XML 45 R31.htm IDEA: XBRL DOCUMENT v3.5.0.2
Balance Sheet Components - Additional Information (Detail) - USD ($)
1 Months Ended 3 Months Ended 6 Months Ended
Jun. 30, 2016
Jun. 30, 2016
Jun. 30, 2015
Jun. 30, 2016
Jun. 30, 2015
Dec. 31, 2015
Dec. 31, 2014
Schedule of Available-for-sale Securities [Line Items]              
Cash and cash equivalents $ 190,411,000 $ 190,411,000 $ 236,536,000 $ 190,411,000 $ 236,536,000 $ 153,324,000 $ 165,455,000
Contractual maturities of available-for-sale investments 3 years            
Other-than-temporary impairment loss   0 $ 0 0 $ 0    
Foreign subsidiaries [Member]              
Schedule of Available-for-sale Securities [Line Items]              
Cash and cash equivalents $ 25,600,000 $ 25,600,000   $ 25,600,000