Note 1 - Basis of Presentation - Reconciliation of Basic to Diluted Weighted-average Shares Outstanding (Details) - shares shares in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Weighted-average shares outstanding-basic (in shares)	71,636	71,879	71,777	71,850
Common stock equivalents for stock options and restricted stock (in shares)	818		714	873
Weighted-average shares outstanding-diluted (in shares)	72,454	71,879	72,491	72,723