Stock Plans (Details) (USD $)	12 Months Ended			12 Months Ended								12 Months Ended			9 Months Ended	12 Months Ended	9 Months Ended	12 Months Ended		12 Months Ended							0 Months Ended				12 Months Ended					12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2012 Price Range 10.44-10.44 [Member]	Dec. 31, 2012 Price Range 11.90-14.15 [Member]	Dec. 31, 2012 Price Range 10.44-14.15 [Member]	Dec. 31, 2012 Director [Member]	Dec. 31, 2011 Director [Member]	Dec. 31, 2010 Director [Member]	Dec. 31, 2012 All Employees and Senior Management [Member]	Jul. 02, 2010 All Employees and Senior Management [Member]	Dec. 31, 2010 All Employees [Member]	Dec. 31, 2010 Senior Management [Member]	Dec. 31, 2010 Chair of Audit Committee [Member]	Sep. 30, 2010 Chair of Compensations Committee [Member]	Dec. 31, 2010 Chair of Compensations Committee [Member]	Sep. 30, 2010 Chair of Nominating and Corporate Governance Committee [Member]	Dec. 31, 2010 Chair of Nominating and Corporate Governance Committee [Member]	Dec. 31, 2012 All Plans [Member]	Dec. 31, 2012 Performance Shares [Member]	Dec. 31, 2012 Restricted Stock [Member]	Dec. 31, 2011 Restricted Stock [Member]	Dec. 31, 2010 Restricted Stock [Member]	Dec. 31, 2012 1996 Equity Incentive Plan [Member]	Dec. 31, 2012 2000 Equity Incentive Plan [Member]	Dec. 31, 2012 2009 Equity Incentive Plans [Member]	Dec. 31, 2012 Stock Options [Member]	Dec. 31, 2011 Stock Options [Member]	Dec. 31, 2010 Stock Options [Member]	Dec. 31, 2009 Stock Options [Member]	Dec. 31, 2012 Stock Options [Member]	Dec. 31, 2011 Stock Options [Member]	Dec. 31, 2010 Stock Options [Member]	Dec. 31, 2011 Directors' Equity Plan [Member]	Dec. 31, 2012 Directors' Equity Plan [Member]	Dec. 31, 2010 Directors' Equity Plan [Member] Director [Member]	Dec. 31, 2012 Directors' Equity Plan [Member] Director [Member]	Dec. 31, 2012 Deferred Fee Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total number of stock-based compensation plan																			5
Number of stock-based compensation plans under which no further awards may be granted (the EIP)																			3
Shares available for grant under the plans (in shares)																																			1,422,992			540,761
Shares authorized for grant under the plans (in shares)							12,540,761																			10,000,000											2,540,761
Shares available for grant under two plans (in shares)							2,169,089																			746,097
Compensation expense							$ 800,000	$ (600,000)	$ 1,700,000											$ 400,000	$ 15,900,000	$ 14,800,000	$ 12,800,000
Cash compensation							700,000	700,000	500,000
Number of shares issued (in shares)																				930,020	3,976,000	1,734,000	3,264,000
Stock outstanding (in shares)																					7,049,000														137,709
Compensation expense							800,000	(600,000)	1,700,000											400,000	15,900,000	14,800,000	12,800,000
1996, 2000, and 2009 equity incentive plans [Abstract]
Plan expiration dates																								May 22, 2006	May 14, 2009	May 14, 2019
Expiry period of awards granted (in years)																								May 22, 2006	May 14, 2009	May 14, 2019
Effective date of award																										May 14, 2009
Measurement period																				3 years
Period considered for evaluating performance metrics																				90 days
Number of shares granted (in shares)																				930,020	3,976,000	1,734,000	3,264,000
Expense recognized during the period							800,000	(600,000)	1,700,000											400,000	15,900,000	14,800,000	12,800,000
Shares Subject to Option [Roll forward]
Balance at beginning of period (in shares)																															895,000	1,507,000	3,551,000
Options granted (in shares)																															0	0	0
Options exercised (in shares)																															0	(10,000)	0
Options canceled, forfeited or lapsed (in shares)																															(355,000)	(602,000)	(2,044,000)
Balance at end of period (in shares)																											540,000	895,000	1,507,000	3,551,000	540,000	895,000	1,507,000
Weighted Average Option Price Per Share [Abstract]
Balance at beginning of period (in dollars share)																															$ 9.94	$ 10.50	$ 13.74
Options granted (in dollars per share)																															$ 0	$ 0	$ 0
Options exercised (in dollars per share)																															$ 0	$ 8.19	$ 0
Options canceled, forfeited or lapsed (in dollars per share)																															$ 8.35	$ 10.86	$ 16.13
Balance at end of period (in dollars per share)																											$ 10.99	$ 9.94	$ 10.50	$ 13.74	$ 10.99	$ 9.94	$ 10.50
Number Outstanding (in shares)				428,000	112,000	540,000
Range of Exercise Prices, lower limit (in dollars per share)				$ 10.44	$ 11.90	$ 10.44
Range of Exercise Prices, upper limit (in dollars per share)				$ 10.44	$ 14.15	$ 14.15
Weighted Average Exercise Price (in dollars per share)				$ 10.44	$ 13.12	$ 10.99
Weighted Average Remaining Life				0 years 4 months 24 days	2 years 7 months 6 days	0 years 10 months 24 days
Weighted Average Remaining Life [Abstract]
