Annual report pursuant to Section 13 and 15(d)

Stock Option and Purchase Plans - Summary of Weighted-Average Assumptions (Detail)

v3.7.0.1
Stock Option and Purchase Plans - Summary of Weighted-Average Assumptions (Detail)
12 Months Ended
Dec. 31, 2016
Dec. 31, 2015
Dec. 31, 2014
Share-based Compensation Arrangement by Share-based Payment Award      
Dividend Yield 0.00% 0.00% 0.00%
Minimum      
Share-based Compensation Arrangement by Share-based Payment Award      
Risk-free Interest Rate 1.08% 1.36% 0.12%
Volatility Factor 0.40% 0.40% 0.42%
Expected Life in Years 4 years 4 years 4 years
Maximum      
Share-based Compensation Arrangement by Share-based Payment Award      
Risk-free Interest Rate 2.34% 2.10% 2.30%
Volatility Factor 0.45% 0.51% 0.52%
Expected Life in Years 8 years 8 years 8 years