Stock-Based Compensation (Tables)

12 Months Ended

Dec. 31, 2015

Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]

Summary Information for Stock Options

The following table includes summary information for stock options as of December 31, 2015:

	Number of Options			Weighted- Average Exercise Price		Weighted-Average Remaining Contractual Life (years)
Outstanding at January 1, 2015		1,054,435		$	96.53
Granted		55,244		$	154.58
Exercised		(367,497	)	$	101.31
Terminated		(56,170	)	$	135.85
Outstanding at December 31, 2015		686,012		$	95.43		3.8
Exercisable at December 31, 2015		544,755		$	87.75		2.7

Summary of Information for Incentive Compensation Awards and Restricted Stock Awards

The following table summarizes information for incentive compensation awards and restricted stock awards as of December 31, 2015:

	Incentive Compensation					Restricted Stock - Service Based					Restricted Stock - Performance Based
	Number of Awards			Weighted- Average Grant-Date Fair Value		Number of Awards			Weighted- Average Grant-Date Fair Value		Number of Awards		Weighted- Average Grant-Date Fair Value
January 1, 2015		27,608		$	101.61		319,230		$	105.62		16,388	$	129.14
Awarded		22,035		$	108.53		48,368		$	154.26		20,219	$	108.53
Distributed		(11,751	)	$	99.14		(75,411	)	$	77.27		—	$	—
Forfeited		(552	)	$	102.99		(3,624	)	$	127.06		—	$	—
December 31, 2015		37,340		$	106.45		288,563		$	120.92		36,607	$	117.76

Schedule of Stock-Based Compensation Expense

The following table summarizes stock-based compensation expense for the years ended December 31, 2015, 2014 and 2013, unrecognized compensation cost for nonvested awards at December 31, 2015 and the weighted-average period over which unrecognized compensation cost is expected to be recognized:

(add 000, except year data)	Stock Options		Restricted Stock		Incentive Compensation		Directors’ Awards		Total
Stock-based compensation expense recognized for years    ended December 31:
2015	$	2,679	$	9,809	$	376	$	725	$	13,589
2014	$	2,020	$	6,189	$	257	$	527		8,993
2013	$	1,734	$	4,377	$	229	$	668		7,008
Unrecognized compensation cost at December 31, 2015:	$	2,718	$	18,985	$	334	$	—	$	22,037
Weighted-average period over which unrecognized    compensation cost will be recognized:	2.0 years		2.8 years		1.5 years			—

Schedule of Unrecognized Compensation Cost, Nonvested Awards

The following presents expected stock-based compensation expense in future periods for outstanding awards as of December 31, 2015:

(add 000)
2016	$	9,818
2017		6,578
2018		3,817
2019		1,824
2020		—
Total	$	22,037