Share-Based Compensation (Tables)

9 Months Ended

Sep. 30, 2016

Shares awarded to non-employee directors [Line Items]

Schedule of Compensation Cost for Share-based Payment Arrangements, Allocation of Share-based Compensation Costs by Plan

The table below presents the amounts included in net income related to share-based compensation expense for the three and nine months endedSeptember 30, 2016 and 2015:

	Three Months Ended						Nine Months Ended
	September 30,						September 30,
	2016			2015			2016			2015
(in thousands)
Awards to non-employee directors	$	135		$	165		$	445		$	475
Awards to key employees	488			334			1,442			970
Total compensation expense	623			499			1,887			1,445
Less: tax benefit	(251		)	(201		)	(760		)	(582		)
Share-based compensation amounts included in net income	$	372		$	298		$	1,127		$	863

Schedule of Share-based Compensation, Nonemployee Director Stock Award Plan, Activity [Table Text Block]

	Number of Shares		Weighted Average Fair Value
Outstanding— December 31, 2015	—		$	—
Granted	8,577		$	62.90
Vested	(8,577	)	$	62.90
Outstanding— September 30, 2016	—		$	—

Award to key employees [Member]

Shares awarded to non-employee directors [Line Items]

Schedule of Share-based Compensation, Activity

The table below presents the summary of the stock activity for awards to key employees for the nine months endedSeptember 30, 2016:

	Number of Shares		Weighted Average Fair Value
Outstanding— December 31, 2015	110,398		$	38.34
Granted	46,571		$	67.90
Vested	(39,553	)	$	31.79
Expired	(2,325	)	$	42.25
Outstanding— September 30, 2016	115,091		$	52.36