Investments (Number of Securities Included in Loss Position of Current and Noncurrent Investments) (Details)	Jun. 30, 2015 Securities
Current [Member]
Schedule of Available-for-sale Securities [Line Items]
Less than 12 Months	903
12 Months or More	70
Total, number of securities	973
Current [Member] | Asset-Backed Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Less than 12 Months	193
12 Months or More	32
Total, number of securities	225
Current [Member] | U.S. Government and Agencies [Member]
Schedule of Available-for-sale Securities [Line Items]
Less than 12 Months	2
12 Months or More	0
Total, number of securities	2
Current [Member] | Obligations of States and Other Political Subdivisions [Member]
Schedule of Available-for-sale Securities [Line Items]
Less than 12 Months	344
12 Months or More	13
Total, number of securities	357
Current [Member] | Corporate Debt Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Less than 12 Months	364
12 Months or More	25
Total, number of securities	389
Noncurrent [Member]
Schedule of Available-for-sale Securities [Line Items]
Less than 12 Months	8
12 Months or More	3
Total, number of securities	11
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	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	8
12 Months or More	1
Total, number of securities	9