Quarterly report pursuant to Section 13 or 15(d)

Earnings Per Share - Additional Information (Detail)

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
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]        
Equity grants with anti-dilutive effect 3.3 3.9 3.6 4.8
Convertible Debt [Member]        
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]        
Convertible notes initial conversion price $ 86.28 $ 86.28 $ 86.28 $ 86.28