The aggregate depreciation from amortized cost basis as a percent.

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- Definition

Number of issuers of debt securities.

+ References

No definition available.

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- Definition

Number of securities.

+ References

No definition available.

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- Definition

Represents the number of states investments are held in.

+ References

No definition available.

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- Definition

Number of investment positions in available-for-sale investments in a continuous unrealized loss position for which an other-than-temporary impairment (OTTI) has not been recognized in the income statement.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 320
-SubTopic 10
-Section 50
-Paragraph 6
-Subparagraph (b)(3)
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- Definition

Number of investment positions in available-for-sale investments that have been in a continuous unrealized loss position for greater than or equal to a year for which an other-than-temporary impairment (OTTI) has not been recognized in the income statement.

+ References

No definition available.

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- Definition

For an entity that discloses a concentration risk in relation to quantitative amount, which serves as the "benchmark" (or denominator) in the equation, this concept represents the concentration percentage derived from the division.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
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- Definition

The amount by which the fair value of an investment is less than the amortized cost basis or carrying amount of that investment at the balance sheet date and the decline in fair value is deemed to be other than temporary, before considering whether or not such amount is recognized in earnings or other comprehensive income.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 320
-SubTopic 10
-Section 45
-Paragraph 8A
-URI http://asc.fasb.org/extlink&oid=109979856&loc=SL6284422-111562

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- Definition

Fair value portion of investment securities, including, but not limited to, marketable securities, derivative financial instruments, and investments accounted for under the equity method.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
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-SubTopic 10
-Section 50
-Paragraph 2
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Note 2 - Investment Securities (Details) $ in Thousands	3 Months Ended		6 Months Ended		12 Months Ended
Note 2 - Investment Securities (Details) $ in Thousands	Jun. 30, 2018 USD ($) state item	Jun. 30, 2017 USD ($)	Jun. 30, 2018 USD ($) state item	Jun. 30, 2017 USD ($)	Dec. 31, 2017 USD ($) state item
Number of securities \| item	602		602
Available-for-sale, unrealized loss positions, qualitative disclosure, number of positions \| item	303		303
Aggregate losses of securities (as a percent)	2.40%		2.40%
Available-for-sale, unrealized loss positions, qualitative disclosure, number of positions, greater than or equal to one year \| item	42		42
Other than temporary impairment losses, investments	$ 0	$ 0	$ 0	$ 0
General Obligation Bonds \| Stockholders' Equity, Total [Member] \| Credit Concentration Risk [Member]
Concentration risk percentage (as a percent)			0.00%		0.00%
Revenue Bonds \| Stockholders' Equity, Total [Member] \| Credit Concentration Risk [Member]
Concentration risk percentage (as a percent)			0.00%		0.00%
Municipal Bonds \| General Obligation Bonds
Number of issuers \| item	122		122		131
Other investments	$ 94,800		$ 94,800		$ 108,000
Number of states holding investments \| state	26		26		26
Municipal Bonds \| General Obligation Bonds \| Minimum
Other investments	$ 5,000		$ 5,000		$ 5,000
Municipal Bonds \| General Obligation Bonds \| Aggregate Fair Value Exceeding 5 Million [Member]
Number of states holding investments \| state	6		6		6
Municipal Bonds \| Revenue Bonds
Number of issuers \| item	150		150		145
Other investments	$ 360,900		$ 360,900		$ 337,300
Number of states holding investments	16		16		16
Municipal Bonds \| Revenue Bonds \| Minimum
Other investments					$ 5,000
Municipal Bonds \| Revenue Bonds \| Aggregate Fair Value Exceeding 5 Million [Member]
Other investments	$ 5,000		$ 5,000
Number of states holding investments	7		7		7