Note 6 - Income Taxes - Deferred Tax Assets for Loss and Tax Credit Carryforwards (Details) - USD ($) $ in Millions	Dec. 31, 2016	Dec. 31, 2015
Net operating losses	$ 416
Tax credits	1,049
Totals as of December 31, 2016	1,465	$ 1,151
Tax Years 2017 Through 2021 [Member]
Net operating losses	144
Tax credits	420
Totals as of December 31, 2016	564
Tax Years 2022 Through 2026 [Member]
Net operating losses	46
Tax credits	70
Totals as of December 31, 2016	116
Tax Years 2027 Through 2036 [Member]
Net operating losses	8
Tax credits	523
Totals as of December 31, 2016	531
Indefinite [Member]
Net operating losses	218
Tax credits	36
Totals as of December 31, 2016	$ 254