Stock-Based Compensation Plans (Stock-Based Compensation Expense By Statement Of Operations) (Details) (USD $)	3 Months Ended		9 Months Ended	12 Months Ended
	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2012	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Stock-based employee compensation expense related to employee stock options and emolyee stock purchases, pre tax	$ 2,200,000	$ 1,400,000	$ 4,900,000	$ 9,437,000	$ 7,548,000	$ 4,100,000
Research and Development
Stock-based employee compensation expense related to employee stock options and emolyee stock purchases, pre tax				4,107,000	3,343,000	1,544,000
General and Administrative
Stock-based employee compensation expense related to employee stock options and emolyee stock purchases, pre tax				$ 5,330,000	$ 4,205,000	$ 2,556,000