Stock Incentive Plan (Tables)

12 Months Ended

Dec. 31, 2015

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

Compensation cost, net of forfeitures, related to stock-based compensation

The following table summarizes the compensation cost, net of forfeitures, related to stock-based compensation for the years ended December 31, 2015, 2014 and 2013:

	2015			2014			2013
Stock and stock unit awards:
Pre-tax compensation expense	$	378		$	376		$	339
Income tax benefit	(132		)	(132		)	(118		)
Total share-based compensation expense, net of income taxes	$	246		$	244		$	221

Summary of option activity

A summary of option activity under the SI Plan and the 1997 Stock Incentive Plan as of December 31, 2015, 2014 and 2013, and changes during the years then ended is presented below:

	2015
	Shares	Weighted-Average Exercise Price	Weighted-Average Remaining Contractual Term	Aggregate Intrinsic Value
Outstanding, beginning of year	52,000	$24.64
Granted	0	0.00
Exercised	0	0.00
Forfeited or expired	6,500	24.43
Outstanding, end of year	45,500	$24.67	2.42	$	63,000
Exercisable, end of year	45,500	$24.67	2.42	$	63,000

There were no options exercised during 2015. Stock options for 24,500 shares of common stock were not considered in computing the aggregate intrinsic value of outstanding shares and exercisable shares for 2015 because they were anti-dilutive.

	2014
	Shares	Weighted-Average Exercise Price	Weighted-Average Remaining Contractual Term	Aggregate Intrinsic Value
Outstanding, beginning of year	128,750	$26.20
Granted	0	0.00
Exercised	0	0.00
Forfeited or expired	76,750	27.25
Outstanding, end of year	52,000	$24.64	3.43	$	—
Exercisable, end of year	52,000	$24.64	3.43	$	—

There were no options exercised during 2014. Stock options for 52,000 shares of common stock were not considered in computing the aggregate intrinsic value of outstanding shares and exercisable shares for 2014 because they were anti-dilutive.

	2013
	Shares	Weighted-Average Exercise Price	Weighted-Average Remaining Contractual Term	Aggregate Intrinsic Value
Outstanding, beginning of year	176,625	$24.88
Granted	0	0.00
Exercised	39,373	20.67
Forfeited or expired	8,502	24.34
Outstanding, end of year	128,750	$26.20	2.44	$	—
Exercisable, end of year	128,750	$26.20	2.44	$	—

The total intrinsic value of options exercised during 2013 was $75,000. Stock options for 128,750 shares of common stock were not considered in computing the aggregate intrinsic value of outstanding shares and exercisable shares for 2013 because they were anti-dilutive.

Stock options, by exercise price range

The following table summarizes information about stock options under the SI Plan outstanding at December 31, 2015:

		Options Outstanding		Options Exercisable
Range of Exercise Prices	Number Outstanding	Weighted-Average Remaining Contractual Life	Weighted-Average Exercise Price	Number Exercisable	Weighted-Average Exercise Price
$22.50 to $24.50	21,000	2.96	$23.00	21,000	$23.00
$24.50 to $26.50	24,500	1.95	$26.10	24,500	$26.10
	45,500	2.42	$24.67	45,500	$24.67

Schedule of Unvested Restricted Stock and Restricted Stock Units Roll Forward [Table Text Block]

The following table summarizes non-vested stock and stock unit activity for the years ended December 31, 2015, 2014 and 2013:

	2015			2014			2013
	Shares	Weighted-avg Grant-date Fair Value		Shares	Weighted-avg Grant-date Fair Value		Shares	Weighted-avg Grant-date Fair Value
Nonvested, beginning of year	26,897	$22.95		24,799	$24.16		25,337	$22.16
Granted	18,002	20.14		19,377	22.00		14,054	23.46
Vested	(14,730)	23.77		(14,499)	23.72		(14,592)	20.01
Forfeited	0	0.00		(2,780)	23.12		0	0.00
Nonvested, end of year	30,169	$20.87		26,897	$22.95		24,799	$24.16
Fair value of shares vested		$	350,075		$	343,910		$	329,721