Stock Award Plans (Tables)

12 Months Ended

Dec. 31, 2018

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

Compensation Cost Breakdown in Statement of Earnings

The Company has share-based compensation plans which are described below. The compensation cost that has been charged against earnings for the Company’s stock award plans and the income tax benefit recognized in the statement of earnings for stock awards for the years ended December 31, 2018, 2017 and 2016 were as follows (in thousands):

	2018		2017		2016
Compensation cost	$	19,104	$	11,460	$	11,675
Income tax benefit	$	5,903	$	4,333	$	4,378

Stock Option Valuation Assumptions

The key input variables used in valuing the stock options during the years ended December 31, 2018, 2017 and 2016 were as follows:

	2018			2017			2016
Dividend yield	None			None			None
Average risk-free interest rate		2.7	%		2.0	%		1.5	%
Stock price volatility		27	%		27	%		30	%
Estimated option term		Six years			Six years			Six years

Employee Plan [Member]

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

Stock Option Activity

The following is a summary of the stock option activity under the employee plan described above for the years ended December 31, 2018, 2017 and 2016:

	Outstanding Non- Qualified or Nonincentive Stock Awards			Weighted Average Exercise Price
Outstanding at December 31, 2015		430,432		$	71.01
Granted		186,706		$	53.50
Canceled or expired		(16,017	)	$	80.17
Outstanding at December 31, 2016		601,121		$	65.33
Granted		123,141		$	68.46
Exercised		(36,616	)	$	47.95
Canceled or expired		(32,991	)	$	74.07
Outstanding at December 31, 2017		654,655		$	66.45
Granted		115,797		$	75.50
Exercised		(283,886	)	$	61.81
Canceled or expired		(21,864	)	$	102.42
Outstanding at December 31, 2018		464,702		$	69.85

Outstanding and Exercisable Stock Options

The following table summarizes information about the Company’s outstanding and exercisable stock options under the employee plan at December 31, 2018:

	Options Outstanding							Options Exercisable
Range of Exercise Prices	Number Outstanding		Weighted Average Remaining Contractual Life in Years		Weighted Average Exercise Price		Aggregated Intrinsic Value	Number Exercisable		Weighted Average Exercise Price		Aggregated Intrinsic Value
$51.23		90,975		4.1	$	51.23			57,438	$	51.23
$64.65 – $68.50		126,260		4.7	$	67.23			41,146	$	67.40
$70.65 – $75.50		207,156		4.5	$	74.56			91,359	$	73.36
$93.64 – $101.46		40,311		2.1	$	95.90			40,311	$	95.90
$51.23 – $101.46		464,702		4.3	$	69.85	$1,570,000		230,254	$	70.72	$951,000

Restricted Stock Award Activity

The following is a summary of the restricted stock award activity under the employee plan described above for the years ended December 31, 2018, 2017 and 2016:

	Unvested Restricted Stock Award Shares			Weighted Average Grant Date Fair Value Per Share
Nonvested balance at December 31, 2015		311,727		$	75.73
Granted		190,610		$	53.56
Vested		(105,109	)	$	69.93
Forfeited		(19,573	)	$	76.06
Nonvested balance at December 31, 2016		377,655		$	66.14
Granted		127,255		$	68.50
Vested		(105,600	)	$	68.91
Forfeited		(35,189	)	$	69.45
Nonvested balance at December 31, 2017		364,121		$	65.84
Vested		(144,265	)	$	72.66
Forfeited		(5,640	)	$	64.60
Nonvested balance at December 31, 2018		214,216		$	64.73

RSU Activity

The following is a summary of RSU activity under the employee plan described above for the year ended December 31, 2018:

	UnvestedRSUs			Weighted AverageGrant Date Fair Value Per Unit
Nonvested balance at December 31, 2017		—		$	—
Granted		143,890		$	75.59
Forfeited		(2,835	)	$	75.50
Nonvested balance at December 31, 2018		141,055		$	75.59

Director Plan [Member]

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

Stock Option Activity

The following is a summary of the stock option activity under the director plan described above for the years ended December 31, 2018, 2017, and 2016:

	Outstanding Non- Qualified or Nonincentive Stock Awards			Weighted Average Exercise Price
Outstanding at December 31, 2015		220,429		$	64.37
Exercised		(9,000	)	$	35.72
Canceled or expired		(6,000	)	$	99.52
Outstanding at December 31, 2016		205,429		$	64.60
Granted		3,188		$	70.65
Exercised		(39,000	)	$	46.23
Canceled or expired		(12,000	)	$	87.35
Outstanding at December 31, 2017		157,617		$	67.54
Granted		2,640		$	85.30
Exercised		(29,153	)	$	57.47
Outstanding at December 31, 2018		131,104		$	70.14

Outstanding and Exercisable Stock Options

The following table summarizes information about the Company’s outstanding and exercisable stock options under the director plan at December 31, 2018:

	Options Outstanding							Options Exercisable
Range of Exercise Prices	Number Outstanding		Weighted Average Remaining Contractual Life in Years		Weighted Average Exercise Price		Aggregate Intrinsic Value	Number Exercisable		Weighted Average Exercise Price		Aggregate Intrinsic Value
$29.60		6,000		0.3	$	29.60			6,000	$	29.60
$41.24 – $56.45		31,276		1.9	$	50.61			31,276	$	50.61
$61.89 – $62.48		28,000		3.6	$	62.27			28,000	$	62.27
$70.65 – $99.52		65,828		5.2	$	86.45			65,168	$	86.47
$29.60 – $99.52		131,104		3.8	$	70.14	$893,000		130,444	$	70.06	$893,000

Restricted Stock Award Activity

The following is a summary of the restricted stock award activity under the director plan described above for the years ended December 31, 2018, 2017 and 2016:

	Unvested Restricted Stock Award Shares			Weighted Average Grant Date Fair Value Per Share
Nonvested balance at December 31, 2015		1,791		$	68.73
Granted		23,074		$	64.89
Vested		(24,518	)	$	65.17
Nonvested balance at December 31, 2016		347		$	64.89
Granted		21,198		$	70.65
Vested		(21,226	)	$	70.56
Nonvested balance at December 31, 2017		319		$	70.65
Granted		21,373		$	85.70
Vested		(21,428	)	$	85.48
Nonvested balance at December 31, 2018		264		$	85.30