Shareholders' Equity (Schedule Of Shares Reserved For Future Issuance) (Details)	Sep. 28, 2019 shares
Share-based Compensation Arrangement by Share-based Payment Award
Class A shares and Class B shares reserved for issuance	12,451,721
Conversion Of Class B To Class A Shares
Share-based Compensation Arrangement by Share-based Payment Award
Class A shares and Class B shares reserved for issuance	7,484,778
Employee Stock Purchase Plan
Share-based Compensation Arrangement by Share-based Payment Award
Class A shares and Class B shares reserved for issuance	1,866,485
2014 Long Term Incentive Plan
Share-based Compensation Arrangement by Share-based Payment Award
Class A shares and Class B shares reserved for issuance	1,902,393
2008 Stock Appreciation Rights Plan
Share-based Compensation Arrangement by Share-based Payment Award
Class A shares and Class B shares reserved for issuance	1,198,065