in net actuarial loss and prior service cost, net of income tax expense			24,000
Balance at the end of the period	(2,226,000)		(2,226,000)
Income tax expense on unrealized gain on available-for-sale securities			10,000
Income tax expense on change in net actuarial loss and prior service cost			$ 16,000