Share-Based Payments (Tables)

3 Months Ended

Mar. 31, 2015

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

Summary of Shares Available for Grant and Stock Option Activity

A summary of shares available for grant and activity is detailed below.

		Options Outstanding
	Shares Available For Grant	Shares	Weighted- Average Exercise Price
Stock Options:
Balance at January 1, 2015	291,000	29,768	$	242.48
Exercised	—	—	$	—
Forfeited	—	—	$	—
Expired	—	—	$	—
Stock options granted	—	—	$	—
Balance at March 31, 2015	291,000	29,768	$	242.48

Schedule of Stock Appreciation Rights Activity

	Stock Appreciation Rights Outstanding
	Awards		Weighted- Average Exercise Price
Stock Appreciation Rights:
Balance at January 1, 2015	92,186		$	157.71
Exercised	(775	)	$	116.95
Forfeited	—		$	—
Granted	—		$	—
Balance at March 31, 2015	91,411		$	158.05

Summary of Information About Stock Options and SARs Outstanding

The following table summarizes information about stock options and SARs outstanding at March 31, 2015.

	Options/SARs Outstanding
	Number Outstanding		Weighted- Average Remaining Contractual Life	Number Exercisable
Exercise prices:
$255.13 (options)	21,768		3.0 years	17,615
$208.05 (options)	8,000		3.2 years	8,000
$236.00 (SARs)	250		3.4 years	200
$114.64 (SARs)	25,243		3.9 years	21,064
$132.56 (SARs)	30,418		6.7 years	9,604
$210.22 (SARs)	35,500		8.7 years	2,800
Totals	121,179			59,283
Aggregate intrinsic value (in thousands)	$	9,168		$	4,608

Summary of Assumptions Employed Using Black-Scholes Option Pricing Model

In estimating the fair value of the options outstanding at March 31, 2015 and December 31, 2014, the Company employed the Black-Scholes option pricing model with assumptions detailed below.

	March 31, 2015		December 31, 2014
Expected term of options	3.0 to 8.7 years		3.3 to 9.0 years
Expected volatility:
Range	21.30% to 37.77%		19.67% to 37.75%
Weighted-average	24.30	%	22.91	%
Expected dividend yield	0.14	%	0.13	%
Risk-free rate:
Range	0.22% to 1.47%		0.13% to 1.62%
Weighted-average	0.49	%	0.56	%