|
Cash, Cash Equivalents, and Marketable Securities (Details 1) (USD $)
In Thousands, unless otherwise specified |
Jun. 30, 2012
|
Dec. 31, 2011
|
|---|---|---|
| Summary of amortized cost and estimated fair value of available for sale marketable securities | ||
| Fair Value | $ 92,433 | $ 62,562 |
|
Marketable Securities [Member]
|
||
| Summary of amortized cost and estimated fair value of available for sale marketable securities | ||
| Cost | 83,744 | 51,674 |
| Fair Value | $ 83,742 | $ 51,703 |