Investments (Number of Securities Included in Loss Position of Current and Noncurrent Investments) (Details)	Sep. 30, 2013 Securities
Current [Member]
Schedule of Available-for-sale Securities [Line Items]
Less than 12 Months	551
12 Months or More	11
Total, number of securities	562
Current [Member] | Asset-Backed Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Less than 12 Months	101
12 Months or More	7
Total, number of securities	108
Current [Member] | Obligations of States and Other Political Subdivisions [Member]
Schedule of Available-for-sale Securities [Line Items]
Less than 12 Months	237
12 Months or More	1
Total, number of securities	238
Current [Member] | Corporate Debt Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Less than 12 Months	213
12 Months or More	3
Total, number of securities	216
Noncurrent [Member]
Schedule of Available-for-sale Securities [Line Items]
Less than 12 Months	27
12 Months or More	1
Total, number of securities	28
Noncurrent [Member] | Asset-Backed Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Less than 12 Months	0
12 Months or More	1
Total, number of securities	1
Noncurrent [Member] | Obligations of States and Other Political Subdivisions [Member]
Schedule of Available-for-sale Securities [Line Items]
Less than 12 Months	18
12 Months or More	0
Total, number of securities	18
Noncurrent [Member] | Corporate Debt Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Less than 12 Months	9
12 Months or More	0
Total, number of securities	9