Balance at beginning of period																											0 years 10 months 24 days	1 year 3 months 18 days	1 year 8 months 12 days	1 year 6 months
Balance at end of period																											0 years 10 months 24 days	1 year 3 months 18 days	1 year 8 months 12 days	1 year 6 months
Aggregate Intrinsic Value [Abstract]
Balance at beginning of period																															0	603,000	0
Options exercised																																12,000
Balance at end of period																											0	0	603,000	0	0	0	603,000
Number of Shares [Roll Forward]
Balance at beginning of period (in shares)																					4,847,000	4,440,000	2,193,000
Restricted stock granted (in shares)										1,911,000											3,976,000	1,734,000	3,264,000
Restricted stock vested (in shares)																					(1,387,000)	(1,146,000)	(874,000)
Restricted stock forfeited (in shares)																					(387,000)	(181,000)	(143,000)
Balance at end of period (in shares)																					7,049,000	4,847,000	4,440,000
Weighted Average Grant Date Fair Value [Abstract]
Balance at beginning of period (in dollars per shares)																					$ 8.40	$ 8.29	$ 10.41
Restricted stock granted (in dollars per shares)																					$ 4.18	$ 9.38	$ 7.54
Restricted stock vested (in dollars per shares)																					$ 8.78	$ 9.52	$ 10.86
Restricted stock forfeited (in dollars per shares)																					$ 5.99	$ 7.99	$ 7.95
Balance at end of period (in dollars per shares)																					$ 6.08	$ 8.40	$ 8.29
Aggregate Fair Value [Abstract]
Balance at beginning of period																					24,962,000	43,199,000	17,126,000
Restricted stock granted																					17,017,000	8,930,000	31,760,000
Restricted stock vested																					5,937,000	5,899,000	8,507,000
Balance at end of period																					30,169,000	24,962,000	43,199,000
Unvested restricted stock [Abstract]
Restricted stock granted (in shares)										1,911,000											3,976,000	1,734,000	3,264,000
Fair value of restricted stock granted											14,200,000
Number of installments that restricted shares granted will vest													3 years
Vesting period of stocks granted												third anniversary of the grant date
Percentage of stock granted to all employees that vest on the third anniversary of the grant date (in hundredths)												100.00%
Remaining unrecognized compensation cost associated with unvested restricted stock awards																					24,800,000
Weighted average period over which unvested restricted stock awards unrecognized compensation cost is expected to be recognized																					1 year 6 months
Non Employee Directors' Compensation Plans [Abstract]
Number of stock options award received by each non-employee director (in shares)																															0	0	0
Exercisable period of stock options granted, minimum													3 years
Exercisable period of stock options granted, maximum													3 years
Annual stipend received by chair of committees														20,000	20,000	20,000	7,500	10,000
Annual retainer for non employee directors in cash		75,000
Annual retainer for non employee directors cash value of stock units		75,000
Time period when fees were paid to non-employee directors		quarterly
Cash value of the fees payable to the director as a percentage of closing prices of common stock (in hundredths)		85.00%
Basis of converting directors stock unit		one-to-one
Number of directors participating in the plan during the period	10
Plan units earned during the period (in shares)	306,634																																	197,600		95,695
Plan units granted during the period (in shares)																																				30,000
Options Outstanding [Abstract]
Balance at beginning of period (in dollars share)																															$ 9.94	$ 10.50	$ 13.74
Options granted (in dollars per share)																															$ 0	$ 0	$ 0
Options exercised (in dollars per share)																															$ 0	$ 8.19	$ 0
Options canceled, forfeited or lapsed (in dollars per share)																															$ 8.35	$ 10.86	$ 16.13
Balance at end of period (in dollars per share)																											$ 10.99	$ 9.94	$ 10.50	$ 13.74	$ 10.99	$ 9.94	$ 10.50
Number Outstanding (in shares)				428,000	112,000	540,000
Range of Exercise Prices, lower limit (in dollars per share)				$ 10.44	$ 11.90	$ 10.44
Range of Exercise Prices, upper limit (in dollars per share)				$ 10.44	$ 14.15	$ 14.15
Weighted Average Exercise Price (in dollars per share)				$ 10.44	$ 13.12	$ 10.99
Weighted Average Remaining Life				0 years 4 months 24 days	2 years 7 months 6 days	0 years 10 months 24 days
Options Exercisable [Abstract]
Number Exercisable (in shares)				428,000	112,000	540,000
Weighted Average Exercise Price (in dollars per share)				$ 10.44	$ 13.12	$ 10.99
Number of options exercisable at end of period (in shares)		895,000	1,507,000
Weighted average exercise price of exercisable options (in dollars per share)	$ 11.64	$ 9.94	$ 10.50
Cash received upon exercise of options during the period		$ 100,000