Investments (Schedule Of Debt Securities By Contractual Maturity Date) (Details) (USD $) In Thousands, unless otherwise specified	Mar. 31, 2015	Dec. 31, 2014
Investments [Abstract]
Due within 1 year	$ 49,378	$ 59,896
Due within more than 1 year but less than 5 years	61,386	60,178
Due within more than 5 years but less than 10 years	0	0
Due 10 years or after	332	330
Total	$ 111,096	$ 120,404