Financial Instruments and Fair Value Measurements (Carrying Amounts and Fair Value) (Details) (USD $) | 6 Months Ended | 12 Months Ended | | |
In Thousands, unless otherwise specified | Jun. 30, 2014 | Dec. 31, 2013 | Mar. 31, 2013 | Dec. 31, 2012 |
Schedule of Available-for-sale Securities [Line Items] | ' | ' | ' | ' |
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than Twelve Months, Fair Value | $30,580 | $44,644 | ' | ' |
Cash | 15,949 | 14,092 | ' | ' |
Money market funds | 18,052 | 16,431 | ' | ' |
Cash and Cash Equivalents, at Carrying Value | 34,001 | 33,462 | 41,726 | 44,114 |
Available-for-sale Securities, Amortized Cost Basis | 108,376 | 102,644 | ' | ' |
Available-For-Sale Securities, Accumulated Gross Unrealized Gain, Before Tax | 103 | 38 | ' | ' |
Available-For-Sale Securities, Accumulated Gross Unrealized Loss, Before Tax | -65 | -72 | ' | ' |
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than 12 Months, Aggregate Loss | -65 | -72 | ' | ' |
Available-for-sale Securities, Continuous Unrealized Loss Position, Twelve Months or Longer, Fair Value | 0 | 0 | ' | ' |
Available-for-sale Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Aggregate Loss | 0 | 0 | ' | ' |
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value | 30,580 | 44,644 | ' | ' |
Available-for-sale Securities, Continuous Unrealized Loss Position, Aggregate Loss | 65 | 72 | ' | ' |
Available-for-sale Securities | 108,414 | 102,610 | ' | ' |
Municipal Bonds [Member] | ' | ' | ' | ' |
Schedule of Available-for-sale Securities [Line Items] | ' | ' | ' | ' |
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than Twelve Months, Fair Value | ' | 552 | ' | ' |
Available-for-sale Securities, Amortized Cost Basis | 5,323 | 3,827 | ' | ' |
Available-For-Sale Securities, Accumulated Gross Unrealized Gain, Before Tax | 13 | 5 | ' | ' |
Available-For-Sale Securities, Accumulated Gross Unrealized Loss, Before Tax | 0 | -2 | ' | ' |
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than 12 Months, Aggregate Loss | ' | -2 | ' | ' |
Available-for-sale Securities, Continuous Unrealized Loss Position, Twelve Months or Longer, Fair Value | ' | 0 | ' | ' |
Available-for-sale Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Aggregate Loss | ' | 0 | ' | ' |
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value | ' | 552 | ' | ' |
Available-for-sale Securities, Continuous Unrealized Loss Position, Aggregate Loss | ' | 2 | ' | ' |
Available-for-sale Securities | 5,336 | 3,830 | ' | ' |
US Government and Government Agencies and Authorities [Member] | ' | ' | ' | ' |
Schedule of Available-for-sale Securities [Line Items] | ' | ' | ' | ' |
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than Twelve Months, Fair Value | 19,949 | 24,975 | ' | ' |
Available-for-sale Securities, Amortized Cost Basis | 65,483 | 57,102 | ' | ' |
Available-For-Sale Securities, Accumulated Gross Unrealized Gain, Before Tax | 44 | 15 | ' | ' |
Available-For-Sale Securities, Accumulated Gross Unrealized Loss, Before Tax | -46 | -31 | ' | ' |
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than 12 Months, Aggregate Loss | -46 | -31 | ' | ' |
Available-for-sale Securities, Continuous Unrealized Loss Position, Twelve Months or Longer, Fair Value | 0 | 0 | ' | ' |
Available-for-sale Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Aggregate Loss | 0 | 0 | ' | ' |
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value | 19,949 | 24,975 | ' | ' |
Available-for-sale Securities, Continuous Unrealized Loss Position, Aggregate Loss | 46 | 31 | ' | ' |
Available-for-sale Securities | 65,481 | 57,086 | ' | ' |
Certificates of Deposit [Member] | ' | ' | ' | ' |
Schedule of Available-for-sale Securities [Line Items] | ' | ' | ' | ' |
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than Twelve Months, Fair Value | 4,215 | 12,714 | ' | ' |
Available-for-sale Securities, Amortized Cost Basis | 14,515 | 14,945 | ' | ' |
Available-For-Sale Securities, Accumulated Gross Unrealized Gain, Before Tax | 16 | 1 | ' | ' |
Available-For-Sale Securities, Accumulated Gross Unrealized Loss, Before Tax | -10 | -26 | ' | ' |
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than 12 Months, Aggregate Loss | -10 | -26 | ' | ' |
Available-for-sale Securities, Continuous Unrealized Loss Position, Twelve Months or Longer, Fair Value | 0 | 0 | ' | ' |
Available-for-sale Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Aggregate Loss | 0 | 0 | ' | ' |
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value | 4,215 | 12,714 | ' | ' |
Available-for-sale Securities, Continuous Unrealized Loss Position, Aggregate Loss | 10 | 26 | ' | ' |
Available-for-sale Securities | 14,521 | 14,920 | ' | ' |
Corporate Note Securities [Member] | ' | ' | ' | ' |
Schedule of Available-for-sale Securities [Line Items] | ' | ' | ' | ' |
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than Twelve Months, Fair Value | 6,416 | 6,403 | ' | ' |
Available-for-sale Securities, Amortized Cost Basis | 23,055 | 26,770 | ' | ' |
Available-For-Sale Securities, Accumulated Gross Unrealized Gain, Before Tax | 30 | 17 | ' | ' |
Available-For-Sale Securities, Accumulated Gross Unrealized Loss, Before Tax | -9 | -13 | ' | ' |
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than 12 Months, Aggregate Loss | -9 | -13 | ' | ' |
Available-for-sale Securities, Continuous Unrealized Loss Position, Twelve Months or Longer, Fair Value | 0 | 0 | ' | ' |
Available-for-sale Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Aggregate Loss | 0 | 0 | ' | ' |
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value | 6,416 | 6,403 | ' | ' |
Available-for-sale Securities, Continuous Unrealized Loss Position, Aggregate Loss | 9 | 13 | ' | ' |
Available-for-sale Securities | 23,076 | 26,774 | ' | ' |
US Government Agencies Debt Securities [Member] | ' | ' | ' | ' |
Schedule of Available-for-sale Securities [Line Items] | ' | ' | ' | ' |
Available-for-sale Securities, Amortized Cost Basis | ' | 2,939 | ' | ' |
Available-for-sale Securities | ' | $2,939 | ' | ' |