|
Cash, Cash Equivalents, and Marketable Securities (Details Textual) (USD $)
|
3 Months Ended | |
|---|---|---|
|
Jun. 30, 2012
|
Dec. 31, 2011
|
|
| Cash, Cash Equivalents, and Marketable Securities (Textual) [Abstract] | ||
| Maturity of fair value of marketable securities | 1 year | |
| Fair Value of The Marketable Security having Maturity one Year or Less | $ 43,239,000 | $ 51,703,000 |
| Fair Value of The Marketable Security having Maturity one Year or Two year | 5,100,000 | |
|
Estimate of Fair Value, Fair Value Disclosure [Member]
|
||
| Cash, Cash Equivalents, and Marketable Securities (Textual) [Abstract] | ||
| Fair Value of The Marketable Security having Maturity one Year or Less | $ 78,700,000 | |
|
Minimum [Member]
|
||
| Cash, Cash Equivalents, and Marketable Securities (Textual) [Abstract] | ||
| Maturity of fair value of marketable securities | 1 year | |
|
Maximum [Member]
|
||
| Cash, Cash Equivalents, and Marketable Securities (Textual) [Abstract] | ||
| Maturity of fair value of marketable securities | 2 years |