6.	Share-based Compensation

We maintain a Management Incentive Plan (the “Plan”) that provides various share-based financial methods to compensate our key employees with shares of our common stock or common stock equivalents. Under the Plan, as amended, we have, from time to time, utilized restricted share units, performance share units, restricted shares, and nonstatutory stock options to compensate our employees and directors. We currently are utilizing restricted and performance share units.

Our restricted share units have various vesting schedules generally ranging from

years when awarded. These restricted share units do not contain rights to vote or receive dividends until the vesting date. Unvested restricted share units are forfeited if the employee terminates for any reason other than death, disability, or special circumstances as determined by the Compensation Committee. Restricted share units are valued based on the fair value of the award on the grant date, adjusted for dividend estimates based on grant date dividend rates.

Our performance share units vest based on the passage of time (generally

years) and achievement of performance criteria. Performance share units do not contain rights to vote or receive dividends until the vesting date. Unvested performance share units are forfeited if the employee terminates for any reason other than death or disability. Performance shares are valued based on the fair value of the award on the grant date, adjusted for dividend estimates based on grant date dividend rates.

In the past, nonstatutory stock options have been granted to key employees for the purchase of our common stock for

100%

of the fair market value of the common stock at the grant date as awarded by the Compensation Committee. These options generally vested over a

-year period and were forfeited immediately if the employee terminated for any reason other than death, disability or retirement after age

55.

We did

not

grant any stock options during the years ended

December

31,

2016,

2015,

and

2014.

An employee is allowed to surrender shares of common stock that the employee has owned for at least

six

months in full or partial payment of the option price of an option being exercised and/or to satisfy tax withholding obligations incident to the vesting of restricted share units, performance share units, or the exercise of an option.

We account for our restricted share units, performance share units, and stock options in accordance with current accounting standards for share-based payments. These standards require that the cost of all share-based payments to employees, including grants of employee stock options, be recognized in our Consolidated Financial Statements based on the grant date fair value of those awards. This cost is recognized over the period for which an employee is required to provide service in exchange for the award, subject to the attainment of performance metrics established for performance share units. Share-based compensation expense is recorded in salaries, wages, and employee benefits in our Consolidated Statements of Earnings, along with other compensation expenses to employees. The following table summarizes the components of our share-based compensation program expense (in thousands):

	Years ended December 31,
	2016		2015		2014
Restricted share units
Pretax compensation expense	$	29,938	$	27,898	$	27,256
Tax benefit		11,347		10,629		10,360
Restricted share units, net of tax	$	18,591	$	17,269	$	16,896
Performance share units
Pretax compensation expense	$	10,687	$	9,330	$	7,882
Tax benefit		4,050		3,555		2,996
Performance share awards, net of tax	$	6,637	$	5,775	$	4,886
Stock options
Pretax compensation expense	$	-	$	-	$	195
Tax benefit		-		-		74
Stock option expense, net of tax	$	-	$	-	$	121

A summary of our restricted share units, performance share units, and nonstatutory stock options is as follows:

Restricted Share Units	Number of Shares			Weighted Average Grant Date Fair Value
Unvested at December 31, 2013		2,421,430		$	41.49
Granted		447,780			75.61
Vested		(808,914	)		37.33
Forfeited		(119,298	)		47.81
Unvested at December 31, 2014		1,940,998		$	51.74
Granted		390,143			74.86
Vested		(783,483	)		39.45
Forfeited		(30,908	)		54.89
Unvested at December 31, 2015		1,516,750		$	63.96
Granted		540,746			75.03
Vested		(520,619	)		54.78
Forfeited		(34,221	)		69.14
Unvested at December 31, 2016		1,502,656		$	71.16

Performance Share Units	Number of Shares			Weighted Average Grant Date Fair Value
Unvested at December 31, 2013		408,025		$	56.78
Granted		106,945			76.22
Vested		(81,075	)		53.26
Forfeited		-			-
Unvested at December 31, 2014		433,895		$	62.23
Granted		160,574			74.37
Vested		(103,796	)		58.28
Forfeited		-			-
Unvested at December 31, 2015		490,673		$	67.04
Granted		142,114			74.71
Vested		(148,733	)		62.84
Forfeited		-			-
Unvested at December 31, 2016		484,054		$	70.58

Stock Options	Number of Shares (in thousands)			Weighted Average Exercise Price		Weighted Average Remaining Contractual Term (in years)		Aggregate Intrinsic Value (in millions)
Outstanding at December 31, 2013		440		$	19.08		1.67	$	25.6
Exercised		(341	)		18.70		-		19.9
Forfeited		(1	)		19.08		-		-
Outstanding at December 31, 2014		98		$	20.40		0.86	$	6.3
Exercised		(95	)		20.35		-		5.8
Forfeited		(1	)		24.27		-		-
Outstanding at December 31, 2015		2		$	20.76		0.05	$	0.1
Exercised		(2	)		20.76		-		-
Forfeited		-			-		-		-
Outstanding at December 31, 2016		-		$	-		-	$	-
Exercisable		-		$	-		-	$	-

December

31,

2016,

we had

$66.9

million and

$19.4

million of total unrecognized compensation expense related to restricted share units and performance share units, respectively, that is expected to be recognized on a straight-line basis over the remaining weighted average vesting period of approximately

3.6

years for restricted share units and

2.5

years for performance share units.

The aggregate intrinsic value of restricted and performance share units vested and options exercised during the years ended

December

31,

2016,

2015,

and

2014,

was

$56.7

million,

$80.8

million, and

$88.5

million, respectively. The aggregate intrinsic value of unvested restricted and performance share units was

$192.8

million at

December

31,

2016.

The total fair value of shares vested for restricted share, performance share, and stock option awards during the years ended

December

31,

2016,

2015,

and

2014,

was

$38.1

million,

$37.3

million, and

$37.5

million, respectively.