XML 42 R31.htm IDEA: XBRL DOCUMENT v3.5.0.2
Cash Equivalents and Marketable Securities - Additional Information (Details) - US government and agency securities
$ in Millions
Jun. 30, 2016
Security
Dec. 31, 2015
USD ($)
Security
Cash Equivalents And Marketable Securities [Line Items]    
Number of securities in an unrealized loss position for less than one year 0 5
Fair value of debt securities in an unrealized loss position | $   $ 2.5
Number of securities in a significant unrealized loss position   0