Investments (Number of Securities Included in Loss Position of Current and Noncurrent Investments) (Details)	Mar. 31, 2014 Securities
Current [Member]
Schedule of Available-for-sale Securities [Line Items]
Less than 12 Months	425
12 Months or More	107
Total, number of securities	532
Current [Member] | Asset-Backed Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Less than 12 Months	81
12 Months or More	22
Total, number of securities	103
Current [Member] | Obligations of States and Other Political Subdivisions [Member]
Schedule of Available-for-sale Securities [Line Items]
Less than 12 Months	151
12 Months or More	70
Total, number of securities	221
Current [Member] | Corporate Debt Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Less than 12 Months	193
12 Months or More	15
Total, number of securities	208
Noncurrent [Member]
Schedule of Available-for-sale Securities [Line Items]
Less than 12 Months	1
12 Months or More	2
Total, number of securities	3
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] | Corporate Debt Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Less than 12 Months	1
12 Months or More	1
Total, number of securities	2