XML 105 R57.htm IDEA: XBRL DOCUMENT v3.10.0.1
Stock-Based Compensation (Detail) - (Table 3) - $ / shares
12 Months Ended
Dec. 31, 2018
Dec. 31, 2017
Dec. 31, 2016
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]      
Dividend yield 0.00% 0.00% 0.00%
Weighted average fair value $ 6.75 $ 5.94 $ 4.74
Minimum [Member]      
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]      
Volatility 25.00% 23.00% 22.00%
Risk free interest rate 2.10% 1.50% 0.90%
Expected life in years 3 years 3 years 3 years
Maximum [Member]      
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]      
Volatility 33.00% 26.00% 26.00%
Risk free interest rate 2.90% 2.00% 1.90%
Expected life in years 5 years 5 years 5 years