Note 10 - Income Taxes IRS Matter (Details) - Internal Revenue Service (IRS) $ in Millions	12 Months Ended
Dec. 31, 2018 USD ($)
Income Tax Examination [Line Items]
Income Tax Expense (Benefit) Recorded as a Result of Finalized IRS Settlement	$ (73.6)
Qualified Deposit Assets With The U.S. Department Of Treasury Expected to be Submitted	31.0
Qualified Deposit Assets With The U.S. Department Of Treasury Expected to be Refunded	$ 57.2

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

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