Stock Plans (Reservation of Shares for Issuance) (Details)	Dec. 31, 2018 shares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total reservation of shares under stock compensation plans	3,525,794
2013 Omnibus Equity Incentive Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total reservation of shares under stock compensation plans	3,067,729
2004 Employee Stock Purchase Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total reservation of shares under stock compensation plans	458,065