Stock-Based Compensation (Details) (USD $) In Thousands, except Share data, unless otherwise specified			3 Months Ended			6 Months Ended			6 Months Ended		1 Months Ended				1 Months Ended	3 Months Ended			6 Months Ended				1 Months Ended
	Jun. 30, 2011	Dec. 31, 2010	Jun. 30, 2011 Stock Options	Mar. 31, 2011 Stock Options	Jun. 30, 2010 Stock Options	Jun. 30, 2011 Stock Options	Jun. 30, 2010 Stock Options	Dec. 31, 2010 Stock Options	Jun. 30, 2011 Stock Options Performance-conditioned awards	Jun. 30, 2011 Stock Options Performance-conditioned awards Chief Executive Officer	Jan. 31, 2011 Stock Options Performance-conditioned awards Officers	Jan. 31, 2011 Stock Options Time-vesting equity awards Officers	Dec. 31, 2010 Stock Options Chief Executive Officer	Dec. 02, 2010 Stock Options Chief Executive Officer	Jan. 31, 2011 Stock Options Officers	Jun. 30, 2011 Restricted Stock Units	Mar. 31, 2011 Restricted Stock Units	Jun. 30, 2010 Restricted Stock Units	Jun. 30, 2011 Restricted Stock Units	Jun. 30, 2010 Restricted Stock Units	Jun. 30, 2011 Restricted Stock Units Performance-conditioned awards Chief Executive Officer	Jun. 30, 2011 Restricted Stock Units Time-vesting equity awards	Dec. 31, 2011 Restricted Stock Units Chief Executive Officer	Dec. 31, 2010 Restricted Stock Units Chief Executive Officer	Jul. 31, 2011 Eligible employees and directors	Jul. 19, 2011 Eligible employees and directors
Stock-Based Compensation
Shares available for grant (in shares)	972	2,119
Number of options
Options outstanding at the beginning of the period (in shares)			7,196,000	6,751,000		6,751,000
Granted (in shares)			20,000	754,000						1,000,000	113,000		1,000,000		475,000
Exercised (in shares)			(2,000)	(2,000)
Cancelled (in shares)			(51,000)	(307,000)
Options outstanding at the end of the period (in shares)			7,163,000	7,196,000		7,163,000
Options exercisable at the end of the period (in shares)			4,444,000			4,444,000
Weighted average remaining contract term
Options outstanding - weighted average remaining contract term (in years)			6.1	6.4		6.1		6.0
Options exercisable - weighted average remaining contract term (in years)			4.5
Weighted average exercise price per share
Options outstanding at the beginning of the period - Weighted average exercise price (in dollars per share)			$ 19.42	$ 20.72		$ 20.72
Granted - weighted average exercise price (in dollars per share)										$ 8.06				$ 9
Exercised - weighted average exercise price (in dollars per share)																										$ 11.99
Options outstanding at the end of the period - Weighted average exercise price (in dollars per share)			$ 19.41	$ 19.42		$ 19.41
Options exercisable - weighted average exercise price (in dollars per share)			$ 23.36			$ 23.36
Number of weeks for calculation of share stock price																									52
Aggregate intrinsic value
Options outstanding at the beginning of the period - Aggregate intrinsic value (in dollars)			$ 654	$ 1,814		$ 1,814
Exercised - Aggregate intrinsic value (in dollars)			11	15
Options outstanding at the end of the period - Aggregate intrinsic value (in dollars)			3,288	654		3,288
Options Exercisable - aggregate intrinsic value (in dollars)			1,132			1,132
Weighted-average grant date fair value of options granted (in dollars per share)			$ 4.61	$ 4.62
Compensation expense, tax benefit and unearned compensation
Stock-based compensation expense recognized (in dollars)			1,700		2,100	3,400	4,000									3,300		3,300	6,200	8,500
Tax benefit recognized related to stock based compensation expenses (in dollars)			630		700	1,260	1,300									1,240		1,300	2,240	3,300
Unearned compensation that will be amortized (in dollars)			$ 13,900			$ 13,900										$ 32,300			$ 32,300
Weighted-average period of amortization (in years)			2													2
Number of restricted shares
Non-vested units outstanding at the beginning of the period (in shares)																2,859,000	2,440,000		2,440,000
Granted (in shares)																32,000	917,000				1,000,000			1,000,000
Vested (in shares)																(44,000)	(482,000)
Cancelled (in shares)																(26,000)	(16,000)
Non-vested units outstanding at the end of the period (in shares)																2,821,000	2,859,000		2,821,000
Weighted Average Grant Date Fair Value
Non-vested units outstanding at the beginning of the period (in dollars per share)																$ 12.58	$ 15.13		$ 15.13
Granted (in dollars per share)																$ 9.47	$ 8.92
Vested (in dollars per share)																$ 25.31	$ 18.43
Cancelled (in dollars per share)																$ 13.66	$ 15.52		$ 13.66
Non-vested units outstanding at the end of the period (in dollars per share)																$ 12.34	$ 12.58		$ 12.34
Maximum term of awards						10Y						10Y	10Y
Exercisable period, minimum (in years)						4
Exercisable period, maximum (in years)						5
Number of installments for vesting of RSUs, minimum																			4
Number of installments for vesting of RSUs, maximum																			5
Common stock authorized for awards under 2003 Incentive Compensation Plan	13,500
Approximate percentage of premium to the market value of the entity's stock (as a percent)													12.00%
Vesting period																					5Y			4Y
Portion of awards vested (as a percent)										20%											20%		25%
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 (in shares)									200													500
Grants in period with a specified exercise price (in shares)												113
Additional grants in period with a specified exercise price (in shares)												250
Grants in period with a specified exercise price (in dollars per share)												$ 10.02
Additional grants in period with a specified exercise price (in dollars per share)												$ 9.98