Share-Based Compensation (Tables)

9 Months Ended

Sep. 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	19.8%	19.1%
Expected lives	3.4 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:

	Nine Months Ended
	September 30,
	2017		2016
Options outstanding January 1,	541,679		741,676
Options granted under 2012 Plan	495,000		470,000
Options exercised under 2012 Plan	(155,829	)	(608,331	)
Options forfeited under 2012 Plan	(6,668	)	—
Options exercised under 2005 Plan	(15,000	)	(61,666	)
Options outstanding, September 30,	859,182		541,679
Exercisable at September 30,	465,831		188,331