[Line Items] for Schedule of Shareholders' Equity [Table]

No definition available.

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- Definition

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

+ References

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-Publisher FASB
-Name Accounting Standards Codification
-Topic 505
-SubTopic 10
-Section S99
-Paragraph 1
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- Definition

Amount of cash outflow in the form of ordinary dividends to common shareholders of the parent entity.

+ References

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- Definition

Amount of stock repurchase plan authorized.

+ References

No definition available.

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- Definition

The number of shares authorized to be repurchased by an entity's Board of Directors under a stock repurchase plan.

+ References

No definition available.

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- Definition

Total cost of shares repurchased divided by the total number of shares repurchased.

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-Publisher FASB
-Name Accounting Standards Codification
-Topic 505
-SubTopic 30
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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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-Publisher FASB
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Shareholders' Equity (Details) - USD ($)							12 Months Ended			115 Months Ended	158 Months Ended	174 Months Ended
Shareholders' Equity (Details) - USD ($)	Nov. 10, 2020	May 15, 2020	Nov. 06, 2019	May 20, 2019	Nov. 08, 2018	May 18, 2018	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2019	Dec. 31, 2019	Dec. 31, 2019	Mar. 13, 2020	Mar. 05, 2019	May 16, 2018	May 19, 2015
Schedule of Shareholders' Equity [Line Items]
Authorized Repurchase													$ 20,000,000	$ 20,000,000	$ 15,000,000
Stock repurchased during period (in shares)							565,882	454,430	783,776			14,117,116
Aggregate price of shares repurchased since inception							$ 31,229,000	$ 20,793,000	$ 27,943,000			$ 240,544,000
Average price of shares repurchased since inception (per share)							$ 55.19	$ 45.76	$ 35.65			$ 17.04
Dividends declared (in dollars per share)							$ 0.38	$ 0.32	$ 0.32
Cash dividends paid							$ 19,800,000	$ 16,600,000	$ 16,700,000
Regular Semi-Annual Dividend
Schedule of Shareholders' Equity [Line Items]
Dividends declared (in dollars per share)	$ 0.19	$ 0.19	$ 0.16	$ 0.16	$ 0.16	$ 0.16
Open market
Schedule of Shareholders' Equity [Line Items]
Stock repurchase program amount authorized (in shares)																5,700,000
Stock repurchased during period (in shares)							103,689	5,799	252,272	4,205,255
Aggregate price of shares repurchased since inception							$ 4,987,000	$ 200,000	$ 8,374,000	$ 74,793,000
Average price of shares repurchased since inception (per share)							$ 48.10	$ 34.46	$ 33.19	$ 17.79
401(k)
Schedule of Shareholders' Equity [Line Items]
Stock repurchased during period (in shares)							438,921	419,963	497,753			7,906,660
Aggregate price of shares repurchased since inception							$ 25,073,000	$ 19,386,000	$ 18,472,000			$ 145,000,000
Average price of shares repurchased since inception (per share)							$ 57.12	$ 46.16	$ 37.11			$ 18.34
Directors & employees
Schedule of Shareholders' Equity [Line Items]
Stock repurchased during period (in shares)							23,272	28,668	33,751		2,005,201
Aggregate price of shares repurchased since inception							$ 1,169,000	$ 1,207,000	$ 1,097,000		$ 20,751,000
Average price of shares repurchased since inception (per share)							$ 50.23	$ 42.11	$ 32.49		$ 10.35