Condensed Consolidated Statements of Equity (unaudited) - USD ($) shares in Thousands, $ in Thousands	Common Stock [Member]	Additional Paid-in-Capital [Member]	Accumulated Other Comprehensive Loss [Member]	Company Shares Held by SERP [Member]	Retained Earnings [Member]	Non-controlling Interest [Member]	Total
Balance at Dec. 31, 2017	$ 4,614	$ 141,931	$ (24,243)	$ (1,960)	$ 565,330	$ 1,093	$ 686,765
Balance (in shares) at Dec. 31, 2017	23,070
Net income (loss)	$ 0	0	0	0	(20,407)	(145)	(20,552)
Other comprehensive income (loss)	0	0	(6,244)	0	0	0	(6,244)
Change in ownership percentage of subsidiary	0	0	0	0	0	(109)	(109)
Dividends declared	0		0	0	(4,623)	0	(4,618)
Dividends declared		5
Stock-based compensation	$ 0	1,890	0	0	0	0	1,890
Stock-based compensation (in shares)	0
Stock issued under incentive plans	$ 5	(5)	0	0	0	0	0
Stock issued under incentive plans (in shares)	24
Withholding tax paid upon vesting of RSUs	$ 0	(432)	0	0	0	0	(432)
SERP transactions, net	0	207	0	72	0	0	279
Other	0	0	0	0	0	2	2
Balance at Jun. 30, 2018	$ 4,619	143,596	(30,487)	(1,888)	540,300	841	656,981
Balance (in shares) at Jun. 30, 2018	23,094
Balance at Mar. 31, 2018	$ 4,617	143,355	(22,466)	(1,791)	583,286	1,075	708,076
Balance (in shares) at Mar. 31, 2018	23,087
Net income (loss)	$ 0	0	0	0	(40,674)	(94)	(40,768)
Other comprehensive income (loss)	0	0	(8,021)	0	0	0	(8,021)
Change in ownership percentage of subsidiary	0	0	0	0	0	(66)	(66)
Dividends declared	0		0	0	(2,312)	0	(2,310)
Dividends declared		2
Stock-based compensation	$ 0	309	0	0	0	0	309
Stock-based compensation (in shares)	0
Stock issued under incentive plans	$ 2	(2)	0	0	0	0	0
Stock issued under incentive plans (in shares)	7
Withholding tax paid upon vesting of RSUs	$ 0	(68)	0	0	0	0	(68)
SERP transactions, net	0	0	0	(97)	0	0	(97)
Other	0	0	0	0	0	(74)	(74)
Balance at Jun. 30, 2018	$ 4,619	143,596	(30,487)	(1,888)	540,300	841	656,981
Balance (in shares) at Jun. 30, 2018	23,094
Cumulative impact of No. ASU 2018-02 | ASU 2018-02 [Member]	$ 0	0	(721)	0	721	0	0
Balance at Dec. 31, 2018	$ 4,503	120,601	(33,883)	(1,886)	495,245	710	585,290
Balance (in shares) at Dec. 31, 2018	22,513
Net income (loss)	$ 0	0	0	0	37,651	(72)	37,579
Other comprehensive income (loss)	0	0	853	0	0	0	853
Change in ownership percentage of subsidiary	0	0	0	0	0	(9)	(9)
Dividends declared	0		0	0	(4,962)	0	(4,956)
Dividends declared		6
Stock-based compensation	$ 0	1,773	0	0	0	0	1,773
Stock-based compensation (in shares)	2
RSU vesting	$ 3	(3)	0	0	0	0	0
RSU vesting (in shares)	16
Withholding tax paid upon vesting of RSUs	$ 0	(160)	0	0	0	0	(160)
SERP transactions, net	0	68	0	170	0	0	238
Balance at Jun. 30, 2019	$ 4,506	122,285	(33,751)	(1,716)	528,655	629	620,608
Balance (in shares) at Jun. 30, 2019	22,531
Balance at Mar. 31, 2019	$ 4,505	121,665	(33,641)	(1,669)	507,759	647	599,266
Balance (in shares) at Mar. 31, 2019	22,523
Net income (loss)	$ 0	0	0	0	23,377	(16)	23,361
Other comprehensive income (loss)	0	0	(110)	0	0	0	(110)
Change in ownership percentage of subsidiary	0	0	0	0	0	(9)	(9)
Dividends declared	0		0	0	(2,481)	0	(2,478)
Dividends declared		3
Stock-based compensation	$ 0	596	0	0	0	0	596
Stock-based compensation (in shares)	1
RSU vesting	$ 1	(1)	0	0	0	0	0
RSU vesting (in shares)	7
SERP transactions, net	$ 0	22	0	(47)	0	0	(25)
Other	0	0	0	0	0	7	7
Balance at Jun. 30, 2019	$ 4,506	$ 122,285	$ (33,751)	$ (1,716)	$ 528,655	$ 629	$ 620,608
Balance (in shares) at Jun. 30, 2019	22,531