Bonus compensation shares issued.

No definition available.

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- Definition

Share based compensation arrangement by share based payment award payout rate.

+ References

No definition available.

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- Definition

The remaining amount authorized by an entity's Board of Directors for stock repurchase or debt repayment.

+ References

No definition available.

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- Definition

Accumulated other comprehensive loss related to portion of other than temporary impairment (OTTI) due to factors other than credit losses on debt securities categorized as available-for-sale that an entity does not intend to sell and which it is not more likely than not that the entity will be required to sell before recovery of the amortized cost basis of the debt security. The amount represented by this item is net of tax, as applicable.

+ References

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- Definition

Aggregate dividends declared during the period for each share of common stock outstanding.

+ References

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- Definition

The maximum number of common shares permitted to be issued by an entity's charter and bylaws.

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-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
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-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02(29))
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- Definition

Amount of paid and unpaid common stock dividends declared with the form of settlement in cash.

+ References

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- Definition

Percentage of domestic federal statutory tax rate applicable to pretax income (loss).

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-Name Accounting Standards Codification
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- Definition

Amount after tax and reclassification adjustments, of (increase) decrease in accumulated other comprehensive (income) loss related to pension and other postretirement defined benefit plans.

+ References

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-Publisher FASB
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-SubTopic 10
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- Definition

The maximum number of nonredeemable preferred shares (or preferred stock redeemable solely at the option of the issuer) permitted to be issued by an entity's charter and bylaws.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
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-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02(28))
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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.

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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.

+ References

No definition available.

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- Definition

Number of share instruments newly issued under a share-based compensation plan.

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- Definition

Number of shares that have been repurchased during the period and are being held in treasury.

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- Definition

Equity impact of the cost of common and preferred stock that were repurchased during the period. Recorded using the cost method.

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Shareholders' Equity (Narrative) (Details) - USD ($) $ / shares in Units, $ in Thousands	1 Months Ended	3 Months Ended				6 Months Ended		12 Months Ended
	Feb. 28, 2017	Jun. 30, 2017	Mar. 31, 2017	Jun. 30, 2016	Mar. 31, 2016	Jun. 30, 2017	Jun. 30, 2016	Dec. 31, 2014	Dec. 31, 2016
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Authorized common stock (in shares)		100,000,000				100,000,000			100,000,000
Authorized preferred stock (in shares)		50,000,000				50,000,000			50,000,000
Quarterly dividend declared, per share (USD per share)		$ 0.310	$ 0.31	$ 0.31	$ 0.31	$ 0.62	$ 0.62
Dividend declared						$ 33,000	$ 32,900
Total authorizations which remain available for use		$ 109,600				$ 109,600
Common shares acquired (in shares)						0	44,500
Cost of common shares reacquired						$ 0	$ 2,106
Bonus compensation shares issued (in shares)	9,000
Gain (loss) related to unrecognized changes in defined benefit plan liabilities							$ 500
Non-credit loss, net of tax		$ 500				$ 500			$ 300
Statutory income tax rate		35.00%		35.00%		35.00%	35.00%
Restricted Share Units [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Awards in period (in shares)	84,600
Fair value of each unit awarded (USD per share)	$ 58.35
Award vesting period	3 years
Shares issued in period for share-based compensation (in shares)	29,300
Performance Shares [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Awards in period (in shares)	48,000
Shares issued in period for share-based compensation (in shares)	99,500
Performance Shares [Member] \| Minimum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Award payout rate	50.00%
Performance Shares [Member] \| Maximum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Award payout rate	200.00%
Performance Shares Granted in 2014 [Member] \| Minimum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Award payout rate								117.00%
Performance Shares Granted in 2014 [Member] \| Maximum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Award payout rate								125.00%