Note 7 - Available-for-Sale Investments (Details) - Summary of Fair Value of Available-for-Sale Investments - USD ($) $ in Millions		Mar. 31, 2016	Dec. 31, 2015
US Government Agencies Debt Securities [Member]
Bonds, notes and other securities:
Amortized cost		$ 0	$ 100
Fair value		0	100
Total Short-Term Investments [Member]
Bonds, notes and other securities:
Amortized cost		0	100
Fair value		0	100
Asset-backed Securities [Member]
Bonds, notes and other securities:
Amortized cost	[1]	37	37
Fair value	[1]	32	33
Total Long-Term Investments [Member]
Bonds, notes and other securities:
Amortized cost		37	37
Fair value		$ 32	$ 33

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