Stock-Based Compensation (Schedule of Restricted Stock Units by Type) (Details) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Total restricted stock units vesting conditions granted	3,151	3,553	2,721
Restricted Stock Units Service Based [Member]
Restricted stock units vesting conditions granted	2,782	3,003	1,597
Restricted Stock Units Performance Based [Member]
Restricted stock units granted with performance based vesting	369	550	1,124