Business Combination, Consideration Transferred, Acquiree's Common Shares Converted In Cash Per Share

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- Definition

Number of Equal Successive Installments for Vesting of Stock Awards

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- Definition

Number of shares reserved for issuance under equity instrument agreements awarded that validly exist and are outstanding, including vested instruments.

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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.

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- Definition

Unrecognized cost of unvested share-based compensation awards.

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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.

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- Definition

Amount of cash inflow from issuance of shares under share-based compensation arrangement. Issuance includes, but is not limited to, exercise of stock options and similar instruments.

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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).

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- Definition

The weighted average fair value at grant date for nonvested equity-based awards issued 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).

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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.

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- Definition

The highest percentage of annual salary that an employee is permitted to utilize with respect to the plan.

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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).

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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.

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- Definition

Percentage of vesting of share-based compensation awards.

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- Definition

Purchase price of common stock expressed as a percentage of its fair value.

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No definition available.

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- Definition

The noncash expense that accounts for the value of stock or unit options distributed to employees as compensation.

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Equity Plans (Details) $ / shares in Units, $ in Thousands			3 Months Ended
Equity Plans (Details) $ / shares in Units, $ in Thousands	Jan. 29, 2019 $ / shares shares	Jan. 02, 2019 vesting_installment $ / shares shares	Mar. 31, 2019 USD ($) shares	Mar. 31, 2018 USD ($)	Mar. 14, 2018 $ / shares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Compensation costs charged to income: \| $			$ 886	$ 487
Restricted stock and deferred restricted stock
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Compensation costs charged to income: \| $			$ 743	372
Recognition period for unrecognized compensation cost			1 year 6 months 18 days
Unrecognized compensation costs \| $			$ 4,306
Key officers \| Restricted Stock Units (RSUs)
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of equity instruments granted (shares) \| shares		17,451
Number of equal successive installments for vesting of stock awards (vesting installments) \| vesting_installment		3
Grant date fair value of equity instruments granted (usd per share) \| $ / shares		$ 51.28
Key officers \| Performance Shares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of equity instruments granted (shares) \| shares	9,882
Key officers \| Performance Shares \| Minimum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Target vesting percentage	0.00%
Key officers \| Performance Shares \| Maximum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Target vesting percentage	150.00%
Key officers \| Performance Shares 2
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of equity instruments granted (shares) \| shares	9,043
Grant date fair value of equity instruments granted (usd per share) \| $ / shares	$ 54.84
Key officers \| Performance Shares 2 \| Minimum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Target vesting percentage	0.00%
Key officers \| Performance Shares 2 \| Maximum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Target vesting percentage	150.00%
Key officers \| Performance Shares 3
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of equity instruments granted (shares) \| shares	9,437
Grant date fair value of equity instruments granted (usd per share) \| $ / shares	$ 70.47
Key officers \| Performance Shares 3 \| Minimum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Target vesting percentage	0.00%
Key officers \| Performance Shares 3 \| Maximum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Target vesting percentage	200.00%
Incentive Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Remaining shares available for issuance under the Incentive Plan (shares) \| shares			832,711
Shares issuable upon exercise of Incentive Plan awards (shares) \| shares			155,625
Employee Stock Purchase Plan (ESPP)
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Compensation costs charged to income: \| $			$ 143	115
ESPP proceeds \| $			$ 811	653
Purchase price of common stock under ESPP (percent)			85.00%
Maximum percentage of base compensation employees can designate for stock purchases under ESPP (percent)			10.00%
Plan expense \| $			$ 76	$ 53
Unrecognized compensation costs \| $			$ 116
Employee Stock Purchase Plan (ESPP) \| Common Stock
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of shares authorized for issuance under the plan (shares) \| shares			400,000
CTWS [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Business Combination, Consideration Transferred, Acquiree's Common Shares Converted In Cash Per Share \| $ / shares					$ 70.00
Share-based Compensation Award, Tranche One [Member] \| Key officers \| Performance Shares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Grant date fair value of equity instruments granted (usd per share) \| $ / shares	$ 57.12
Share-based Compensation Award, Tranche Two [Member] \| Key officers \| Performance Shares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Grant date fair value of equity instruments granted (usd per share) \| $ / shares	$ 55.97