Stock Plans (Reservation of Shares for Issuance) (Details)	Dec. 31, 2012
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Reservation of shares for issuance upon exercise, vesting or release of share-based compensation awards	1,945,243
Omnibus Equity Incentive Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Reservation of shares for issuance upon exercise, vesting or release of share-based compensation awards	1,686,687
Employee Stock Purchase Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Reservation of shares for issuance upon exercise, vesting or release of share-based compensation awards	96,800
1999 Director Stock Option Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Reservation of shares for issuance upon exercise, vesting or release of share-based compensation awards	3,000
1995 Stock Option Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Reservation of shares for issuance upon exercise, vesting or release of share-based compensation awards	158,756