Note 14 - Commitments and Off-balance Sheet Risk - Exposure to Credit Losses (Details) - USD ($)	Dec. 31, 2016	Dec. 31, 2015
Contractual amounts of financial instruments with off-balance sheet risk	$ 821,338,000	$ 821,738,000
Standby Letters of Credit [Member]
Contractual amounts of financial instruments with off-balance sheet risk	26,202,000	34,946,000
Unused lines of Credit [Member] | Commercial Portfolio Segment [Member]
Contractual amounts of financial instruments with off-balance sheet risk	553,345,000	522,658,000
Unused lines of Credit [Member] | One to Four Family Mortgages [Member]
Contractual amounts of financial instruments with off-balance sheet risk	56,275,000	61,905,000
Unused lines of Credit [Member] | Consumer Portfolio Segment [Member]
Contractual amounts of financial instruments with off-balance sheet risk	22,689,000	15,612,000
Unused lines of Credit [Member] | Consumer Other Financing Receivable 1 [Member]
Contractual amounts of financial instruments with off-balance sheet risk	8,489,000	8,583,000
Loan Origination Commitments [Member]
Contractual amounts of financial instruments with off-balance sheet risk	$ 154,338,000	$ 178,034,000