Reconciliation Between Effective Tax Rate and U.S. Statutory Rate (Parenthetical) (Detail) - $ / shares |
12 Months Ended | ||
|---|---|---|---|
Dec. 31, 2016 |
Dec. 31, 2015 |
Dec. 31, 2014 |
|
| Income Tax Disclosure [Abstract] | |||
| Basic and diluted earnings per share amounts of the benefit resulting from the "Approved Enterprise" and "Benefited Enterprise" status | $ 0.13 | $ 0.08 | $ 0.04 |