Stock Incentive Plan (Schedule of Nonvested Restricted Stock Units Activity) (Details) (Restricted Stock Units (RSUs) [Member])	12 Months Ended
	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009
Restricted Stock Units (RSUs) [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested [Roll Forward]
RSU's granted and unvested at beginning of period	4,945,375	3,713,025	4,971,231
Granted	107,500	2,310,650	119,500
Vested	(576,050)	(916,750)	(1,287,943)
Cancelled	(105,850)	(161,550)	(89,763)
RSU's granted and unvested at end of period	4,370,975	4,945,375	3,713,025
Vesting period	5 years
Deferred	2,641,177