Consolidated Statements of Shareholders' Equity - USD ($) $ in Thousands	Total	Common Stock [Member]	Additional Paid-in Capital [Member]	Retained Earnings [Member]	Accumulated Other Comprehensive Loss [Member]	Noncontrolling Interest [Member]
Beginning Balance at Dec. 31, 2013	$ 234,995	$ 10,373	$ 125,852	$ 144,635	$ (45,865)	$ 0
Stock-based compensation	835		835
Comprehensive (loss) income:
Net (loss) income	(1,187)			(1,187)
Other comprehensive (loss) income	(22,888)				(22,888)
Comprehensive (loss) income	(24,075)
Issuance of common stock including excess tax benefits of $60,$0,$0 for 2014, 2015 and 2016	892	53	839
Cash dividends ($0.72, $0.72 and $0.36 per share for 2014, 2015 and 2016)	(7,499)			(7,499)
Ending Balance at Dec. 31, 2014	205,148	10,426	127,526	135,949	(68,753)	0
Stock-based compensation	1,103		1,103
Comprehensive (loss) income:
Net (loss) income	1,373			1,373
Other comprehensive (loss) income	11,154				11,154
Comprehensive (loss) income	12,527
Issuance of common stock including excess tax benefits of $60,$0,$0 for 2014, 2015 and 2016	225	14	211
Cash dividends ($0.72, $0.72 and $0.36 per share for 2014, 2015 and 2016)	(7,580)			(7,580)
Ending Balance at Dec. 31, 2015	211,423	10,440	128,840	129,742	(57,599)	0
Noncontrolling interest associated with Åkers acquisition (Note 2)	2,019					2,019
Stock-based compensation	1,482		1,482
Comprehensive (loss) income:
Net (loss) income	(79,809)			(79,820)		11
Other comprehensive (loss) income	(3,400)				(3,286)	(114)
Comprehensive (loss) income	(83,209)					(103)
Issuance of common stock including excess tax benefits of $60,$0,$0 for 2014, 2015 and 2016	22,598	1,831	20,767
Cash dividends ($0.72, $0.72 and $0.36 per share for 2014, 2015 and 2016)	(4,479)			(4,479)
Ending Balance at Dec. 31, 2016	$ 147,918	$ 12,271	$ 151,089	$ 45,443	$ (60,885)	$ 1,916