Note 4 - Balance Sheet Components - Long-term Liabilities (Details) - USD ($) $ in Thousands	Mar. 31, 2019	Dec. 31, 2018
Deferred compensation plan liabilities	$ 35,310	$ 32,283
Dividend equivalents	5,670	6,145
Operating lease liabilities	996
Other	31	97
Total	$ 42,007	$ 38,525