Consolidated Statement of Stockholders' Equity and Comprehensive Income(loss) (USD $) In Thousands, unless otherwise specified	Common Class A [Member]	Common Class B [Member]	Additional Paid-in Capital [Member]	Treasury Stock [Member]	Accumulated Other Comprehensive Income (Loss) [Member]	Retained Earnings [Member]	Total
Balances at Dec. 31, 2008	$ 135	$ 24	$ 91,912	$ (21,007)		$ 47,756	$ 118,820
Net income (loss)						(25,030)	(25,030)
Other comprehensive loss:
Unrealized gain on effective portion of fuel hedge, net of tax					305		305
Comprehensive income (loss)					305	(25,030)	(24,725)
Stock-based employee compensation cost			595				595
Issuance of restricted stock	1		(1,828)	1,812			(15)
Balances at December 31, 2011 at Dec. 31, 2009	136	24	90,679	(19,195)	305	22,726	94,675
Net income (loss)						3,289	3,289
Other comprehensive loss:
Unrealized gain on effective portion of fuel hedge, net of tax					1,938		1,938
Comprehensive income (loss)					1,938	3,289	5,227
Reclassification of fuel hedge gain into statement of operations, net of tax					(1,767)		(1,767)
Stock-based employee compensation cost			1,018				1,018
Issuance of restricted stock	2		(2,582)	2,396			(184)
Exercise of stock options	2		1,306				1,308
Income tax benefit arising from exercise of stock options and restricted stock vesting			421				421
Balances at December 31, 2011 at Dec. 31, 2010	140	24	90,842	(16,799)	476	26,015	100,698
Net income (loss)						(14,267)	(14,267)
Other comprehensive loss:
Unrealized gain on effective portion of fuel hedge, net of tax					1,500		1,500
Comprehensive income (loss)					1,500	(14,267)	(12,767)
Reclassification of fuel hedge gain into statement of operations, net of tax					(1,926)		(1,926)
Stock-based employee compensation cost			1,026				1,026
Issuance of restricted stock	3		(2,765)	2,354			(408)
Income tax benefit arising from exercise of stock options and restricted stock vesting			432				432
Balances at December 31, 2011 at Dec. 31, 2011	$ 143	$ 24	$ 89,535	$ (14,445)	$ 50	$ 11,748	$ 87,055