Note 3 - Share-based Compensation (Tables)

3 Months Ended

Mar. 31, 2019

Notes Tables

Share-based Payment Arrangement, Expensed and Capitalized, Amount [Table Text Block]

	Three Months Ended March 31,
	2019		2018
Restricted share units:
Pretax compensation expense	$	9,741	$	8,591
Tax benefit		2,435		2,234
Restricted share unit expense, net of tax	$	7,306	$	6,357
Performance share units:
Pretax compensation expense	$	3,830	$	3,445
Tax benefit		957		896
Performance share unit expense, net of tax	$	2,873	$	2,549