Stock-Based Compensation (Schedule Of Reserved Shares) (Details)	Mar. 31, 2017 shares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares reserved for issuance (in shares)	115,000,000
Stock purchase plans
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares reserved for issuance (in shares)	39,000,000
Stock award plans
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares reserved for issuance (in shares)	76,000,000