Stock-Based Compensation (Details) (USD $) In Thousands, except Share data, unless otherwise specified		1 Months Ended	12 Months Ended	1 Months Ended				12 Months Ended					12 Months Ended		1 Months Ended		12 Months Ended		1 Months Ended	12 Months Ended		12 Months Ended						1 Months Ended		1 Months Ended	12 Months Ended	1 Months Ended	12 Months Ended	1 Months Ended		12 Months Ended		12 Months Ended
	Dec. 31, 2011	Jan. 31, 2011 Officers	Dec. 31, 2011 Performance-conditioned awards	Jan. 31, 2011 Performance-conditioned awards Officers	Aug. 31, 2011 Time-vesting equity awards Officers	Jan. 31, 2011 Time-vesting equity awards with exercise price of 10.02 Officers	Jan. 31, 2011 Time-vesting equity awards with exercise price of 9.98 Officers	Dec. 31, 2011 Stock Options Y	Dec. 31, 2010 Stock Options Y	Dec. 31, 2009 Stock Options Y	Dec. 31, 2010 Stock Options Class A Common Stock	Dec. 31, 2009 Stock Options Class A Common Stock	Dec. 31, 2011 Stock Options Minimum	Dec. 31, 2011 Stock Options Maximum	Aug. 31, 2011 Stock Options Eligible employees and directors	Dec. 31, 2010 Stock Options Chief Executive Officer	Dec. 31, 2011 Stock Options Chief Executive Officer	Dec. 02, 2010 Stock Options Chief Executive Officer	Dec. 31, 2010 Stock Options Performance-conditioned awards Chief Executive Officer	Dec. 31, 2011 Stock Options Performance-conditioned awards Chief Executive Officer	Dec. 02, 2010 Stock Options Performance-conditioned awards Chief Executive Officer	Dec. 31, 2011 Stock Options Time-vesting equity awards	Dec. 31, 2011 Restricted Stock Units Y	Dec. 31, 2010 Restricted Stock Units	Dec. 31, 2009 Restricted Stock Units	Dec. 31, 2011 Restricted Stock Units Minimum	Dec. 31, 2011 Restricted Stock Units Maximum	Aug. 31, 2011 Restricted Stock Units Eligible employees and directors	Nov. 29, 2010 Restricted Stock Units Chief Executive Officer	Feb. 29, 2012 Restricted Stock Units Performance-conditioned awards	Dec. 31, 2011 Restricted Stock Units Performance-conditioned awards	Dec. 31, 2010 Restricted Stock Units Performance-conditioned awards Chief Executive Officer	Dec. 31, 2011 Restricted Stock Units Time-vesting equity awards	Dec. 31, 2011 Restricted Stock Units Time-vesting equity awards Chief Executive Officer	Dec. 31, 2010 Restricted Stock Units Time-vesting equity awards Chief Executive Officer	Dec. 31, 2011 Restricted Stock Units Time-vesting equity awards Chief Executive Officer anniversary	Dec. 31, 2011 Stock Options and Restricted Stock Units Performance-conditioned awards Chief Executive Officer	Dec. 31, 2011 Employee stock purchase plan Class A Common Stock	Dec. 31, 2010 Employee stock purchase plan Class A Common Stock	Dec. 31, 2009 Employee stock purchase plan Class A Common Stock	Dec. 31, 2006 Employee stock purchase plan Class A Common Stock	Dec. 31, 2011 2003 Incentive Compensation Plan
Share-based compensation arrangement by share-based payment award
Common stock authorized for awards under 2003 Incentive Compensation Plan (in shares)																																						1,000				13,500,000
The maximum employee contribution as a percentage of employee compensation																																						15.00%
Effective 2007, the discount from market price on the last day of offering period (as a percent)																																						15.00%
Prior to 2007, the discount from market price on the lower of the closing price of stock on either the first or last day of offering period (as a percent)																																									15.00%
Offering period (in months)																																						6 months
Shares issued																																						72	81	62
Issue price per share											$ 8.25	$ 12.88																										$ 8.50
Shares available for grant	1,596,000																													494								442
Premium percentage to market value of common stock on date of grant																	12.00%
Maximum term of awards (in years)			P10Y											P10Y		P10Y
Vesting period from first anniversary of grant (in years)						10 years	10 years						4 years	5 years						5 years						4 years	5 years			4 years				4 years
Portion of awards vesting each period (as a percent)																				20.00%										25.00%				25.00%		25.00%	20.00%
Vesting anniversaries subsequent to initial vesting on December 31, 2011																																				3
