Common Stock (Tables)

12 Months Ended

Dec. 31, 2017

Share-based Compensation Arrangement by Share-based Payment Award [Line Items]

Schedule of Treasury Stock by Class

Detail regarding the Company's stock repurchase program are presented below:

	Since 1999 (a)		Authorized Shares
Shares repurchased (b)	25,406,184
Cost, including commission (in thousands)	$	423,647
Total remaining shares available for repurchase at December 31, 2017			393,816

______________________

(a) Represents repurchased shares and cost since inception of the stock repurchase program in 1999.

(b) Shares repurchased does not include 86,735 treasury shares related to employee compensation arrangements outside of the Company's repurchase programs. Beginning in 2015, shares of the Company's common stock issued for employee benefit and stock incentive plans have been issued from the shares repurchased and held in treasury stock. The Company awarded 256,929 shares, net of shares withheld for taxes, out of treasury stock during 2017.

Schedule of Earnings Per Share, Basic and Diluted

The basic and diluted earnings per share are presented below:

	Years Ended December 31,
	2017			2016			2015
Weighted average number of common shares outstanding:
Basic number of common shares outstanding	40,414,556			40,350,688			40,274,986
Dilutive effect of unvested performance awards	120,635			57,345			33,576
Diluted number of common shares outstanding	40,535,191			40,408,033			40,308,562
Basic net income per common share:
Net income	$	98,261		$	96,768		$	81,918
Income allocated to participating restricted stock	(368		)	(321		)	(243		)
Net income available to common shareholders	$	97,893		$	96,447		$	81,675
Diluted net income per common share:
Net income	$	98,261		$	96,768		$	81,918
Income reallocated to participating restricted stock	(368		)	(321		)	(243		)
Net income available to common shareholders	$	97,893		$	96,447		$	81,675
Basic net income per common share:
Distributed earnings	$	1.315		$	1.225		$	1.165
Undistributed earnings	1.105			1.165			0.865
Basic net income per common share	$	2.420		$	2.390		$	2.030
Diluted net income per common share:
Distributed earnings	$	1.315		$	1.225		$	1.165
Undistributed earnings	1.105			1.165			0.865
Diluted net income per common share	$	2.420		$	2.390		$	2.030

Schedule of Antidilutive Securities Excluded from Computation of Earnings Per Share

The amount of restricted stock awards and performance shares at 100% performance level excluded from the calculation of the diluted number of common shares outstanding because their effect was antidilutive is presented below:

	Year Ended December 31,
	2017	2016	2015
Restricted stock awards	67,739	53,703	56,375
Performance shares (a)	—	47,246	66,804

_____________________

(a) Certain performance shares were excluded from the computation of diluted earnings per share as no payouts would have been required based upon performance at the end of each corresponding period.

Restricted Stock

Share-based Compensation Arrangement by Share-based Payment Award [Line Items]

Schedule of Expense, Deferred Tax Benefit, and Current Tax Expense Related to Restricted Stock Awards

The expense, deferred tax benefit, and current tax expense recognized related to restricted stock and other stock-based awards in 2017, 2016 and 2015 is presented below (in thousands):

	2017		2016		2015
Expense (a)	$	2,997	$	2,594	$	2,755
Deferred tax benefit	1,049		908		964
Current tax benefit recognized	318		183		43

_____________________

(a) Any capitalized costs related to these expenses is less than $0.3 million for all years.

Schedule of Share-based Compensation, Activity

The aggregate intrinsic value and fair value at grant date of restricted stock and other stock-based awards which vested in 2017, 2016 and 2015 is presented below (in thousands):

	2017		2016		2015
Aggregated intrinsic value	$	3,711	$	2,515	$	3,451
Fair value at grant date	2,803		1,993		3,327

Schedule of Restricted Stock Activity

The unvested restricted stock transactions for 2017 are presented below:

	Total Shares		Weighted Average Grant Date Fair Value		Unrecognized Compensation Expense (a)		Aggregate Intrinsic Value
					(In thousands)		(In thousands)
Restricted shares outstanding at December 31, 2016 (b)	109,393		$	39.90
Stock awards	70,273		49.78
Vested	(68,470	)	40.93
Forfeitures	(4,961	)	40.18
Restricted shares outstanding at December 31, 2017 (b)	106,235		45.76		$	2,005	$	5,880

_______________________

(a) The unrecognized compensation expense is expected to be recognized over the weighted average remaining contractual term of the outstanding restricted stock of approximately one year.

(b) Excludes the stock based retention grant to the President and Chief Executive Officer ("CEO") of 27,624 shares. See "Restricted Stock with a Market Condition (Performance Shares)" section below for further details.

Schedule of Share-based Compensation Award, Restricted Stock, Grants in Period, Weighted Average Grant Date Fair Value

The weighted average fair value per share at grant date for restricted stock and other stock-base awards granted during 2017, 2016 and 2015 were:

	2017		2016		2015
Weighted average fair value per share	$	49.78	$	40.95	$	37.17

Performance Shares

Share-based Compensation Arrangement by Share-based Payment Award [Line Items]

Schedule of Share-based Compensation, Activity

A summary of information related to performance shares for 2017, 2016 and 2015 is presented below:

	2017		2016		2015
Weighted average per share grant date fair value per share of performance shares awarded	$	42.62	$	38.11	$	35.72
Fair value of performance shares vested (in thousands)	298		—		—
Intrinsic value of performance shares vested (in thousands) (a)	512		—		—
Compensation expense (in thousands) (b) (c)	2,012		1,655		1,042
Deferred tax benefit related to compensation expense (in thousands) (b)	704		579		365

_____________________

(a) Based on a 100% performance level.

(b) Includes adjustments for estimated forfeitures.

(c) Includes CEO retention grant.

Schedule of Share-based Compensation Award, Performance-Based Units, Vested and Expected to Vest

Detail of performance shares vested follows:

Date Vested	Payout Ratio		Performance Shares Awarded	Compensation Costs Expensed		Period Compensation Costs Expensed	Aggregated Intrinsic Value
				(In thousands)			(In thousands)
January 31, 2018	175	%	68,379	$	1,499	2015-2017	$	3,569
January 25, 2017	32	%	11,314	932		2014-2016	512
January 27, 2016	0	%	0	851		2013-2015	—
February 20, 2015	0	%	0	1,502		2012-2014	—

Schedule of Performance Stock Activity

The outstanding performance share awards at the 100% performance level is summarized below:    

	Number Outstanding		Weighted Average Grant Date Fair Value		Unrecognized Compensation Expense (b)		Aggregate Intrinsic Value
					(In thousands)		(In thousands)
Performance shares outstanding at December 31, 2016 (a)	166,444		$	34.40
Performance share awards	51,493		42.62
Performance shares vested	(11,314	)	26.36
Performance shares expired	(24,057	)	26.36
Performance shares forfeited	(9,975	)	39.53
Performance shares outstanding at December 31, 2017 (a)	172,591		38.21		$	2,048	$	9,553

_______________________

(a) On December 15, 2015, the Company issued a stock based retention grant to the President and CEO of 27,624 shares in accordance with the Amended and Restated 2007 LTIP that is eligible for vesting based on the achievement of certain performance conditions and a five year service period, as stated in the CEO's employment agreement. The performance condition was met as of November 2016 as determined by the Compensation Committee, and has been included in the beginning and ending balance in the table above.

(b) The unrecognized compensation expense is expected to be recognized over the weighted average remaining contractual term of the awards of approximately one year, except for the CEO retention grant.