XML 65 R53.htm IDEA: XBRL DOCUMENT v3.8.0.1
Earnings Per Share - Additional information (Detail) - shares
shares in Millions
3 Months Ended 9 Months Ended
Sep. 30, 2017
Sep. 30, 2016
Sep. 30, 2017
Sep. 30, 2016
Earnings Per Share [Abstract]        
Options to purchase common stock shares outstanding 1.7 4.5 1.2 5.8