Consolidated Statements of Stockholders' Equity (Deficit) (USD $) In Thousands, except Share data	Total	Additional Paid-in Capital [Member]	Accumulated Deficit [Member]	Accumulated Other Comprehensive Income (Loss) [Member]	Class A common stock [Member]	Class B common stock [Member]	Class U common stock [Member]
Balance, Beginning at Dec. 31, 2010	$ 10,357	$ 941,171	$ (930,822)		$ 5	$ 2	$ 1
Balance, Beginning, Shares at Dec. 31, 2010					52,978,304	22,188,161	9,352,729
Issuance of common stock upon exercise of stock options or awards of restricted stock units	41	41
Issuance of common stock upon exercise of stock options or awards of restricted stock units, Shares	25,000				536,465
Stock-based compensation expense	2,343	2,343
Dividends paid	(5,102)	(5,102)
Change in fair value of interest rate swap agreements	0
Net income (loss)	(8,200)		(8,200)
Balance, Ending at Dec. 31, 2011	(561)	938,453	(939,022)		5	2	1
Balance, Ending, Shares at Dec. 31, 2011					53,514,769	22,188,161	9,352,729
Issuance of common stock upon exercise of stock options or awards of restricted stock units	23	23
Issuance of common stock upon exercise of stock options or awards of restricted stock units, Shares	50,000				889,457
Stock-based compensation expense	2,651	2,651
Dividends paid	(10,313)	(10,313)
Change in fair value of interest rate swap agreements	0
Net income (loss)	13,601		13,601
Balance, Ending at Dec. 31, 2012	5,401	930,814	(925,421)		5	2	1
Balance, Ending, Shares at Dec. 31, 2012					54,404,226	22,188,161	9,352,729
Issuance of common stock upon exercise of stock options or awards of restricted stock units	2,807	2,806			1
Issuance of common stock upon exercise of stock options or awards of restricted stock units, Shares	1,683,000				2,170,438
Stock-based compensation expense	4,771	4,771
Class B common stock exchanged for Class A common stock					3,218,939	(3,218,939)
Dividends paid	(11,014)	(11,014)
Change in fair value of interest rate swap agreements	234			234
Net income (loss)	133,825		133,825
Balance, Ending at Dec. 31, 2013	$ 136,024	$ 927,377	$ (791,596)	$ 234	$ 6	$ 2	$ 1
Balance, Ending, Shares at Dec. 31, 2013					59,793,603	18,969,222	9,352,729