Stock Based Compensation (Narrative) (Details) (USD $)	12 Months Ended		12 Months Ended			0 Months Ended	12 Months Ended
	Dec. 31, 2010	Dec. 31, 2011	Dec. 31, 2011 Restricted Stock Units (RSUs) [Member] years	Dec. 31, 2010 Restricted Stock Units (RSUs) [Member]	Dec. 31, 2009 Restricted Stock Units (RSUs) [Member]	Jun. 07, 2010 Stock Options [Member]	Dec. 31, 2010 Stock Options [Member]	Dec. 31, 2009 Stock Options [Member]	Dec. 31, 2011 Employee [Member] Restricted Stock Units (RSUs) [Member] years	Dec. 31, 2011 Director [Member] Restricted Stock Units (RSUs) [Member] years	Jun. 15, 2010 Stock Option Exchange Program [Member] Restricted Stock Units (RSUs) [Member] years
Number of shares authorized for stock based employee and non-employee compensation plans		11,900,000
Options surrendered and cancelled in conjunction with stock option exchange program	4,400,000
RSUs granted				1,200,000
Expected volatility rate used to estimate the fair value of surrendered options						70.00%
Expected dividend yield used to estimate the fair value of surrendered options						5.00%
Compensation expense recognized			$ 11,200,000	$ 9,000,000	$ 7,300,000		$ 820,000	$ 2,600,000
RSUs, annual vesting percentage									20.00%	100.00%
RSUs, vesting period (in years)									5	1
RSUs, contractual lives (in years)									5	1
RSUs, vesting period, minimum (in years)											1
RSUs, vesting period, maximum (in years)											2
Total unrecognized compensation expense			$ 14,500,000
Total unrecognized compensation expense, weighted average recognition period			3.2