|
Cash, Cash Equivalents and Available-For-Sale Securities (Details2) (USD $)
In Thousands, unless otherwise specified |
Sep. 30, 2014
|
Dec. 31, 2013
|
|---|---|---|
| Cash equivalents and available-for-sale securities | ||
| Amortized Cost | $ 148,142 | $ 202,674 |
| Gross Unrealized Gains | 42 | 64 |
| Gross Unrealized Losses | (26) | (17) |
|
Fair Value Measurements Recurring [Member] | Fair Value Inputs Level2 [Member]
|
||
| Cash equivalents and available-for-sale securities | ||
| Fair Value | 148,158 | 202,721 |
|
U S Treasury Securities [Member]
|
||
| Cash equivalents and available-for-sale securities | ||
| Amortized Cost | 2,027 | 2,083 |
| Gross Unrealized Gains | 2 | 2 |
| Fair Value | 2,029 | 2,085 |
|
U S Treasury Securities [Member] | Fair Value Measurements Recurring [Member] | Fair Value Inputs Level2 [Member]
|
||
| Cash equivalents and available-for-sale securities | ||
| Fair Value | 2,029 | 2,085 |
|
U S Government Sponsored Enterprises Debt Securities [Member]
|
||
| Cash equivalents and available-for-sale securities | ||
| Amortized Cost | 52,082 | 67,160 |
| Gross Unrealized Gains | 19 | 29 |
| Gross Unrealized Losses | (8) | (11) |
| Fair Value | 52,093 | 67,178 |
|
U S Government Sponsored Enterprises Debt Securities [Member] | Fair Value Measurements Recurring [Member] | Fair Value Inputs Level2 [Member]
|
||
| Cash equivalents and available-for-sale securities | ||
| Fair Value | 52,093 | 67,178 |
|
Corporate Bond Securities And Commercial Paper [Member]
|
||
| Cash equivalents and available-for-sale securities | ||
| Amortized Cost | 94,033 | 133,431 |
| Gross Unrealized Gains | 21 | 33 |
| Gross Unrealized Losses | (18) | (6) |
| Fair Value | 94,036 | 133,458 |
|
Corporate Bond Securities And Commercial Paper [Member] | Fair Value Measurements Recurring [Member] | Fair Value Inputs Level2 [Member]
|
||
| Cash equivalents and available-for-sale securities | ||
| Fair Value | $ 94,036 | $ 133,458 |