Share-Based Compensation (Tables)

9 Months Ended

Sep. 30, 2019

Share Based Compensation [Abstract]

Schedule of Compensation Cost for Share-based Payment Arrangements, Allocation of Share-based Compensation Costs by Plan [Table Text Block]

	Three Months Ended				Nine Months Ended
	September 30,				September 30,
	2019		2018		2019		2018
Stock options	$	455	$	267	$	888	$	785
Nonvested stock awards and restricted stock units		867		550		2,005		1,901
Employee stock purchase plan		21		24		68		68
Director stock ownership plan		27		31		81		93
Total share-based compensation expense	$	1,370	$	872	$	3,042	$	2,847

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

Number of options granted	51,610
Dividend yield	1.12	%
Expected volatility	26.29	%
Risk-free interest rate	1.52	%
Expected term (years)	4.0