Number of shares to be settled in cash due to unavailability of sufficient shares under the plan for the delivery of the shares issuable upon exercise																						200											500
Number of shares to be purchased under options in share exchange program															4,918
Percentage of total number of options eligible for exchange in exchange offer															97.00%
Number of shares to be to be granted under options in share exchange program																												663
Minimum grant date exercise price (in dollars per share)																												$ 11.99
Number of Options
Options outstanding at the beginning of the period (in shares)								6,751,000
Granted (in shares)		475,000	1,000,000	113,000		113,000	250,000	2,661,000								1,000,000			1,000,000												1,000,000
Exercised (in shares)								(200,000)
Cancelled (in shares)								(5,344,000)
Options outstanding at the end of the period (in shares)								3,868,000	6,751,000
Options exercisable at the end of the period (in shares)								662,000																					1,000
Options expected to vest at the end of the period (in shares)								3,203,000
Weighted Average Remaining Contract Term (Years)
Options outstanding - weighted average remaining contract term (in years)								8.3	6.0
Options exercisable - weighted average remaining contract term (in years)								5.0
Options expected to vest - weighted average remaining contract term (in years)								9.0
Weighted Average Exercise Price
Weighted average exercise price of options outstanding (in dollars per share)								$ 9.67	$ 20.72
Exercise price of options granted (in dollars per share)						$ 10.02	$ 9.98	$ 8.69										$ 9.00			$ 8.06
Exercise price (in dollars per share)								$ 7.40
Cancelled - weighted average exercise price (in dollars per share)								$ 23.23
Options exercisable - weighted average exercise price (in dollars per share)								$ 13.48
Options expected to vest - weighted average exercise price (in dollars per share)								$ 8.87
Aggregate Intrinsic Value
Aggregate intrinsic value of options exercised (in dollars)								$ 344	$ 1,276	$ 7,724
Aggregate intrinsic value of options outstanding (in dollars)								3,876	1,814
Options Exercisable - aggregate intrinsic value (in dollars)								714
Options expected to vest - aggregate intrinsic value (in dollars)								3,161
Weighted-average grant date fair value of options granted (in dollars per share)								$ 4.10	$ 3.63	$ 5.85
Assumptions:
Expected volatility (as a percent)								52.00%	51.00%	47.00%
Risk-free interest rate (as a percent)								1.90%	2.60%	2.30%
Expected life (in years)								6	6	6
Stock-based compensation, additional disclosures
Stock-based compensation expense recognized (in dollars)					363			6,300	7,300	11,400													15,200	15,400	23,000
Tax benefit recognized related to stock based compensation expenses (in dollars)								2,400	2,700	4,200													5,700	5,800	9,000
Unrecognized stock-based compensation expense relating to unvested awards that will be amortized (in dollars)								11,700															37,700
Weighted-average period of amortization (in years)								2															2
Fair value at vesting date																							8,600	7,000	16,000
Cash received from exercise of stock options								529
Actual tax benefit realized for the tax deductions from option exercise of the stock based payment arrangements								$ 195
Number of Restricted Stock Units
Unvested units outstanding at the beginning of the period (in shares)																							2,440,000
Granted (in shares)																							3,341,000									1,000,000			1,000,000
Vested (in shares)																							(912,000)
Cancelled (in shares)																							(98,000)
Unvested units outstanding at the end of the period (in shares)																							4,771,000	2,440,000
Weighted Average Grant Date Fair Value
Unvested units outstanding at the beginning of the period (in dollars per share)																							$ 15.13
Granted (in dollars per share)																							$ 8.52	$ 12.74	$ 12.77
Vested (in dollars per share)																							$ 15.37
Cancelled (in dollars per share)																							$ 13.58
Unvested units outstanding at the end of the period (in dollars per share)																							$ 10.49	$ 15.13