Represents the number of shares vesting during the period as a percentage of target.

No definition available.

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- Definition

Unrecognized cost of unvested share-based compensation awards.

+ References

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- References

No definition available.

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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

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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

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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

+ Details

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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).

+ References

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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

+ Details

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- Definition

A roll forward is a reconciliation of a concept from the beginning of a period to the end of a period.

+ References

No definition available.

+ Details

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- Definition

The weighted average fair value of nonvested awards on equity-based plans excluding option plans (for example, phantom stock or unit plan, stock or unit appreciation rights plan, revenue or profit achievement stock award plan) for which the employer is contingently obligated to issue equity instruments or transfer assets to an employee who has not yet satisfied service or performance criteria necessary to gain title to proceeds from the sale of the award or underlying shares or units.

+ References

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- Definition

A roll forward is a reconciliation of a concept from the beginning of a period to the end of a period.

+ References

No definition available.

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- Definition

The number of equity-based payment instruments, excluding stock (or unit) options, that vested during the reporting period.

+ References

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- References

No definition available.

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- Definition

The estimated measure of the percentage by which a share price is expected to fluctuate during a period. Volatility also may be defined as a probability-weighted measure of the dispersion of returns about the mean. The volatility of a share price is the standard deviation of the continuously compounded rates of return on the share over a specified period. That is the same as the standard deviation of the differences in the natural logarithms of the stock prices plus dividends, if any, over the period.

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- Definition

The risk-free interest rate assumption that is used in valuing an option on its own shares.

+ References

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- Definition

Price of a single share of a number of saleable stocks of a company.

+ References

No definition available.

+ Details

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- Definition

Expected term of share-based compensation awards, 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 (f)(2)(i)
-URI http://asc.fasb.org/extlink&oid=96867065&loc=d3e5070-113901

Reference 2: 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.D.2)
-URI http://asc.fasb.org/extlink&oid=27013229&loc=d3e301413-122809

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Share-Based Compensation - Restricted Stock Awards (Details) - USD ($)		6 Months Ended
	Mar. 08, 2018	Jun. 30, 2018	Jun. 30, 2017	Dec. 31, 2017
Restricted Stock
Restricted Stock Awards
Non-vested at beginning of period (in shares)		10,806	2,400
Granted (in shares)		10,019	9,604
Vested (in shares)		3,201
Non-vested at end of period (in shares)		17,624	12,004
Weighted Average Grant Date Fair Value
Non-vested at beginning of period (in dollars per share)		$ 29.16	$ 26.23
Granted (in dollars per share)		30.73	29.53
Non-vested at end of period (in dollars per share)		$ 29.92	$ 28.87
Unrecognized compensation
Vesting period		3 years
Unrecognized compensation costs		$ 460,000
Restricted Stock Units Based on a Performance Condition
Restricted Stock Awards
Non-vested at beginning of period (in shares)		11,520
Granted (in shares)		12,018
Non-vested at end of period (in shares)		23,538
Weighted Average Grant Date Fair Value
Non-vested at beginning of period (in dollars per share)		$ 29.53
Granted (in dollars per share)		30.73
Non-vested at end of period (in dollars per share)		$ 30.14
Unrecognized compensation
Unrecognized compensation costs		$ 253,000
Unrecognized compensation costs, period of recognition		3 years
Restricted Stock Units Based on a Performance Condition \| Minimum
Unrecognized compensation
Shares vesting as a percentage of target		0.00%
Restricted Stock Units Based on a Performance Condition \| Maximum
Unrecognized compensation
Shares vesting as a percentage of target		150.00%
Restricted Stock Units Based on a Market Condition
Restricted Stock Awards
Non-vested at beginning of period (in shares)		2,879
Granted (in shares)		3,005
Non-vested at end of period (in shares)		5,884
Weighted Average Grant Date Fair Value
Non-vested at beginning of period (in dollars per share)		$ 24.44
Granted (in dollars per share)		28.32
Non-vested at end of period (in dollars per share)		$ 26.42
Unrecognized compensation
Unrecognized compensation costs		$ 80,000
Unrecognized compensation costs, period of recognition		3 years
Assumptions used in the Monte Carlo valuation of PRSUs
Term used for risk-free rate and historical volatility	2 years 9 months 26 days
Risk-free interest rate (as a percent)	2.39%
Closing stock price (in dollars per share)	$ 30.73			$ 30.87
Annualized volatility (as a percent)	16.60%