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Stock-Based Compensation Plans - Summary of Transactions of the Company's Stock Option Plans (Detail) - Stock Options Plan [Member] | 12 Months Ended
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Dec. 31, 2016 $ / shares shares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] |
Outstanding, Number of Options, Beginning balance | shares | 667,439
Exercised, Number of Options | shares | (151,164)
Forfeited, Number of Options | shares | (37,621)
Outstanding, Number of Options, Ending balance | shares | 570,994
Outstanding, Weighted Average Exercise Price, Beginning balance | $ 19.87
Exercised, Weighted Average Exercise Price | 14.38
Forfeited, Weighted Average Exercise Price | 14.49
Outstanding, Weighted Average Exercise Price, Ending balance | 20.38
Outstanding, Weighted Average Grant-Date Fair Value | 20.19
Exercised | 19.63
Forfeited, Weighted Average Grant-Date Fair Value | 24.83
Outstanding, Weighted Average Grant-Date Fair Value | $ 21.68
Discount [Member] |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] |
Granted, Number of Options | shares | 67,546
Granted, Weighted Average Exercise Price | $ 0.00
Granted, Weighted Average Grant-Date Fair Value | $ 38.13
Market Value [Member] |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] |
Granted, Number of Options | shares | 24,794
Granted, Weighted Average Exercise Price | $ 44.34
Granted, Weighted Average Grant-Date Fair Value | $ 9.17

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- Definition The number of shares under options that were cancelled during the reporting period as a result of occurrence of a terminating event specified in contractual agreements pertaining to the stock option plan. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (c)(1)(iv)(3) -URI http://asc.fasb.org/extlink&oid=6415400&loc=d3e5070-113901 + Details
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- Definition Gross number of share options (or share units) granted during the period. + References No definition available. + Details
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- Definition The weighted average grant-date fair value of options granted during the reporting period as calculated by applying the disclosed option pricing methodology. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (d)(1) -URI http://asc.fasb.org/extlink&oid=6415400&loc=d3e5070-113901 + Details
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- Definition Number of options outstanding, including both vested and non-vested options. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section 50 -Paragraph 2 -URI http://asc.fasb.org/extlink&oid=6415400&loc=d3e5070-113901 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (c)(1)(i)-(ii) -URI http://asc.fasb.org/extlink&oid=6415400&loc=d3e5070-113901 + Details
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