Stock Plans (Details) (USD $)	3 Months Ended			12 Months Ended
	Mar. 31, 2013		Mar. 31, 2012	Dec. 31, 2012	Feb. 27, 2013
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of stock-based compensation plan under which grants were made	5
Shares authorized for grant under the plans (in shares)	12,540,761
Shares available for grant under the plan (in shares)	2,002,671
Number of Shares [Roll Forward]
Balance at beginning of period (in shares)	7,049,000
Restricted stock granted (in shares)	521,000	[1]	3,667,000
Restricted stock vested (in shares)	(1,806,000)
Restricted stock forfeited (in shares)	(422,000)
Balance at end of period (in shares)	5,342,000			7,049,000
Weighted Average Grant Date Fair Value [Abstract]
Balance at beginning of period (in dollars per shares)	$ 6.08
Restricted stock granted (in dollars per shares)	$ 4.09	[1]	4.22
Restricted stock vested (in dollars per shares)	$ 6.50
Restricted stock forfeited (in dollars per shares)	$ 5.69
Balance at end of period (in dollars per shares)	$ 5.77			6.08
Aggregate Fair Value [Abstract]
Balance at beginning of period	$ 30,169,000
Restricted stock granted	2,077,000	[1]	15,300,000
Restricted stock vested	7,205,000		4,700,000
Balance at end of period	21,316,000		30,700,000	30,169,000
Shares Subject to Option [Roll forward]
Balance at beginning of period (in shares)	540,000
Options granted (in shares)	0
Options exercised (in shares)	0
Options canceled, forfeited or lapsed (in shares)	(14,000)
Balance at end of period (in shares)	526,000			540,000
Exercisable at end of period (in shares)	526,000
Weighted Average Option Price Per Share [Abstract]
Balance at beginning of period (in dollars per share)	$ 10.99
Options granted (in dollars per share)	$ 0
Options exercised (in dollars per share)	$ 0
Options canceled, forfeited or lapsed (in dollars per share)	$ 12.30
Balance at end of period (in dollars per share)	$ 10.96			10.99
Exercisable at end of period (in dollars per share)	$ 10.96			10.99
Weighted Average Remaining Life in Years [Abstract]
Balance at beginning of period	7 months 6 days			10 months 24 days
Balance at end of period	7 months 6 days			10 months 24 days
Exercisable at end of period	7 months 6 days
Aggregate Intrinsic Value [Abstract]
Balance at beginning of period	0
Balance at end of period	0			0
Exercisable at end of period	0
Performance Shares [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Measurement period			3 years
Initial period over which target number of performance shares are awarded				90 days
Number of shares granted (in shares)			930,020
Expense recognized during the period	300,000
Shares authorized for grant under the plans (in shares)					1,123,966
Restricted Stock [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares authorized for grant under the plans (in shares)					2,845,000
Aggregate Fair Value [Abstract]
Remaining unrecognized compensation cost associated with unvested restricted stock awards	$ 22,900,000
Weighted average period over which unvested restricted stock awards unrecognized compensation cost is expected to be recognized (in years)	2 years

[1] Amount excludes 2,845,000 restricted shares approved by the Compensation Committee on February 27, 2013. These restricted stock awards approved in February 2013 will be granted upon stockholder approval of the Company's 2013 Equity Incentive Plan at the Annual Meeting of Stockholders to be held on May 8, 2013.