Fair Value Measurements (Fair Value) (Details) - Fair Value, Measurements, Recurring - USD ($)
$ in Thousands |
Sep. 30, 2016 |
Dec. 31, 2015 |
| Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |
|
|
| Total assets |
$ 33,100
|
$ 42,221
|
| Quoted Prices in Active Markets for Identical Assets (Level 1) |
|
|
| Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |
|
|
| Total assets |
28,599
|
34,806
|
| Significant Other Observable Inputs (Level 2) |
|
|
| Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |
|
|
| Total assets |
4,501
|
7,415
|
| Significant Unobservable Inputs (Level 3) |
|
|
| Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |
|
|
| Total assets |
0
|
0
|
| Money market funds |
|
|
| Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |
|
|
| Total assets |
28,599
|
34,806
|
| Money market funds | Quoted Prices in Active Markets for Identical Assets (Level 1) |
|
|
| Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |
|
|
| Total assets |
28,599
|
34,806
|
| Money market funds | Significant Other Observable Inputs (Level 2) |
|
|
| Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |
|
|
| Total assets |
0
|
0
|
| Money market funds | Significant Unobservable Inputs (Level 3) |
|
|
| Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |
|
|
| Total assets |
0
|
0
|
| Commercial paper |
|
|
| Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |
|
|
| Total assets |
1,493
|
|
| Commercial paper | Quoted Prices in Active Markets for Identical Assets (Level 1) |
|
|
| Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |
|
|
| Total assets |
0
|
|
| Commercial paper | Significant Other Observable Inputs (Level 2) |
|
|
| Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |
|
|
| Total assets |
1,493
|
|
| Commercial paper | Significant Unobservable Inputs (Level 3) |
|
|
| Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |
|
|
| Total assets |
0
|
|
| Corporate debt securities |
|
|
| Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |
|
|
| Total assets |
3,008
|
7,415
|
| Corporate debt securities | Quoted Prices in Active Markets for Identical Assets (Level 1) |
|
|
| Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |
|
|
| Total assets |
0
|
0
|
| Corporate debt securities | Significant Other Observable Inputs (Level 2) |
|
|
| Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |
|
|
| Total assets |
3,008
|
7,415
|
| Corporate debt securities | Significant Unobservable Inputs (Level 3) |
|
|
| Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |
|
|
| Total assets |
$ 0
|
$ 0
|