Quarterly report pursuant to Section 13 or 15(d)

Cash, Cash Equivalents And Short-Term And Long-Term Investments - Additional Information (Detail)

v3.10.0.1
Cash, Cash Equivalents And Short-Term And Long-Term Investments - Additional Information (Detail)
9 Months Ended
Sep. 30, 2018
Maximum [Member]  
Cash Cash Equivalents Short Term And Long Term Investments [Line Items]  
Long-term investments maturity period 2 years