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	(13,411)	(238)	(13,649)
Other comprehensive income (loss)	0	0	(7,780)	0	0	0	(7,780)
Change in ownership percentage of subsidiary	0	0	0	0	0	(120)	(120)
Dividends declared	0		0	0	(7,157)	0	(7,149)
Dividends declared		8
Stock buy-back program	$ (59)	(13,855)	0	0	0	0	(13,914)
Stock buy-back program (in shares)	(296)
Stock-based compensation	$ 0	2,301	0	0	0	0	2,301
Stock-based compensation (in shares)	0
RSU vesting	$ 5	(5)	0	0	0	0	0
RSU vesting (in shares)	24
Withholding tax paid upon vesting of RSUs	$ 0	(432)	0	0	0	0	(432)
SERP transactions, net	0	218	0	28	0	0	246
Other	0	0	0	0	(1)	7	6
Balance at Sep. 30, 2018	$ 4,560	130,166	(32,023)	(1,932)	544,761	742	646,274
Balance (in shares) at Sep. 30, 2018	22,798
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
Net income (loss)	$ 0	0	0	0	6,995	(92)	6,903
Other comprehensive income (loss)	0	0	(1,536)	0	0	0	(1,536)
Change in ownership percentage of subsidiary	0	0	0	0	0	(11)	(11)
Dividends declared	0		0	0	(2,534)	0	(2,531)
Dividends declared		3
Stock buy-back program	$ (59)	(13,855)	0	0	0	0	(13,914)
Stock buy-back program (in shares)	(296)
Stock-based compensation	$ 0	411	0	0	0	0	411
Stock-based compensation (in shares)	0
SERP transactions, net	$ 0	11	0	(44)	0	0	(33)
Other	0	0	0	0	0	4	4
Balance at Sep. 30, 2018	$ 4,560	130,166	(32,023)	(1,932)	544,761	742	646,274
Balance (in shares) at Sep. 30, 2018	22,798
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 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
Cumulative impact of No. ASU 2018-02 | ASU 2018-02 [Member]	$ 0	0	(721)	0	721	0	0
Net income (loss)	0	0	0	0	40,662	(127)	40,535
Other comprehensive income (loss)	0	0	(2,631)	0	0	(40)	(2,671)
Change in ownership percentage of subsidiary	0	0	0	0	0	(9)	(9)
Dividends declared	0		0	0	(7,445)	0	(7,436)
Dividends declared		9
Stock-based compensation	$ 0	2,014	0	0	0	0	2,014
Stock-based compensation (in shares)	2
RSU vesting	$ 6	(6)	0	0	0	0	0
RSU vesting (in shares)	31
Withholding tax paid upon vesting of RSUs	$ 0	(312)	0	0	0	0	(312)
SERP transactions, net	0	67	0	125	0	0	192
Other	0	0	(8)	0	(1)	(10)	(19)
Balance at Sep. 30, 2019	$ 4,509	122,373	(37,243)	(1,761)	529,182	524	617,584
Balance (in shares) at Sep. 30, 2019	22,546
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
Net income (loss)	$ 0	0	0	0	3,010	(55)	2,955
Other comprehensive income (loss)	0	0	(3,474)	0	0	(50)	(3,524)
Dividends declared	0		0	0	(2,483)	0	(2,480)
Dividends declared		3
Stock-based compensation	$ 0	241	0	0	0	0	241
Stock-based compensation (in shares)	0
RSU vesting	$ 3	(3)	0	0	0	0	0
RSU vesting (in shares)	15
Withholding tax paid upon vesting of RSUs	$ 0	(152)	0	0	0	0	(152)
SERP transactions, net	0	(1)	0	(45)	0	0	(46)
Other	0	0	(18)	0	0	0	(18)
Balance at Sep. 30, 2019	$ 4,509	$ 122,373	$ (37,243)	$ (1,761)	$ 529,182	$ 524	$ 617,584
Balance (in shares) at Sep. 30, 2019	22,546