Cash, Cash Equivalents And Short-Term Investments (Contractual Maturities Of Short-Term Investments Designated As Available-For-Sale) (Details) $ in Thousands	Sep. 30, 2015 USD ($)
Schedule of Available-for-sale Securities [Line Items]
Adjusted Cost, Due in less than 1 year	$ 103,808
Fair Value, Due in less than 1 year	103,885
Adjusted Cost, Due in 1 to 5 years	87,339
Fair Value, Due in 1 to 5 years	78,175
Adjusted Cost, Total	191,147
Fair Value, Total	182,060
Corporate Bonds [Member]
Schedule of Available-for-sale Securities [Line Items]
Adjusted Cost, Due in less than 1 year	36,381
Fair Value, Due in less than 1 year	36,397
Adjusted Cost, Due in 1 to 5 years	82,552
Fair Value, Due in 1 to 5 years	73,366
U.S. Treasuries And Agencies [Member]
Schedule of Available-for-sale Securities [Line Items]
Adjusted Cost, Due in less than 1 year	64,515
Fair Value, Due in less than 1 year	64,576
Adjusted Cost, Due in 1 to 5 years	4,787
Fair Value, Due in 1 to 5 years	4,809
Time Deposits [Member]
Schedule of Available-for-sale Securities [Line Items]
Adjusted Cost, Due in less than 1 year	2,912
Fair Value, Due in less than 1 year	$ 2,912