v3.10.0.1
Earnings per Share - Computation of Earnings per Share (EPS) (Parenthetical) (Detail) - $ / shares
shares in Millions
12 Months Ended
Dec. 31, 2018
Dec. 31, 2017
Dec. 31, 2016
Common Stock [Member]      
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]      
Exercise price of warrants $ 132.55 $ 133.32 $ 133.32
Stock Options [Member] | Maximum [Member]      
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]      
Anti-dilutive securities excluded from computation of earning per share amount 0.1 0.1 1.4
Unvested RSU's, PSU's and Equity Rights [Member] | Maximum [Member]      
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]      
Anti-dilutive securities excluded from computation of earning per share amount 0.9 0.7 0.9
Warrant [Member] | Maximum [Member]      
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]      
Anti-dilutive securities excluded from computation of earning per share amount 11.2 11.2 11.2