v3.8.0.1

Stock-Based Compensation Plans - Additional Information (Detail) - USD ($) | 1 Months Ended | 12 Months Ended |
--- | --- | --- | ---
Dec. 31, 2017 | Sep. 30, 2017 | Sep. 30, 2016 | Sep. 30, 2015 | Sep. 30, 2014
Stock-Based Compensation Activity [Line Items] |  |  |  |  |
Unrecognized compensation costs related to non-vested awards |  | $ 4,700,000 |  |  |
Weighted average period for recognition of compensation costs related to non-vested awards |  | 2 years 1 month 7 days |  |  |
Performance share awards fully expensed |  | $ 1,500,000 |  |  |
Weighted average per share fair value of stock options |  | $ 7.63 | $ 6.95 | $ 7.26 |
Dividend rates |  | 0.00% | 0.00% | 0.00% |
Vesting period |  | 3 years | 3 years | 3 years |
Aggregate intrinsic value of the option shares outstanding |  | $ 10,000,000 |  |  |
Aggregate intrinsic value of the option shares exercisable |  | $ 6,100,000 |  |  |
Remaining contractual life of options outstanding |  | 4 years |  |  |
Remaining contractual life of options exercisable |  | 2 years 9 months 19 days |  |  |
Total pre-tax intrinsic value of options exercised |  | $ 100,000 | $ 5,100,000 |  |
Stock compensation expenses recognized |  | $ 3,472,000 | 3,844,000 | $ 2,381,000 |
Fiscal 2013 (2013 - 2015) [Member] |  |  |  |  |
Stock-Based Compensation Activity [Line Items] |  |  |  |  |
Performance period start year |  | 2013 |  |  |
Performance period end year |  | 2015 |  |  |
Fiscal 2014 (2014 - 2016) [Member] |  |  |  |  |
Stock-Based Compensation Activity [Line Items] |  |  |  |  |
Performance period start year |  | 2014 |  |  |
Performance period end year |  | 2016 |  |  |
Fiscal 2015 (2015 - 2017) [Member] |  |  |  |  |
Stock-Based Compensation Activity [Line Items] |  |  |  |  |
Performance period start year |  | 2015 |  |  |
Performance period end year |  | 2017 |  |  |
Fiscal 2015 (2015 - 2017) [Member] | Scenario Forecast [Member] |  |  |  |  |
Stock-Based Compensation Activity [Line Items] |  |  |  |  |
Maximum estimated shares earned | 51,483 |  |  |  |
Fiscal 2016 (2016 - 2018) [Member] |  |  |  |  |
Stock-Based Compensation Activity [Line Items] |  |  |  |  |
Performance period start year |  | 2016 |  |  |
Performance period end year |  | 2018 |  |  |
Maximum estimated shares earned |  | 57,979 |  |  |
Fiscal 2017 (2016 - 2018) [Member] |  |  |  |  |
Stock-Based Compensation Activity [Line Items] |  |  |  |  |
Performance period start year |  | 2016 |  |  |
Performance period end year |  | 2018 |  |  |
Fiscal 2017 (2017 - 2019) [Member] |  |  |  |  |
Stock-Based Compensation Activity [Line Items] |  |  |  |  |
Maximum estimated shares earned |  | 63,561 |  |  |
Nonqualified Stock Options [Member] |  |  |  |  |
Stock-Based Compensation Activity [Line Items] |  |  |  |  |
Stock compensation expenses recognized |  | $ 1,300,000 | 1,200,000 | 1,200,000 |
Nonqualified Stock Options [Member] | Employee [Member] |  |  |  |  |
Stock-Based Compensation Activity [Line Items] |  |  |  |  |
Vesting period |  | 4 years |  |  |
Nonqualified Stock Options [Member] | Minimum [Member] | Board of Director [Member] |  |  |  |  |
Stock-Based Compensation Activity [Line Items] |  |  |  |  |
Stock option expiration term upon expiration of employment or service |  | 7 years |  |  |
Nonqualified Stock Options [Member] | Maximum [Member] | Board of Director [Member] |  |  |  |  |
Stock-Based Compensation Activity [Line Items] |  |  |  |  |
Stock option expiration term upon expiration of employment or service |  | 10 years |  |  |
Restricted Stock Awards [Member] |  |  |  |  |
Stock-Based Compensation Activity [Line Items] |  |  |  |  |
Vesting period |  | 3 years |  |  |
Restricted stock expense |  | $ 500,000 | $ 300,000 | $ 300,000 |
Number of stock units awarded |  | 51,559 | 20,108 | 18,073 |
Number of stock units forfeited |  | 2,278 | 2,439 | 1,316 |
Number of stock units outstanding |  | 67,917 | 33,133 | 27,775 | 18,624
Performance Shares [Member] |  |  |  |  |
