Stock-Based Compensation (Tables)

12 Months Ended

Dec. 31, 2017

Share-based Compensation [Abstract]

Summary of Stock Option Activity

No stock options were outstanding during the years ended December 31, 2017 and 2016. Certain information for the year ended December 31, 2015 relative to employee stock options is summarized as follows:

	2015
Number of shares under the plans:
Outstanding and exercisable at beginning of year	7,500
Granted	—
Canceled	—
Exercised	(7,500	)
Outstanding and exercisable at end of year	—

Schedule of Nonvested Share Activity

The following table summarizes the restricted stock award, deferred stock, and performance unit award activity for the three-year periods ended December 31, 2017, 2016, and 2015:

	Restricted Stock		Deferred Stock	Performance Stock Units		Weighted Average Aggregate Grant Date Fair Value
Outstanding at January 1, 2015	108,237		—	71,990		$	36.25
Granted	29,656		—	41,114		44.93
Vested	(39,076	)	—	(23,877	)	32.35
Adjustment for incentive awards expected to vest	—		—	(53,228	)	43.26
Canceled and forfeited	(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 and forfeited	(6,021	)	—	(9,050	)	18.82
Outstanding at December 31, 2016	79,272		—	63,690		$	21.66
Granted	175,196		26,860	120,583		14.46
Vested	(22,808	)	—	—		28.88
Adjustment for incentive awards not expected to vest	—		—	46,130		19.00
Canceled and forfeited	(44,854	)	—	(49,062	)	15.40
Outstanding at December 31, 2017	186,806		26,860	181,341		$	16.53

Disclosure of Share-based Compensation Arrangements by Share-based Payment Award

The following table presents the number of shares available for future grants:

	2017	2016	2015
Number of shares available for future grant:
Beginning of year	675,447	407,307	469,840
End of year	639,390	675,447	407,307