Share-Based Compensation (Tables)

6 Months Ended

Jun. 30, 2017

Deferred Compensation Arrangements [Abstract]

Schedule of Share-based Payment Award, Stock Options, Valuation Assumptions [Table Text Block]

The fair value of each grant is estimated on the date of grant using the Black-Scholes option-pricing model with the following weighted average assumptions:

	2017	2016
Dividend yield	5.3%	6.2%
Expected volatility	19.7%	19.1%
Expected lives	3.3 years	2.9 years
Risk-free interest rate	1.49%	0.91%

Schedule of Stock Option Activity

The following table summarizes our outstanding stock options:

	Six Months Ended
	June 30,
	2017		2016
Options outstanding January 1,	541,679		741,676
Options granted under 2012 Plan	485,000		470,000
Options exercised under 2012 Plan	(70,830	)	(451,668	)
Options forfeited under 2012 Plan	(6,668	)	—
Options exercised under 2005 Plan	(15,000	)	—
Options outstanding, June 30,	934,181		760,008
Exercisable at June 30,	540,830		406,660