Fair Value Measurements and Investment Securities (Details) - USD ($) $ in Thousands | Sep. 30, 2015 | Dec. 31, 2014 |
Fair Value Inputs, Assets, Quantitative Information [Line Items] | | |
Total Investment Securities | $ 70,762 | |
Fair Value, Measurements, Recurring [Member] | | |
Fair Value Inputs, Assets, Quantitative Information [Line Items] | | |
Total Cash Equivalents | 83,895 | $ 43,587 |
Total Investment Securities | 70,762 | |
Fair Value, Measurements, Recurring [Member] | US Treasury and U.S. or state government agency-backed securities [Member] | | |
Fair Value Inputs, Assets, Quantitative Information [Line Items] | | |
Total Investment Securities | 13,834 | |
Fair Value, Measurements, Recurring [Member] | Corporate Debt Securities [Member] | | |
Fair Value Inputs, Assets, Quantitative Information [Line Items] | | |
Total Investment Securities | 50,701 | |
Fair Value, Measurements, Recurring [Member] | Municipal Bonds [Member] | | |
Fair Value Inputs, Assets, Quantitative Information [Line Items] | | |
Total Investment Securities | 6,227 | |
Fair Value, Measurements, Recurring [Member] | Money Market Funds [Member] | | |
Fair Value Inputs, Assets, Quantitative Information [Line Items] | | |
Total Cash Equivalents | 65,211 | 43,587 |
Fair Value, Measurements, Recurring [Member] | US Government Corporations and Agencies Securities [Member] | | |
Fair Value Inputs, Assets, Quantitative Information [Line Items] | | |
Total Cash Equivalents | 16,059 | |
Fair Value, Measurements, Recurring [Member] | Commercial Paper [Member] | | |
Fair Value Inputs, Assets, Quantitative Information [Line Items] | | |
Total Cash Equivalents | 2,625 | |
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 1 [Member] | | |
Fair Value Inputs, Assets, Quantitative Information [Line Items] | | |
Total Cash Equivalents | 65,211 | 43,587 |
Total Investment Securities | 0 | |
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 1 [Member] | US Treasury and U.S. or state government agency-backed securities [Member] | | |
Fair Value Inputs, Assets, Quantitative Information [Line Items] | | |
Total Investment Securities | 0 | |
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 1 [Member] | Corporate Debt Securities [Member] | | |
Fair Value Inputs, Assets, Quantitative Information [Line Items] | | |
Total Investment Securities | 0 | |
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 1 [Member] | Municipal Bonds [Member] | | |
Fair Value Inputs, Assets, Quantitative Information [Line Items] | | |
Total Investment Securities | 0 | |
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 1 [Member] | Money Market Funds [Member] | | |
Fair Value Inputs, Assets, Quantitative Information [Line Items] | | |
Total Cash Equivalents | 65,211 | 43,587 |
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 1 [Member] | US Government Corporations and Agencies Securities [Member] | | |
Fair Value Inputs, Assets, Quantitative Information [Line Items] | | |
Total Cash Equivalents | 0 | |
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 1 [Member] | Commercial Paper [Member] | | |
Fair Value Inputs, Assets, Quantitative Information [Line Items] | | |
Total Cash Equivalents | 0 | |
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 2 [Member] | | |
Fair Value Inputs, Assets, Quantitative Information [Line Items] | | |
Total Cash Equivalents | 18,684 | 0 |
Total Investment Securities | 70,762 | |
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 2 [Member] | US Treasury and U.S. or state government agency-backed securities [Member] | | |
Fair Value Inputs, Assets, Quantitative Information [Line Items] | | |
Total Investment Securities | 13,834 | |
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 2 [Member] | Corporate Debt Securities [Member] | | |
Fair Value Inputs, Assets, Quantitative Information [Line Items] | | |
Total Investment Securities | 50,701 | |
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 2 [Member] | Municipal Bonds [Member] | | |
Fair Value Inputs, Assets, Quantitative Information [Line Items] | | |
Total Investment Securities | 6,227 | |
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 2 [Member] | Money Market Funds [Member] | | |
Fair Value Inputs, Assets, Quantitative Information [Line Items] | | |
Total Cash Equivalents | 0 | 0 |
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 2 [Member] | US Government Corporations and Agencies Securities [Member] | | |
Fair Value Inputs, Assets, Quantitative Information [Line Items] | | |
Total Cash Equivalents | 16,059 | |
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 2 [Member] | Commercial Paper [Member] | | |
Fair Value Inputs, Assets, Quantitative Information [Line Items] | | |
Total Cash Equivalents | 2,625 | |
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 3 [Member] | | |
Fair Value Inputs, Assets, Quantitative Information [Line Items] | | |
Total Cash Equivalents | 0 | 0 |
Total Investment Securities | 0 | |
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 3 [Member] | US Treasury and U.S. or state government agency-backed securities [Member] | | |
Fair Value Inputs, Assets, Quantitative Information [Line Items] | | |
Total Investment Securities | 0 | |
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 3 [Member] | Corporate Debt Securities [Member] | | |
Fair Value Inputs, Assets, Quantitative Information [Line Items] | | |
Total Investment Securities | 0 | |
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 3 [Member] | Municipal Bonds [Member] | | |
Fair Value Inputs, Assets, Quantitative Information [Line Items] | | |
Total Investment Securities | 0 | |
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 3 [Member] | Money Market Funds [Member] | | |
Fair Value Inputs, Assets, Quantitative Information [Line Items] | | |
Total Cash Equivalents | 0 | $ 0 |
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 3 [Member] | US Government Corporations and Agencies Securities [Member] | | |
Fair Value Inputs, Assets, Quantitative Information [Line Items] | | |
Total Cash Equivalents | 0 | |
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 3 [Member] | Commercial Paper [Member] | | |
Fair Value Inputs, Assets, Quantitative Information [Line Items] | | |
Total Cash Equivalents | $ 0 | |