Note 7 - Available-for-Sale Investments - Summary of Fair Value of Available-for-Sale Investments (Details) - USD ($) $ in Millions		Jun. 30, 2016	Dec. 31, 2015
US Government Agencies Debt Securities [Member]
Amortized cost			$ 100
Fair value			100
Total Short-Term Investments [Member]
Amortized cost			100
Fair value			100
Asset-backed Securities [Member]
Amortized cost	[1]	34	37
Fair value	[1]	30	33
Total Long-Term Investments [Member]
Amortized cost		34	37
Fair value		$ 30	$ 33

[1] Due after 10 years and are being reported at their final maturity dates.