Quarterly report pursuant to Section 13 or 15(d)

Cash, Cash Equivalents and Investments - Narrative (Details)

v3.5.0.2
Cash, Cash Equivalents and Investments - Narrative (Details)
3 Months Ended 9 Months Ended
Sep. 30, 2016
USD ($)
security
Sep. 30, 2016
USD ($)
security
Sep. 30, 2015
USD ($)
Cash and Cash Equivalents [Abstract]      
Number of owned securities that were in an unrealized loss position | security 32 32  
Unrealized losses deemed to be other-than-temporary, recognized $ 0 $ 0  
Proceeds from sale of investments $ 3,000,000.0 $ 3,507,000 $ 41,317,000