Note 12 - Income Taxes Summary of Income Tax Examinations (Details) (Internal Revenue Service (IRS) [Member], USD $) In Millions, unless otherwise specified	Mar. 31, 2015	Sep. 04, 2014	May 03, 2010	Jun. 30, 2008
Income Tax Examination [Line Items]
Income Tax Examination, Amount of Claimed Income Tax Refund Being Disallowed for Tax Years 2006 and 2007		$ 105
REMIC Residual [Member]
Income Tax Examination [Line Items]
Qualified Deposit With The U.S. Department Of Treasury Relating to Tax Years 2000 Through 2004				85
Qualified Deposit With The U.S. Department Of Treasury Relating To Tax Years 2005 Through 2007			4
Income Tax Examination, Notice of Deficiency, Amounts Related to Unpaid Taxes and Penalties		157
Income Tax Examination, Estimated Interest on Notice of Deficiency Amounts	118
Income Tax Examination, Proposed State Liabilities Resulting from IRS Examination of Tax Years 2000 Through 2007	$ 30