Note 14 - Carrying Amount of Senior Notes (Details) (Parentheticals)	Mar. 31, 2016	Dec. 31, 2015
5.625% Senior Notes Due February 2020 [Member]
Debt Instrument, Interest Rate, Stated Percentage	0.05625%	0.05625%
5.5 % Senior Notes Due 2024 [Member]
Debt Instrument, Interest Rate, Stated Percentage	0.055%	0.055%
6.000 % Senior Notes Due January 2043 [Member]
Debt Instrument, Interest Rate, Stated Percentage	0.06%	0.06%