Restatement of Previously Issued Financial Statements - Statements of Equity (Details) - USD ($) $ / shares in Units, $ in Thousands		3 Months Ended
		Mar. 31, 2020	Mar. 31, 2019
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Balance, beginning of period	[1]	$ 36,266	$ 56,818
Net income (loss)	[1]	21,512	(3,385)
Issuance of common stock, net of conversions	[1]	0	1
Share-based compensation expense	[1]	554	807
Cash dividends	[1]	(1,226)	(1,177)
Other comprehensive loss	[1]	(4,015)	(192)
Reclassification adjustment to net income	[1]	305	86
Balance, end of period	[1]	$ 53,396	$ 52,958
Cash Dividends on Class A Common and Class B Common per share (in usd per share)		$ 0.09	$ 0.085
As Previously Reported
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Balance, beginning of period			$ 65,438
Net income (loss)			(1,761)
Issuance of common stock, net of conversions			1
Share-based compensation expense			807
Other comprehensive loss			(221)
Reclassification adjustment to net income			(8)
Balance, end of period			$ 63,079
Cash Dividends on Class A Common and Class B Common per share (in usd per share)			$ 0.085
Restatement Impacts
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Balance, beginning of period			$ (8,620)
Net income (loss)			(1,624)
Other comprehensive loss			29
Reclassification adjustment to net income			94
Balance, end of period			$ (10,121)
Cash Dividends on Class A Common and Class B Common per share (in usd per share)			$ 0.085
Capital in Excess of Par Value
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Balance, beginning of period		$ 54,509	$ 51,714
Issuance of common stock, net of conversions		(1)	(1)
Share-based compensation expense		554	807
Balance, end of period		55,062	52,520
Capital in Excess of Par Value | As Previously Reported
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Balance, beginning of period			51,714
Issuance of common stock, net of conversions			(1)
Share-based compensation expense			807
Balance, end of period			52,520
Capital in Excess of Par Value | Restatement Impacts
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Balance, beginning of period			0
Balance, end of period			0
Treasury Stock
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Balance, beginning of period		(5,960)	0
Balance, end of period		(5,960)	0
Retained Earnings (1)
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Balance, beginning of period	[1]	3,710	22,068
Net income (loss)	[1]	21,512	(3,385)
Cash dividends	[1]	(1,226)	(1,177)
Balance, end of period	[1]	23,996	17,506
Retained Earnings (1) | As Previously Reported
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Balance, beginning of period			30,897
Net income (loss)			(1,761)
Balance, end of period			27,959
Retained Earnings (1) | Restatement Impacts
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Balance, beginning of period			(8,829)
Net income (loss)			(1,624)
Balance, end of period			(10,453)
Accumulated Other Comprehensive Income (Loss) (1)
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Balance, beginning of period	[1]	(16,132)	(17,101)
Other comprehensive loss	[1]	(4,015)	(192)
Reclassification adjustment to net income	[1]	305	86
Balance, end of period	[1]	(19,842)	(17,207)
Accumulated Other Comprehensive Income (Loss) (1) | As Previously Reported
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Balance, beginning of period			(17,310)
Other comprehensive loss			(221)
Reclassification adjustment to net income			(8)
Balance, end of period			(17,539)
Accumulated Other Comprehensive Income (Loss) (1) | Restatement Impacts
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Balance, beginning of period			209
Other comprehensive loss			29
Reclassification adjustment to net income			94
Balance, end of period			332
Class A Common Stock | Common Stock
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Balance, beginning of period		98	93
Issuance of common stock, net of conversions		1	2
Balance, end of period		99	95
Class A Common Stock | Common Stock | As Previously Reported
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Balance, beginning of period			93
Issuance of common stock, net of conversions			2
Balance, end of period			95
Class A Common Stock | Common Stock | Restatement Impacts
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Balance, beginning of period			0
Balance, end of period			0
Class B Common Stock | Common Stock
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Balance, beginning of period		41	44
Share-based compensation expense			0
Balance, end of period		$ 41	44
Class B Common Stock | Common Stock | As Previously Reported
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Balance, beginning of period			44
Balance, end of period			44
Class B Common Stock | Common Stock | Restatement Impacts
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Balance, beginning of period			0
Balance, end of period			0
Common Class A and B
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Cash dividends			(1,177)
Common Class A and B | As Previously Reported
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Cash dividends			(1,177)
Common Class A and B | Retained Earnings (1)
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Cash dividends			(1,177)
Common Class A and B | Retained Earnings (1) | As Previously Reported
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Cash dividends			$ (1,177)

[1] As Restated