SEGMENT AND GEOGRAPHIC REGION INFORMATION (Details) - USD ($) $ in Thousands	3 Months Ended										12 Months Ended
	Dec. 31, 2017	Jun. 30, 2017	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Financial information of segments
SALES			$ 316,122	$ 291,256	$ 268,694	$ 256,820	$ 292,866	$ 292,097	$ 294,700	$ 284,629	$ 1,132,892	$ 1,164,292	$ 1,104,442
OPERATING PROFIT											87,969	136,308	101,110
Write-off of property, plant, and equipment	$ 16,300										16,306	0	0
Pension settlement charges	$ 2,200
Restructuring charges		$ 2,200
Operating Segments
Financial information of segments
SALES											1,132,892	1,164,292	1,104,442
INTERSEGMENT SALES											12,272	16,015	16,182
DEPRECIATION AND AMORTIZATION											26,703	23,025	21,279
CAPITAL EXPENDITURES											39,677	42,695	31,947
Corporate
Financial information of segments
SALES											0	0	0
INTERSEGMENT SALES											0	0	0
DEPRECIATION AND AMORTIZATION											0	0	0
OPERATING PROFIT											(13,684)	(16,929)	(19,938)
CAPITAL EXPENDITURES											0	0	0
Office
Financial information of segments
Write-off of property, plant, and equipment											16,300
Pension settlement charges											2,200
Restructuring charges											2,200
Office | Operating Segments
Financial information of segments
SALES											682,936	731,327	686,943
INTERSEGMENT SALES											1,331	1,877	1,640
DEPRECIATION AND AMORTIZATION											19,177	16,284	14,945
OPERATING PROFIT											25,894	73,871	55,823
CAPITAL EXPENDITURES											32,413	35,072	27,058
Studio | Operating Segments
Financial information of segments
SALES											340,995	323,431	303,838
INTERSEGMENT SALES											5,572	5,788	6,184
DEPRECIATION AND AMORTIZATION											6,776	5,936	5,565
OPERATING PROFIT											51,136	53,413	47,952
CAPITAL EXPENDITURES											7,061	6,819	4,241
Coverings | Operating Segments
Financial information of segments
SALES											108,961	109,534	113,661
INTERSEGMENT SALES											5,369	8,350	8,358
DEPRECIATION AND AMORTIZATION											750	805	769
OPERATING PROFIT											24,623	25,953	17,273
CAPITAL EXPENDITURES											$ 203	$ 804	$ 648