Note 3 - Share-based Compensation

3 Months Ended

Mar. 31, 2018

Notes to Financial Statements

Disclosure of Compensation Related Costs, Share-based Payments [Text Block]

3 . Share-b ased Compensation

The following table summarizes the components of our share-based compensation program expense (in thousands):

	Three Months Ended March 31,
	2018		2017
Restricted share units:
Pretax compensation expense	$	8,591	$	8,136
Tax benefit		2,234		2,278
Restricted share unit expense, net of tax	$	6,357	$	5,858
Performance share units:
Pretax compensation expense	$	3,445	$	3,034
Tax benefit		896		849
Performance share unit expense, net of tax	$	2,549	$	2,185

As of

March 31, 2018,

we had

$77.2

million and

$24.8

million of total unrecognized compensation expense related to restricted share units and performance share units, respectively, that is to be recognized over the remaining weighted-average period of approximately

3.6

years for restricted share units and

2.6

years for performance share units. During the

first

quarter

2018,

we issued

3,432

shares for vested restricted share units.