Note 6 - Available-for-Sale Investments (Details) - Summary of Maturities of Available-for-Sale Securities (USD $) In Millions, unless otherwise specified	Mar. 31, 2015
Summary of Maturities of Available-for-Sale Securities [Abstract]
Less than one year	$ 535
Due in 1-5 years	228
Due after 10 years (1)	37	[1]
Total	$ 800

[1] Includes $37 million of asset-based securities that mature over time and are being reported at their final maturity dates.