Note 2 - Summary of Significant Accounting Policies - Basic and Diluted Earnings Per Share Computation (Details) - shares shares in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Weighted average basic shares outstanding (in shares)	109,375	109,987	112,474
Effect of common stock equivalents (in shares)	1,053	1,062	887
Weighted average shares outstanding – diluted (in shares)	110,428	111,049	113,361