Stock-Based Compensation Activity [Line Items] |  |  |  |  |
Stock compensation expenses recognized |  | $ 1,200,000 | $ 1,900,000 | $ 500,000 |
Performance Shares [Member] | Fiscal 2015 (2015 - 2017) [Member] |  |  |  |  |
Stock-Based Compensation Activity [Line Items] |  |  |  |  |
Fair value of performance shares for grants awarded |  |  |  | 900,000 |
Performance Shares [Member] | Fiscal 2016 (2016 - 2018) [Member] |  |  |  |  |
Stock-Based Compensation Activity [Line Items] |  |  |  |  |
Fair value of performance shares for grants awarded |  |  | 1,300,000 |  |
Performance Shares [Member] | Fiscal 2017 (2016 - 2018) [Member] |  |  |  |  |
Stock-Based Compensation Activity [Line Items] |  |  |  |  |
Fair value of performance shares for grants awarded |  | 1,200,000 |  |  |
1999 Employee Stock Purchase Plan [Member] |  |  |  |  |
Stock-Based Compensation Activity [Line Items] |  |  |  |  |
Annual compensation withheld, maximum limit |  | $ 25,000 |  |  |
1999 Employee Stock Purchase Plan [Member] | Maximum [Member] |  |  |  |  |
Stock-Based Compensation Activity [Line Items] |  |  |  |  |
Common stock authorized, shares |  | 600,000 |  |  |
Stock compensation expenses recognized |  | $ 100,000 | 100,000 | 100,000 |
Annual compensation withheld |  | 10.00% |  |  |
Employee contributions |  | $ 100,000 | 100,000 |  |
Vesting Anniversary [Member] | Nonqualified Stock Options [Member] | Employee [Member] |  |  |  |  |
Stock-Based Compensation Activity [Line Items] |  |  |  |  |
Vesting percentage |  | 25.00% |  |  |
Vesting Anniversary [Member] | Restricted Stock Awards [Member] |  |  |  |  |
Stock-Based Compensation Activity [Line Items] |  |  |  |  |
Vesting percentage |  | 33.00% |  |  |
Performance Level [Member] | Minimum [Member] |  |  |  |  |
Stock-Based Compensation Activity [Line Items] |  |  |  |  |
Vesting percentage |  | 20.00% |  |  |
Performance Level [Member] | Maximum [Member] |  |  |  |  |
Stock-Based Compensation Activity [Line Items] |  |  |  |  |
Performance share awards, estimated vesting percentage |  | 200.00% |  |  |
2009 Equity Incentive Plan [Member] |  |  |  |  |
Stock-Based Compensation Activity [Line Items] |  |  |  |  |
Common stock authorized, shares |  | 2,000,000 |  |  |
Number of shares available for future awards |  | 888,546 |  |  |
2009 Equity Incentive Plan [Member] | Restricted Stock Units (RSUs) [Member] |  |  |  |  |
Stock-Based Compensation Activity [Line Items] |  |  |  |  |
Stock compensation expenses recognized |  | $ 300,000 | $ 200,000 | 400,000 |
Number of stock units awarded |  | 16,004 | 18,877 |  |
Number of stock units forfeited |  | 495 | 1,609 |  |
Number of stock units outstanding |  | 44,391 | 32,101 |  |
2009 Equity Incentive Plan [Member] | Deferred Stock Units [Member] | Director [Member] |  |  |  |  |
Stock-Based Compensation Activity [Line Items] |  |  |  |  |
Stock compensation expenses recognized |  | $ 100,000 | $ 200,000 | $ 100,000 |
Number of stock units outstanding |  | 24,441 | 21,077 |  |
Number of stock units outstanding estimated fair value |  | $ 800,000 |  |  |

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- Definition Represents the expense recognized during the period arising from equity-based compensation arrangements (for example, shares of stock, unit, stock options or other equity instruments) with employees, directors and certain consultants qualifying for treatment as employees. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SAB Topic 14.F) -URI http://asc.fasb.org/extlink&oid=27013229&loc=d3e301413-122809 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section 50 -Paragraph 1 -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=96867065&loc=d3e5047-113901 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (h)(1)(i) -URI http://asc.fasb.org/extlink&oid=96867065&loc=d3e5070-113901 + Details
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- Definition Unrecognized cost of unvested share-based compensation awards. + 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 (i) -URI http://asc.fasb.org/extlink&oid=96867065&loc=d3e5070-113901 + Details
