Quarterly report pursuant to Section 13 or 15(d)

Cash, Cash Equivalents and Short-Term Investments (Unrealized Loss Position) (Details)

v3.4.0.3
Cash, Cash Equivalents and Short-Term Investments (Unrealized Loss Position) (Details)
$ in Thousands
 3 Months Ended
Mar. 31, 2016
USD ($)
item
Fair value and gross unrealized losses of investments in individual securities in unrealized loss position  
Weighted-average time to maturity of cash equivalents and available-for-sale securities 128 days
Number of investments in continuous unrealized loss position for more than twelve months | item 0
Number of individual securities in unrealized loss position for twelve months or less | item 16
Other-than-temporary impairments of securities $ 0
Fair Value 24,403
Unrealized Losses (5)
U S Government-Sponsored Enterprises Securities  
Fair value and gross unrealized losses of investments in individual securities in unrealized loss position  
Fair Value 15,146
Unrealized Losses (4)
Corporate Bonds And Commercial Paper  
Fair value and gross unrealized losses of investments in individual securities in unrealized loss position  
Fair Value 9,257
Unrealized Losses $ (1)