Investments (Number of Securities Included in Loss Position of Current and Noncurrent Investments) (Details)	Dec. 31, 2013 Securities
Current [Member]
Schedule of Available-for-sale Securities [Line Items]
Less than 12 Months	481
12 Months or More	58
Total number of securities	539
Current [Member] | Asset-backed securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Less than 12 Months	91
12 Months or More	14
Total number of securities	105
Current [Member] | U.S. government and agencies [Member]
Schedule of Available-for-sale Securities [Line Items]
Less than 12 Months	3
12 Months or More	0
Total number of securities	3
Current [Member] | Obligations of states and other political subdivisions [Member]
Schedule of Available-for-sale Securities [Line Items]
Less than 12 Months	189
12 Months or More	35
Total number of securities	224
Current [Member] | Corporate debt securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Less than 12 Months	198
12 Months or More	9
Total number of securities	207
Noncurrent [Member]
Schedule of Available-for-sale Securities [Line Items]
Less than 12 Months	15
12 Months or More	19
Total number of securities	34
Noncurrent [Member] | Asset-backed 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
Noncurrent [Member] | Obligations of states and other political subdivisions [Member]
Schedule of Available-for-sale Securities [Line Items]
Less than 12 Months	8
12 Months or More	14
Total number of securities	22
Noncurrent [Member] | Corporate debt securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Less than 12 Months	6
12 Months or More	4
Total number of securities	10