Marketable Securities (Schedule Of Marketable Securities) (Details) (USD $) In Thousands, unless otherwise specified	Jun. 30, 2013	Dec. 31, 2012
Marketable Securities [Line Items]
Cost	$ 16,249	$ 21,496
Available-for-sale Securities, Gross Unrealized Gains	0	1
Gross Unrealized Losses	(13)	(1)
Fair Value	16,236	21,496
Certificates Of Deposit
Marketable Securities [Line Items]
Cost	8,750	6,500
Available-for-sale Securities, Gross Unrealized Gains	0	0
Gross Unrealized Losses	(13)	(1)
Fair Value	8,737	6,499
Treasury Bills
Marketable Securities [Line Items]
Cost	7,499	14,996
Available-for-sale Securities, Gross Unrealized Gains	0	1
Gross Unrealized Losses	0	0
Fair Value	$ 7,499	$ 14,997

Amount of investment in debt and equity securities categorized neither as held-to-maturity nor trading.

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-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009.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.

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+ Details

- Definition

This item represents the cost of debt and equity securities, which are categorized neither as held-to-maturity nor trading, net of adjustments including accretion, amortization, collection of cash, previous other-than-temporary impairments recognized in earnings (less any cumulative-effect adjustments recognized, as defined), and fair value hedge accounting adjustments, if any.

+ References+ Details

- Definition

This item represents the gross unrealized gains for securities, at a point in time, which are categorized neither as held-to-maturity nor trading securities.

+ References+ Details