Note 6 - Income Taxes (Details) - Deferred Tax Assets for Loss and Tax Credit Carryforwards - USD ($) $ in Millions	Dec. 31, 2015	Dec. 31, 2014
Note 6 - Income Taxes (Details) - Deferred Tax Assets for Loss and Tax Credit Carryforwards [Line Items]
Net operating losses	$ 406
Tax credits	745
Totals as of December 31, 2015	1,151	$ 1,235
2016-2020 [Member]
Note 6 - Income Taxes (Details) - Deferred Tax Assets for Loss and Tax Credit Carryforwards [Line Items]
Net operating losses	127
Tax credits	414
Totals as of December 31, 2015	541
2021-2025 [Member]
Note 6 - Income Taxes (Details) - Deferred Tax Assets for Loss and Tax Credit Carryforwards [Line Items]
Net operating losses	63
Tax credits	58
Totals as of December 31, 2015	121
2026-2035 [Member]
Note 6 - Income Taxes (Details) - Deferred Tax Assets for Loss and Tax Credit Carryforwards [Line Items]
Net operating losses	3
Tax credits	237
Totals as of December 31, 2015	240
Indefinite [Member]
Note 6 - Income Taxes (Details) - Deferred Tax Assets for Loss and Tax Credit Carryforwards [Line Items]
Net operating losses	213
Tax credits	36
Totals as of December 31, 2015	$ 249