Investments (Financial Assets Measured At Fair Value) (Details) (USD $) | Dec. 31, 2013 | Dec. 31, 2012 |
In Thousands, unless otherwise specified |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | ' | ' |
Cash & cash equivalents, Total | $65,881 | ' |
Short-Term Investments [Member] | ' | ' |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | ' | ' |
Investments, Total | 32,162 | 32,162 |
Long-Term Investments [Member] | ' | ' |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | ' | ' |
Investments, Total | 9,787 | ' |
Fair Value, Inputs, Level 1 [Member] | ' | ' |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | ' | ' |
Cash & cash equivalents, Total | 65,881 | ' |
Fair Value, Inputs, Level 1 [Member] | Short-Term Investments [Member] | ' | ' |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | ' | ' |
Investments, Total | ' | ' |
Fair Value, Inputs, Level 1 [Member] | Long-Term Investments [Member] | ' | ' |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | ' | ' |
Investments, Total | ' | ' |
Fair Value, Inputs, Level 2 [Member] | ' | ' |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | ' | ' |
Cash & cash equivalents, Total | ' | ' |
Fair Value, Inputs, Level 2 [Member] | Short-Term Investments [Member] | ' | ' |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | ' | ' |
Investments, Total | 32,162 | 32,162 |
Fair Value, Inputs, Level 2 [Member] | Long-Term Investments [Member] | ' | ' |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | ' | ' |
Investments, Total | 9,787 | ' |
Fair Value, Inputs, Level 3 [Member] | ' | ' |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | ' | ' |
Cash & cash equivalents, Total | ' | ' |
Fair Value, Inputs, Level 3 [Member] | Short-Term Investments [Member] | ' | ' |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | ' | ' |
Investments, Total | ' | ' |
Fair Value, Inputs, Level 3 [Member] | Long-Term Investments [Member] | ' | ' |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | ' | ' |
Investments, Total | ' | ' |
Cash [Member] | ' | ' |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | ' | ' |
Cash & cash equivalents, Total | 57,715 | 8,166 |
Cash [Member] | Fair Value, Inputs, Level 1 [Member] | ' | ' |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | ' | ' |
Cash & cash equivalents, Total | 57,715 | 8,166 |
Cash [Member] | Fair Value, Inputs, Level 2 [Member] | ' | ' |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | ' | ' |
Cash & cash equivalents, Total | ' | ' |
Cash [Member] | Fair Value, Inputs, Level 3 [Member] | ' | ' |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | ' | ' |
Cash & cash equivalents, Total | ' | ' |
Money Market Funds [Member] | ' | ' |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | ' | ' |
Cash & cash equivalents, Total | 8,166 | 65,881 |
Money Market Funds [Member] | Fair Value, Inputs, Level 1 [Member] | ' | ' |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | ' | ' |
Cash & cash equivalents, Total | 8,166 | 65,881 |
Money Market Funds [Member] | Fair Value, Inputs, Level 2 [Member] | ' | ' |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | ' | ' |
Cash & cash equivalents, Total | ' | ' |
Money Market Funds [Member] | Fair Value, Inputs, Level 3 [Member] | ' | ' |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | ' | ' |
Cash & cash equivalents, Total | ' | ' |
Corporate Notes [Member] | Short-Term Investments [Member] | ' | ' |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | ' | ' |
Investments, Total | 28,307 | 28,307 |
Corporate Notes [Member] | Long-Term Investments [Member] | ' | ' |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | ' | ' |
Investments, Total | 9,787 | 9,787 |
Corporate Notes [Member] | Fair Value, Inputs, Level 1 [Member] | Short-Term Investments [Member] | ' | ' |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | ' | ' |
Investments, Total | ' | ' |
Corporate Notes [Member] | Fair Value, Inputs, Level 1 [Member] | Long-Term Investments [Member] | ' | ' |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | ' | ' |
Investments, Total | ' | ' |
Corporate Notes [Member] | Fair Value, Inputs, Level 2 [Member] | Short-Term Investments [Member] | ' | ' |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | ' | ' |
Investments, Total | 28,307 | 28,307 |
Corporate Notes [Member] | Fair Value, Inputs, Level 2 [Member] | Long-Term Investments [Member] | ' | ' |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | ' | ' |
Investments, Total | 9,787 | 9,787 |
Corporate Notes [Member] | Fair Value, Inputs, Level 3 [Member] | Short-Term Investments [Member] | ' | ' |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | ' | ' |
Investments, Total | ' | ' |
Corporate Notes [Member] | Fair Value, Inputs, Level 3 [Member] | Long-Term Investments [Member] | ' | ' |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | ' | ' |
Investments, Total | ' | ' |
Agency Bonds [Member] | Short-Term Investments [Member] | ' | ' |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | ' | ' |
Investments, Total | 1,008 | ' |
Agency Bonds [Member] | Long-Term Investments [Member] | ' | ' |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | ' | ' |
Investments, Total | ' | 9,787 |
Agency Bonds [Member] | Fair Value, Inputs, Level 1 [Member] | Short-Term Investments [Member] | ' | ' |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | ' | ' |
Investments, Total | ' | ' |
Agency Bonds [Member] | Fair Value, Inputs, Level 2 [Member] | Short-Term Investments [Member] | ' | ' |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | ' | ' |
Investments, Total | 1,008 | ' |
Agency Bonds [Member] | Fair Value, Inputs, Level 2 [Member] | Long-Term Investments [Member] | ' | ' |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | ' | ' |
Investments, Total | ' | 9,787 |
Agency Bonds [Member] | Fair Value, Inputs, Level 3 [Member] | Short-Term Investments [Member] | ' | ' |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | ' | ' |
Investments, Total | ' | ' |
Commercial Paper [Member] | Short-Term Investments [Member] | ' | ' |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | ' | ' |
Investments, Total | 2,297 | 2,297 |
Commercial Paper [Member] | Fair Value, Inputs, Level 1 [Member] | Short-Term Investments [Member] | ' | ' |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | ' | ' |
Investments, Total | ' | ' |
Commercial Paper [Member] | Fair Value, Inputs, Level 2 [Member] | Short-Term Investments [Member] | ' | ' |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | ' | ' |
Investments, Total | 2,297 | 2,297 |
Commercial Paper [Member] | Fair Value, Inputs, Level 3 [Member] | Short-Term Investments [Member] | ' | ' |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | ' | ' |
Investments, Total | ' | ' |
Certificates Of Deposit [Member] | Short-Term Investments [Member] | ' | ' |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | ' | ' |
Investments, Total | 550 | 550 |
Certificates Of Deposit [Member] | Fair Value, Inputs, Level 1 [Member] | Short-Term Investments [Member] | ' | ' |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | ' | ' |
Investments, Total | ' | ' |
Certificates Of Deposit [Member] | Fair Value, Inputs, Level 2 [Member] | Short-Term Investments [Member] | ' | ' |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | ' | ' |
Investments, Total | 550 | 550 |
Certificates Of Deposit [Member] | Fair Value, Inputs, Level 3 [Member] | Short-Term Investments [Member] | ' | ' |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | ' | ' |
Investments, Total | ' | ' |