Organization And Summary Of Significant Accounting Policies (Fair Value Measurements) (Details) (USD $)	Dec. 31, 2011	Dec. 31, 2010
Organization And Summary Of Significant Accounting Policies [Line Items]
Cash equivalents		$ 1,000,000
Total marketable securities, available for sale	79,358,000	42,224,000
Restricted Cash and Cash Equivalents	939,000	1,714,000
Level 1 [Member]
Organization And Summary Of Significant Accounting Policies [Line Items]
Cash equivalents		0
Total marketable securities, available for sale	0	0
Restricted Cash and Cash Equivalents	939,000	1,714,000
Level 2 [Member]
Organization And Summary Of Significant Accounting Policies [Line Items]
Cash equivalents		1,000,000
Total marketable securities, available for sale	79,358,000	42,224,000
Restricted Cash and Cash Equivalents	0	0
Level 3 [Member]
Organization And Summary Of Significant Accounting Policies [Line Items]
Cash equivalents		0
Restricted Cash and Cash Equivalents	0	0
U.S. Government Agencies [Member]
Organization And Summary Of Significant Accounting Policies [Line Items]
Marketable securities, available for sale	61,896,000	32,222,000
U.S. Government Agencies [Member] \| Level 1 [Member]
Organization And Summary Of Significant Accounting Policies [Line Items]
Marketable securities, available for sale	0	0
U.S. Government Agencies [Member] \| Level 2 [Member]
Organization And Summary Of Significant Accounting Policies [Line Items]
Marketable securities, available for sale	61,896,000	32,222,000
U.S. Government Agencies [Member] \| Level 3 [Member]
Organization And Summary Of Significant Accounting Policies [Line Items]
Marketable securities, available for sale	0	0
Commercial Paper [Member]
Organization And Summary Of Significant Accounting Policies [Line Items]
Marketable securities, available for sale	7,497,000	4,996,000
Commercial Paper [Member] \| Level 1 [Member]
Organization And Summary Of Significant Accounting Policies [Line Items]
Marketable securities, available for sale	0	0
Commercial Paper [Member] \| Level 2 [Member]
Organization And Summary Of Significant Accounting Policies [Line Items]
Marketable securities, available for sale	7,497,000	4,996,000
Commercial Paper [Member] \| Level 3 [Member]
Organization And Summary Of Significant Accounting Policies [Line Items]
Marketable securities, available for sale	0	0
Corporate Debt [Member]
Organization And Summary Of Significant Accounting Policies [Line Items]
Marketable securities, available for sale	9,965,000	5,006,000
Corporate Debt [Member] \| Level 1 [Member]
Organization And Summary Of Significant Accounting Policies [Line Items]
Marketable securities, available for sale	0	0
Corporate Debt [Member] \| Level 2 [Member]
Organization And Summary Of Significant Accounting Policies [Line Items]
Marketable securities, available for sale	9,965,000	5,006,000
Corporate Debt [Member] \| Level 3 [Member]
Organization And Summary Of Significant Accounting Policies [Line Items]
Marketable securities, available for sale	$ 0	$ 0

For an unclassified balance sheet, this item represents investments in debt and equity securities which are categorized neither as held-to-maturity nor trading.

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 320

-SubTopic 10

-Section 45

-Paragraph 1

-URI http://asc.fasb.org/extlink&oid=6871852&loc=d3e26610-111562

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 115

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-Subparagraph b

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 3: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name FASB Staff Position (FSP)

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-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 4: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

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-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 5: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name FASB Staff Position (FSP)

-Number FAS115-1/124-1

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-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 6: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 115

-Paragraph 13

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 7: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

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-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 8: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 115

-Paragraph 14

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 9: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 115

-Paragraph 16

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 10: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

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-Section 25

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-URI http://asc.fasb.org/extlink&oid=6379932&loc=d3e22054-111558

+ Details

- Definition

Cash equivalents, excluding items classified as marketable securities, include short-term, highly liquid investments that are both readily convertible to known amounts of cash, and so near their maturity that they present insignificant risk of changes in value because of changes in interest rates. Generally, only investments with original maturities of three months or less qualify under that definition. Original maturity means original maturity to the entity holding the investment. For example, both a three-month US Treasury bill and a three-year Treasury note purchased three months from maturity qualify as cash equivalents. However, a Treasury note purchased three years ago does not become a cash equivalent when its remaining maturity is three months. Compensating balance arrangements that do not legally restrict the withdrawal or usage of cash equivalents may be reported as cash equivalents, while legally restricted equivalents held as compensating balances against borrowing arrangements, contracts entered into with others, or company statements of intention with regard to particular equivalents are not generally reported as part of unrestricted cash equivalents.

+ References+ Details

- Definition

Total debt and equity financial instruments including: (1) securities held-to-maturity, (2) trading securities, and (3) securities available-for-sale.

+ References+ Details

- Definition

The carrying amounts of cash and cash equivalent items which are restricted as to withdrawal or usage. Restrictions may include legally restricted deposits held as compensating balances against borrowing arrangements, contracts entered into with others, or entity statements of intention with regard to particular deposits; however, time deposits and short-term certificates of deposit are not generally included in legally restricted deposits. Excludes compensating balance arrangements that are not agreements which legally restrict the use of cash amounts shown on the balance sheet. This element is for unclassified presentations; for classified presentations there is a separate and distinct element.

+ References+ Details