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Note 3 - Securities (Details) (USD $) |  |  |  |  |  |  |  |  | 6 Months Ended |  |
--- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | ---
Jun. 30, 2014 | Dec. 31, 2013 | Jun. 30, 2014 Debt Securities [Member] | Jun. 30, 2014 Mutual Funds [Member] | Dec. 31, 2013 Mutual Funds [Member] | Jun. 30, 2014 State of Michigan and all its Political Subdivisions [Member] | Dec. 31, 2013 State of Michigan and all its Political Subdivisions [Member] | Jun. 30, 2014 US States and Political Subdivisions Debt Securities [Member] | Dec. 31, 2013 US States and Political Subdivisions Debt Securities [Member] | Jun. 30, 2014 Securities Other Than US Government Agencies and the State of Michigan and Political Subdivisions [Member] Stockholders' Equity, Total [Member] Securities Issued Concentration Risk [Member] | Jun. 30, 2014 US Government Agency Debt Obligations and Mortgage-Backed Securities [Member] | Dec. 31, 2013 US Government Agency Debt Obligations and Mortgage-Backed Securities [Member]
Note 3 - Securities (Details) [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |
Available-for-sale, Securities in Unrealized Loss Positions, Qualitative Disclosure, Number of Positions |  |  |  |  | 452 | 1 |  |  |  |  |  |  |  |
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value | $ 325,525,000 |  | $ 88,446,000 |  |  |  | $ 1,355,000 |  |  |  |  |  |  |
Available-for-sale Securities, Continuous Unrealized Loss Position, Accumulated Loss | 7,149,000 |  | 10,100,000 |  |  |  | 31,000 |  |  |  |  |  |  |
Available-for-sale Debt Securities, Amortized Cost Basis | 471,333,000 |  |  |  |  |  |  | 114,800,000 | 17,400,000 | 36,400,000 | 36,300,000 |  |  |
Available-for-sale Securities | 475,275,000 | [1] | 131,178,000 | [1] |  |  | 1,355,000 | 115,200,000 | 17,800,000 |  |  |  |  |
Concentration Risk, Percentage |  |  |  |  |  |  |  |  |  |  |  | 0.00% |  |
Available-for-sale Securities, Restricted |  |  |  |  |  |  |  |  |  |  |  |  | $ 272,600,000 | $ 94,400,000
[1] | See Note 13 for a description of the fair value hierarchy as well as a disclosure of levels for classes of financial assets and liabilities.

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- Definition This item represents the cost of debt securities, which are categorized neither as held-to-maturity nor trading, net of adjustments including accretion, amortization, collection of cash, previous other-than-temporary impairments recognized in earnings (less any cumulative-effect adjustments recognized, as defined), and fair value hedge accounting adjustments, if any. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02.2) -URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 320 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (aa) -URI http://asc.fasb.org/extlink&oid=27724398&loc=d3e27161-111563 + Details
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- Definition Amount of investment in debt and equity securities categorized neither as held-to-maturity nor trading. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 320 -SubTopic 10 -Section 25 -Paragraph 1 -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=28360136&loc=d3e22054-111558 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 320 -SubTopic 10 -Section 50 -Paragraph 5 -Subparagraph (aa) -URI http://asc.fasb.org/extlink&oid=27724398&loc=d3e27232-111563 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 320 -SubTopic 10 -Section 45 -Paragraph 1 -URI http://asc.fasb.org/extlink&oid=6871852&loc=d3e26610-111562 + Details
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- Definition Amount of accumulated unrealized loss on investments in debt and equity securities classified as available-for-sale in a continuous loss position. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 320 -SubTopic 10 -Section 50 -Paragraph 7 -URI http://asc.fasb.org/extlink&oid=27724398&loc=d3e27337-111563 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 320 -SubTopic 10 -Section 50 -Paragraph 6 -Subparagraph (a)(2) -URI http://asc.fasb.org/extlink&oid=27724398&loc=d3e27290-111563 + Details
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- Definition This item represents the aggregate fair value of investments in debt and equity securities in an unrealized loss position which are categorized neither as held-to-maturity nor trading securities. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 320 -SubTopic 10 -Section 50 -Paragraph 6 -Subparagraph (a)(1) -URI http://asc.fasb.org/extlink&oid=27724398&loc=d3e27290-111563 + Details
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- Definition The carrying amount of securities categorized neither as held-to-maturity nor trading which serve as security for borrowings or other arrangements. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 03 -Paragraph 6 -Article 9 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 08 -Paragraph b -Article 4 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 310 -SubTopic 10 -Section 50 -Paragraph 5 -URI http://asc.fasb.org/extlink&oid=35738203&loc=d3e5086-111524 Reference 4: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 235 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX210.4-08(b)) -URI http://asc.fasb.org/extlink&oid=26873400&loc=d3e23780-122690 + Details
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