Note 18 - Stockholders' Equity - Accumulated Other Comprehensive Income (Details) - USD ($)			3 Months Ended
		Jan. 01, 2018	Mar. 31, 2018	Mar. 31, 2017
Beginning balance, loss, net of tax		$ 1,973,304,000	$ 1,973,304,000
Reclassification adjustment for stranded tax effects of Tax Cuts and Job Act, tax		515,000
Ending balance, loss, net of tax			2,009,792,000
Accumulated Net Investment Gain (Loss) Attributable to Parent [Member]
Beginning balance, loss, net of tax		(1,060,000)	(1,060,000)	$ (1,545,000)
Reclassification adjustment for stranded tax effects of Tax Cuts and Job Act, tax	[1]		200,000
Reclassification adjustment for stranded tax effects of Tax Cuts and Job Act, net of tax	[1]		(200,000)
Net unrealized (losses)/gains arising during the period, pre-tax			(16,346,000)	(856,000)
Net unrealized (losses)/gains arising during the period, tax			(4,832,000)	(360,000)
Net unrealized (losses)/gains arising during the period, net of tax			(11,514,000)	(496,000)
Reclassification adjustment for net losses/(gains) included in net income, pre-tax				466,000
Reclassification adjustment for net losses/(gains) included in net income, tax				196,000
Reclassification adjustment for net losses/(gains) included in net income, net of tax				270,000
Total other comprehensive (loss)/income, pre-tax			(16,346,000)	(390,000)
Total other comprehensive (loss)/income, tax			(4,832,000)	(164,000)
Total other comprehensive (loss)/income, net of tax			(11,514,000)	(226,000)
Ending balance, loss, net of tax			(21,333,000)	(1,771,000)
Accumulated Gain (Loss), Net, Cash Flow Hedge, Parent [Member]
Beginning balance, loss, net of tax		(1,451,000)	(1,451,000)	(2,170,000)
Reclassification adjustment for stranded tax effects of Tax Cuts and Job Act, tax	[1]		315,000
Reclassification adjustment for stranded tax effects of Tax Cuts and Job Act, net of tax	[1]		(315,000)
Net unrealized (losses)/gains arising during the period, pre-tax			3,113,000	516,000
Net unrealized (losses)/gains arising during the period, tax			920,000	217,000
Net unrealized (losses)/gains arising during the period, net of tax			2,193,000	299,000
Reclassification adjustment for net losses/(gains) included in net income, pre-tax
Reclassification adjustment for net losses/(gains) included in net income, tax
Reclassification adjustment for net losses/(gains) included in net income, net of tax
Total other comprehensive (loss)/income, pre-tax			3,113,000	516,000
Total other comprehensive (loss)/income, tax			920,000	217,000
Total other comprehensive (loss)/income, net of tax			2,193,000	299,000
Ending balance, loss, net of tax			427,000	(1,871,000)
AOCI Attributable to Parent [Member]
Beginning balance, loss, net of tax		$ (2,511,000)	(2,511,000)	(3,715,000)
Reclassification adjustment for stranded tax effects of Tax Cuts and Job Act, tax	[1]		515,000
Reclassification adjustment for stranded tax effects of Tax Cuts and Job Act, net of tax	[1]		(515,000)
Reclassification adjustment for equity securities, pre-tax	[2]		(12,151,000)
Reclassification adjustment for equity securities, tax	[2]		(3,592,000)
Reclassification adjustment for equity securities, net of tax	[2]		(8,559,000)
Net unrealized (losses)/gains arising during the period, pre-tax			(13,233,000)	(340,000)
Net unrealized (losses)/gains arising during the period, tax			(3,912,000)	(143,000)
Net unrealized (losses)/gains arising during the period, net of tax			(9,321,000)	(197,000)
Reclassification adjustment for net losses/(gains) included in net income, pre-tax				466,000
Reclassification adjustment for net losses/(gains) included in net income, tax				196,000
Reclassification adjustment for net losses/(gains) included in net income, net of tax				270,000
Total other comprehensive (loss)/income, pre-tax			(13,233,000)	126,000
Total other comprehensive (loss)/income, tax			(3,912,000)	53,000
Total other comprehensive (loss)/income, net of tax			(9,321,000)	73,000
Ending balance, loss, net of tax			$ (20,906,000)	$ (3,642,000)

[1] These amounts were recorded as of January 1, 2018 as a result of the adoption of ASU 2018-2.

[2] This amount was recorded as of January 1, 2018 as a result of the adoption of ASU 2016-1.