Shareholders' Equity (Details) - USD ($)			3 Months Ended	6 Months Ended
	Jul. 18, 2019	May 01, 2019	Jun. 30, 2019	Jun. 30, 2019	Apr. 18, 2019	Dec. 31, 2018	Aug. 06, 2015
Class of Stock [Line Items]
Dividends paid (in dollars per share)			$ 0.25
Total dividends		$ 5,200,000
Common stock, outstanding (in shares)		20,404,174	20,131,854	20,131,854		20,163,816
Maximum investment under stock purchase and dividend reinvestment plan				$ 120,000
Shares issued pursuant to exercise of stock options (in shares)			4,475	34,075
Stock issued, increase in shareholders' equity			$ 82,000	$ 622,000
Stock repurchase program, number of shares authorized to be repurchased (in shares)					1,000,000
Stock repurchase program, authorized amount					$ 45,000,000
The 2015 Program
Class of Stock [Line Items]
Stock repurchase program, number of shares authorized to be repurchased (in shares)							1,200,000
Shares repurchased during period (in shares)			12,894
Shares repurchased during period, price (in dollars per share)			$ 36.35
Shares remaining authorized for repurchase (in shares)se Program, Remaining Number of Shares Authorized to be Repurchased			0	0
The 2019 Program
Class of Stock [Line Items]
Shares repurchased during period (in shares)			28,476
Shares repurchased during period, price (in dollars per share)			$ 37.82
Shares remaining authorized for repurchase (in shares)se Program, Remaining Number of Shares Authorized to be Repurchased			971,524	971,524
RSU's and PSU's
Class of Stock [Line Items]
Share based compensation expense			$ 875,000	$ 2,000,000.0
Maximum
Class of Stock [Line Items]
Shelf registration, shares registered (in shares)			1,500,000	1,500,000
Maximum | The 2015 Program
Class of Stock [Line Items]
Stock repurchase program, authorized amount							$ 40,000,000
Maximum | The 2019 Program
Class of Stock [Line Items]
Stock repurchase program, authorized amount			$ 43,900,000	$ 43,900,000
Subsequent Event
Class of Stock [Line Items]
Dividends declared per share (in dollars per share)	$ 0.26