XML 47 R47.htm IDEA: XBRL DOCUMENT v2.4.0.6
Stockholders' Equity (Summary Of Anti-Dilutive Options Excluded) (Details) (USD $)
12 Months Ended
Dec. 31, 2011
Dec. 31, 2010
Dec. 31, 2009
Stockholders' Equity [Abstract]      
Options to purchase shares of common stock 704,384 5,328,246 5,255,120
Weighted-average exercise prices of options $ 32.05 $ 23.94 $ 23.57