Stock Repurchase Program (Details Textual) - USD ($) $ in Millions				3 Months Ended
	Mar. 31, 2020	Dec. 17, 2019	Dec. 18, 2018	Mar. 31, 2020	Mar. 17, 2020	Dec. 31, 2019
Equity Class Of Treasury Stock [Line Items]
Common stock, shares outstanding	4,227,755			4,227,755		4,323,822
Stock repurchase program, remaining authorized amount	$ 2			$ 2
Stock Repurchase Program on December 18, 2018
Equity Class Of Treasury Stock [Line Items]
Percentage of shares authorized to be repurchased to common stock outstanding			6.90%
Common stock, shares outstanding			4,349,624
Stock repurchase program expiration date				Dec. 31, 2019
Stock repurchase program, shares repurchased				54,000
Stock Repurchase Program on December 18, 2018 | Maximum
Equity Class Of Treasury Stock [Line Items]
Shares authorized to be repurchased			300,000
Stock Repurchase Program on March 17, 2020
Equity Class Of Treasury Stock [Line Items]
Shares authorized to be repurchased					300,000
Stock repurchase program expiration date				Dec. 31, 2020
Stock repurchase program, shares repurchased	146,318
Increase in number of shares authorized to be repurchased					100,000
Stock Repurchase Program on March 17, 2020 | Maximum
Equity Class Of Treasury Stock [Line Items]
Shares authorized to be repurchased		300,000
Stock Repurchase Program on December 17, 2019
Equity Class Of Treasury Stock [Line Items]
Percentage of shares authorized to be repurchased to common stock outstanding		4.60%
Common stock, shares outstanding		4,323,822
Stock repurchase program, shares repurchased				200,000