CONSOLIDATED STATEMENTS OF SHAREHOLDERS' EQUITY (USD $) In Thousands, except Share data	Total	Common Class A Member	Common Class B Member	Additional Paid In Capital Member	Retained Earnings Member	Accumulated Other Comprehensive Income (Loss) Member
Opening Balance VALUE at Dec. 31, 2008	$ 100,257	$ 295	$ 76	$ 582,325	$ (467,177)	$ (15,262)
Opening Balance SHARES at Dec. 31, 2008		29,479,188	7,607,532
Conversion of Class B common stock to Class A common stock SHARES		150,000	(150,000)
Compensation expense related to granting of stock options SHARES		0	0
Compensation expense related to granting of restricted stock units SHARES		796,824	0
Issuance of common stock related to an incentive plan SHARES		74,369	0
Common stock repurchase SHARES		(662,664)	0
Exercise of stock options SHARES		0	0
Purchase of vested employee restricted stock units SHARES		(82,556)	0
Net income (loss)	5,398	0	0	0	5,398	0
Conversion of Class B common stock to Class A common stock VALUE	0	1	(1)	0	0	0
Compensation expense related to granting of stock options VALUE	485	0	0	485	0	0
Compensation expense related to granting of restricted stock units VALUE	6,388	8	0	6,380	0	0
Issuance of common stock related to an incentive plan VALUE	97	0	0	97	0	0
Common stock repurchase VALUE	(889)	(7)	0	(882)	0	0
Purchase of vested employee restricted stock units	(104)	0	0	(104)	0	0
Forfeitures of dividend equivalents VALUE	169	0	0	0	169	0
Realization of tax benefit for dividend equivalent payments VALUE	321	0	0	321	0	0
Exercise of stock options VALUE	0	0	0	0	0	0
Net unrealized gain (loss) on investments VALUE	0	0	0	0	0	0
Net unrealized gain (loss) on derivatives VALUE	1,830	0	0	0	0	1,830
Ending Balance VALUE at Dec. 31, 2009	113,952	297	75	588,622	(461,610)	(13,432)
Ending Balance SHARES at Dec. 31, 2009		29,755,161	7,457,532
Conversion of Class B common stock to Class A common stock SHARES		90,000	(90,000)
Compensation expense related to granting of stock options SHARES		0	0
Compensation expense related to granting of restricted stock units SHARES		941,213	0
Issuance of common stock related to an incentive plan SHARES		0	0
Common stock repurchase SHARES		0	0
Exercise of stock options SHARES		97,725	0
Purchase of vested employee restricted stock units SHARES		(183,531)	0
Net income (loss)	46,436	0	0	0	46,436	0
Conversion of Class B common stock to Class A common stock VALUE	0	1	(1)	0	0	0
Compensation expense related to granting of stock options VALUE	549	0	0	549	0	0
Compensation expense related to granting of restricted stock units VALUE	4,979	10	0	4,969	0	0
Issuance of common stock related to an incentive plan VALUE	0	0	0	0	0	0
Common stock repurchase VALUE	0	0	0	0	0	0
Purchase of vested employee restricted stock units	(1,628)	(2)	0	(1,626)	0	0
Forfeitures of dividend equivalents VALUE	94	0	0	0	94	0
Realization of tax benefit for dividend equivalent payments VALUE	0	0	0	0	0	0
Exercise of stock options VALUE	130	1	0	129	0	0
Net unrealized gain (loss) on derivatives VALUE	6,155	0	0	0	0	6,155
Ending Balance VALUE at Dec. 31, 2010	170,667	307	74	592,643	(415,080)	(7,277)
Ending Balance SHARES at Dec. 31, 2010		30,700,568	7,367,532
Conversion of Class B common stock to Class A common stock SHARES		170,000	(170,000)
Compensation expense related to granting of stock options SHARES	0	0	0
Compensation expense related to granting of restricted stock units SHARES		416,906	0
Issuance of common stock related to an incentive plan SHARES		0	0
Common stock repurchase SHARES		0	0
Exercise of stock options SHARES	(53,625)	53,625	0
Purchase of vested employee restricted stock units SHARES		(297,098)	0
Net income (loss)	68,510	0	0	0	68,510	0
Conversion of Class B common stock to Class A common stock VALUE	0	2	(2)	0	0	0
Compensation expense related to granting of stock options VALUE	462	0	0	462	0	0
Compensation expense related to granting of restricted stock units VALUE	7,209	4	0	7,205	0	0
Issuance of common stock related to an incentive plan VALUE	0	0	0	0	0	0
Common stock repurchase VALUE	0	0	0	0	0	0
Purchase of vested employee restricted stock units	(3,057)	(3)	0	(3,054)	0	0
Payments of dividends VALUE	0	0	0	0	0	0
Forfeitures of dividend equivalents VALUE	5	0	0	0	5	0
Exercise of stock options VALUE	71	0	0	71	0	0
Net unrealized gain (loss) on investments VALUE	0	0	0	0	0	0
Net unrealized gain (loss) on derivatives VALUE	7,277	0	0	0	0	7,277
Ending Balance VALUE at Dec. 31, 2011	$ 251,144	$ 310	$ 72	$ 597,327	$ (346,565)	$ 0
Ending Balance SHARES at Dec. 31, 2011		31,044,001	7,197,532