Stock Benefit Plan (Awards Granted To Employees And Non-Employee Directors) (Details)	12 Months Ended
	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009
2011 Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Available for Future Grant of Awards	2,931,962
Employee Awards [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Restricted Stock Granted	87,913	108,252	114,078
Employee Awards [Member] | 1994 Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock Options Granted	1,542,381
Total Granted	1,542,381
Employee Awards [Member] | 2000 Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock Options Granted	2,101,220
Restricted Stock Granted	350,702
Total Granted	2,451,922
Employee Awards [Member] | 2003 Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock Options Granted	2,737,142
Restricted Stock Granted	96,822
Total Granted	2,833,964
Employee Awards [Member] | 2008 Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock Options Granted	1,354,837
Restricted Stock Granted	290,131
Total Granted	1,644,968
Employee Awards [Member] | 2011 Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock Options Granted	166,810
Restricted Stock Granted	87,913
Total Granted	254,723
Non-Employee Director Awards [Member] | 1994 Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock Options Granted	153,654
Total Granted	153,654
Non-Employee Director Awards [Member] | 2000 Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock Options Granted	163,760
Restricted Stock Granted	2,700
Total Granted	166,460
Non-Employee Director Awards [Member] | 2003 Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock Options Granted	217,723
Restricted Stock Granted	28,935
Total Granted	246,658
Non-Employee Director Awards [Member] | 2008 Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock Options Granted	134,146
Restricted Stock Granted	36,313
Total Granted	170,459
Non-Employee Director Awards [Member] | 2011 Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Restricted Stock Granted	9,464
Total Granted	9,464