Stock-Based Compensation (Tables)

12 Months Ended

Dec. 31, 2016

Share-based Compensation [Abstract]

Summary of Stock Option Activity [Table Text Block]

	2015	2014
Number of shares under the plans:
Outstanding and exercisable at beginning of year	7,500	18,750
Granted	-	-
Canceled	-	-
Exercised	(7,500)	(11,250)
Outstanding and exercisable at end of year	-	7,500

Schedule of Nonvested Share Activity [Table Text Block]

	Restricted	Performance		Weighted Average
	Stock	Stock		Grant Date
	Units	Units		Fair Value
Outstanding at January 1, 2014	129,726	61,651	$	34.00
Granted	19,051	34,652		44.07
Vested	(40,540)	(13,588)		34.59
Adjustment for incentive awards not expected to vest	-	(7,845)		43.59
Canceled	-	(2,880)		44.13
Outstanding at December 31, 2014	108,237	71,990	$	36.25
Granted	29,656	41,114		44.93
Vested	(39,076)	(23,877)		32.35
Adjustment for incentive awards not expected to vest	-	(53,228)		43.26
Canceled	(5,000)	-		44.84
Outstanding at December 31, 2015	93,817	35,999	$	39.66
Granted	48,283	129,844		12.50
Vested	(56,807)	-		28.45
Adjustment for incentive awards not expected to vest	-	(93,103)		24.79
Canceled	(6,021)	(9,050)		18.82
Outstanding at December 31, 2016	79,272	63,690	$	21.66

Disclosure of Share-based Compensation Arrangements by Share-based Payment Award [Table Text Block]

	2016	2015	2014
Number of shares available for future grant:
Beginning of year	407,307	469,840	513,280
End of year	675,447	407,307	469,840