Fair Value Measurements (Details) (USD $)
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Sep. 30, 2012
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Dec. 31, 2011
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Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] |
|
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Available-for-sale Securities |
$ 90,000
|
$ 127,000
|
Carrying (Reported) Amount, Fair Value Disclosure [Member]
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|
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Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] |
|
|
Cash and Cash Equivalents, Fair Value Disclosure |
60,529,000
|
|
Marketable Securities, Fair Value Disclosure |
4,904,000
|
|
Estimate of Fair Value, Fair Value Disclosure [Member]
|
|
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Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] |
|
|
Cash and Cash Equivalents, Fair Value Disclosure |
60,529,000
|
|
Marketable Securities, Fair Value Disclosure |
4,904,000
|
|
Fair Value, Inputs, Level 1 [Member]
|
|
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Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] |
|
|
Cash and Cash Equivalents, Fair Value Disclosure |
60,529,000
|
|
Marketable Securities, Fair Value Disclosure |
4,904,000
|
|
Money Market Funds [Member] | Carrying (Reported) Amount, Fair Value Disclosure [Member]
|
|
|
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] |
|
|
Marketable Securities, Fair Value Disclosure |
48,000
|
|
Money Market Funds [Member] | Estimate of Fair Value, Fair Value Disclosure [Member]
|
|
|
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] |
|
|
Marketable Securities, Fair Value Disclosure |
48,000
|
|
Money Market Funds [Member] | Fair Value, Inputs, Level 1 [Member]
|
|
|
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] |
|
|
Marketable Securities, Fair Value Disclosure |
48,000
|
|
Mutual Funds [Member] | Carrying (Reported) Amount, Fair Value Disclosure [Member]
|
|
|
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] |
|
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Marketable Securities, Fair Value Disclosure |
42,000
|
|
Mutual Funds [Member] | Estimate of Fair Value, Fair Value Disclosure [Member]
|
|
|
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] |
|
|
Marketable Securities, Fair Value Disclosure |
42,000
|
|
Mutual Funds [Member] | Fair Value, Inputs, Level 1 [Member]
|
|
|
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] |
|
|
Marketable Securities, Fair Value Disclosure |
42,000
|
|
US Treasury Securities [Member] | Carrying (Reported) Amount, Fair Value Disclosure [Member]
|
|
|
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] |
|
|
Marketable Securities, Fair Value Disclosure |
3,537,000
|
|
US Treasury Securities [Member] | Estimate of Fair Value, Fair Value Disclosure [Member]
|
|
|
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] |
|
|
Marketable Securities, Fair Value Disclosure |
3,537,000
|
|
US Treasury Securities [Member] | Fair Value, Inputs, Level 1 [Member]
|
|
|
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] |
|
|
Marketable Securities, Fair Value Disclosure |
3,537,000
|
|
US Government Agencies Securities [Member] | Carrying (Reported) Amount, Fair Value Disclosure [Member]
|
|
|
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] |
|
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Marketable Securities, Fair Value Disclosure |
1,277,000
|
|
US Government Agencies Securities [Member] | Estimate of Fair Value, Fair Value Disclosure [Member]
|
|
|
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] |
|
|
Marketable Securities, Fair Value Disclosure |
1,277,000
|
|
US Government Agencies Securities [Member] | Fair Value, Inputs, Level 1 [Member]
|
|
|
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] |
|
|
Marketable Securities, Fair Value Disclosure |
1,277,000
|
|
Cash [Member] | Carrying (Reported) Amount, Fair Value Disclosure [Member]
|
|
|
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] |
|
|
Cash and Cash Equivalents, Fair Value Disclosure |
18,698,000
|
|
Cash [Member] | Estimate of Fair Value, Fair Value Disclosure [Member]
|
|
|
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] |
|
|
Cash and Cash Equivalents, Fair Value Disclosure |
18,698,000
|
|
Cash [Member] | Fair Value, Inputs, Level 1 [Member]
|
|
|
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] |
|
|
Cash and Cash Equivalents, Fair Value Disclosure |
18,698,000
|
|
Money Market Funds [Member] | Carrying (Reported) Amount, Fair Value Disclosure [Member]
|
|
|
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] |
|
|
Cash and Cash Equivalents, Fair Value Disclosure |
41,831,000
|
|
Money Market Funds [Member] | Estimate of Fair Value, Fair Value Disclosure [Member]
|
|
|
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] |
|
|
Cash and Cash Equivalents, Fair Value Disclosure |
41,831,000
|
|
Money Market Funds [Member] | Fair Value, Inputs, Level 1 [Member]
|
|
|
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] |
|
|
Cash and Cash Equivalents, Fair Value Disclosure |
$ 41,831,000
|
|