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Stock Options (Details) (USD $) | 3 Months Ended | 9 Months Ended |
--- | --- | --- | ---
Sep. 30, 2014 | Sep. 30, 2013 | Sep. 30, 2014 | Sep. 30, 2013 | Apr. 05, 2012
Employee Stock Option [Member] |  |  |  |  |
Stock option details |  |  |  |  |
Maximum exercisable period for options granted |  |  | 10 years |  |
Shares available for future grants | 211,500 |  | 211,500 |  | 800,000
Stock option activity |  |  |  |  |
Options outstanding at the beginning of the period (in shares) |  |  | 515,143 |  |
Plus: Options granted (in shares) |  |  | 549,750 |  |
Less: |  |  |  |  |
Options exercised (in shares) |  |  | 30,392 |  |
Options expired (in shares) |  |  | 11,825 |  |
Options forfeited (in shares) |  |  | 19,775 |  |
Options outstanding at the end of the period (in shares) | 1,002,901 |  | 1,002,901 |  |
Options fully vested and exercisable at the end of the period (in shares) | 230,006 |  | 230,006 |  |
Stock options, weighted average exercise price |  |  |  |  |
Options outstanding at the beginning, weighted average exercise price (in dollars per share) |  |  | $ 15.98 |  |
Plus: Options granted, weighted average exercise price (in dollars per share) |  |  | $ 21.42 |  |
Less: |  |  |  |  |
Options exercised, weighted average exercise price (in dollars per share) |  |  | $ 13.36 |  |
Options expired, weighted average exercise price (in dollars per share) |  |  | $ 26.70 |  |
Options forfeited, weighted average exercise price (in dollars per share) |  |  | $ 18.60 |  |
Options outstanding at the end, weighted average exercise price (in dollars per share) | $ 18.86 |  | $ 18.86 |  |
Options fully vested and exercisable at the end, weighted average exercise price (in dollars per share) | $ 17.08 |  | $ 17.08 |  |
Stock options, weighted average remaining contractual term |  |  |  |  |
Options outstanding at the end, weighted average remaining contractual term |  |  | 6 years 9 months 7 days |  |
Options fully vested and exercisable at the end, weighted average remaining contractual term |  |  | 2 years 1 month 6 days |  |
Stock options, aggregate intrinsic value |  |  |  |  |
Options outstanding at the end, aggregate intrinsic value | $ 7,011,000 |  | $ 7,011,000 |  |
Options fully vested and exercisable at the end, aggregate intrinsic value | 2,057,000 |  | 2,057,000 |  |
Stock-based compensation expense | 301,000 | 101,000 | 766,000 | 322,000 |
Stock-based compensation cost, unrecognized, related to non-vested options | $ 4,226,000 |  | $ 4,226,000 |  |
Stock-based compensation cost, unrecognized, related to non-vested options, weighted-average period of recognition |  |  | 2 years 4 months 24 days |  |
Incentive Stock Options to 10 Percent Shareholders [Member] |  |  |  |  |
Stock option details |  |  |  |  |
Maximum exercisable period for options granted |  |  | 5 years |  |

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- Definition Period from grant date that an equity-based award expires, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days. + 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 (a)(2) -URI http://asc.fasb.org/extlink&oid=6415400&loc=d3e5070-113901 + Details
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- Definition The difference between the maximum number of shares (or other type of equity) authorized for issuance under the plan (including the effects of amendments and adjustments), and the sum of: 1) the number of shares (or other type of equity) already issued upon exercise of options or other equity-based awards under the plan; and 2) shares (or other type of equity) reserved for issuance on granting of outstanding awards, net of cancellations and forfeitures, if applicable. + 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 + Details
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- Definition Amount of difference between fair value of the underlying shares reserved for issuance and exercise price of vested portions of options outstanding and currently exercisable. + 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 + Details
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- Definition The number of shares into which fully or partially vested stock options outstanding as of the balance sheet date can be currently converted under the 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)(iii) -URI http://asc.fasb.org/extlink&oid=6415400&loc=d3e5070-113901 + Details
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- Definition The weighted-average price as of the balance sheet date at which grantees can acquire the shares reserved for issuance on vested portions of options outstanding and currently exercisable under 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)(iii) -URI http://asc.fasb.org/extlink&oid=6415400&loc=d3e5070-113901 + Details
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- Definition Weighted average remaining contractual term for vested portions of options outstanding and currently exercisable or convertible, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days. + 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 + Details
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- Definition Number of options or other stock instruments for which the right to exercise has lapsed under the terms of the plan agreements. + 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)(4) -URI http://asc.fasb.org/extlink&oid=6415400&loc=d3e5070-113901 + Details
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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 Amount by which the current fair value of the underlying stock exceeds the exercise price of options outstanding. + 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 + 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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- Definition Weighted average remaining contractual term for option awards outstanding, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days. + 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 (e)(1) -URI http://asc.fasb.org/extlink&oid=6415400&loc=d3e5070-113901 + Details
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