Stock-Based Compensation Plans - Changes in Company's Common Stock Price During Reporting Period (Detail) - Stock Based Compensation Expense [Member] - $ / shares |
3 Months Ended | 9 Months Ended | ||
|---|---|---|---|---|
Sep. 30, 2017 |
Sep. 30, 2016 |
Sep. 30, 2017 |
Sep. 30, 2016 |
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| Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | ||||
| Common stock price at beginning of period | $ 26.36 | $ 25.41 | $ 26.72 | $ 29.14 |
| Common stock price at end of period | 26.99 | 26.15 | 26.99 | 26.15 |
| Increase (decrease) in stock price | $ 0.63 | $ 0.74 | $ 0.27 | $ (2.99) |
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- Definition Increase decrease in common stock price. No definition available.
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- Definition Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table. No definition available.
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- Definition Price of a single share of a number of saleable stocks of a company. No definition available.
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- Details
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