Investments (Schedule Of Debt Securities By Contractual Maturity Date) (Details) (USD $) In Thousands, unless otherwise specified	Mar. 31, 2013	Dec. 31, 2012
Investments [Abstract]
Due within 1 year	$ 52,632	$ 46,681
Due within more than 1 year but less than 5 years	15,798	17,209
Due within more than 5 years but less than 10 years	0	0
Due 10 years or after	320	2,633
Total	$ 68,750	$ 66,523

Amount of debt securities categorized neither as held-to-maturity nor trading.

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