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- Definition Weighted average period over which unrecognized compensation is expected to be recognized for equity-based compensation plans, 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 (i) -URI http://asc.fasb.org/extlink&oid=96867065&loc=d3e5070-113901 + Details
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- Definition Period which an employee's right to exercise an award is no longer contingent on satisfaction of either a service condition, market condition or a performance condition, 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)(1) -URI http://asc.fasb.org/extlink&oid=96867065&loc=d3e5070-113901 + Details
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- Definition The number of equity-based payment instruments, excluding stock (or unit) options, that were forfeited during the reporting period. + 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=96867065&loc=d3e5070-113901 + Details
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- Definition The number of grants made during the period on other than stock (or unit) option plans (for example, phantom stock or unit plan, stock or unit appreciation rights plan, performance target 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)(2)(iii)(1) -URI http://asc.fasb.org/extlink&oid=96867065&loc=d3e5070-113901 + Details
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- Definition The number of non-vested equity-based payment instruments, excluding stock (or unit) options, that validly exist and are outstanding as of the balance sheet date. + 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)(2)(i)-(ii) -URI http://asc.fasb.org/extlink&oid=96867065&loc=d3e5070-113901 + Details
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- Definition Fair value of share-based awards for which the grantee gained the right by satisfying service and performance requirements, to receive or retain shares or units, other instruments, or cash. + 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)(2) -URI http://asc.fasb.org/extlink&oid=96867065&loc=d3e5070-113901 + Details
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- Definition The estimated dividend rate (a percentage of the share price) to be paid (expected dividends) to holders of the underlying shares over the option's term. + 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 (f)(2)(iii) -URI http://asc.fasb.org/extlink&oid=96867065&loc=d3e5070-113901 + Details
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- Definition The maximum number of shares (or other type of equity) originally approved (usually by shareholders and board of directors), net of any subsequent amendments and adjustments, for awards under the equity-based compensation plan. As stock or unit options and equity instruments other than options are awarded to participants, the shares or units remain authorized and become reserved for issuance under outstanding awards (not necessarily vested). + 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)(3) -URI http://asc.fasb.org/extlink&oid=96867065&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=96867065&loc=d3e5070-113901 + Details
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- Definition Amount of accumulated difference between fair value of underlying shares on dates of exercise and exercise price on options exercised (or share units converted) into shares. + 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)(2) -URI http://asc.fasb.org/extlink&oid=96867065&loc=d3e5070-113901 + 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=96867065&loc=d3e5070-113901 + Details
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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=96867065&loc=d3e5070-113901 + Details
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