Condensed Consolidating Financial Statements - Condensed Consolidating Balance Sheet (Detail) - USD ($) $ in Thousands	Jun. 30, 2017	Dec. 31, 2016	Jun. 30, 2016	Dec. 31, 2015
Assets
Cash and cash equivalents	$ 69,442	$ 55,444	$ 58,532	$ 105,304
Other current assets	470,767	438,815
Plant, equipment and timberlands, net	838,007	775,898
Other assets	263,565	251,102
Total assets	1,641,781	1,521,259
Liabilities and Shareholders' Equity
Current liabilities	339,764	323,011
Long-term debt	431,494	363,647
Deferred income taxes	60,715	54,995
Other long-term liabilities	124,776	125,780
Total liabilities	956,749	867,433
Shareholders’ equity	685,032	653,826
Total liabilities and shareholders’ equity	1,641,781	1,521,259
Parent Company [Member]
Assets
Cash and cash equivalents	8,587	5,082	6,512	59,130
Other current assets	219,123	206,002
Plant, equipment and timberlands, net	384,846	360,521
Investments in subsidiaries	851,050	789,565
Other assets	127,334	123,010
Total assets	1,590,940	1,484,180
Liabilities and Shareholders' Equity
Current liabilities	447,573	426,628
Long-term debt	338,991	283,686
Deferred income taxes	13,083	10,221
Other long-term liabilities	106,263	109,819
Total liabilities	905,910	830,354
Shareholders’ equity	685,030	653,826
Total liabilities and shareholders’ equity	1,590,940	1,484,180
Guarantors [Member]
Assets
Cash and cash equivalents	3,080	1,461	2,545	465
Other current assets	278,908	256,289
Plant, equipment and timberlands, net	58,075	31,455
Investments in subsidiaries	601,864	540,029
Total assets	941,927	829,234
Liabilities and Shareholders' Equity
Current liabilities	52,294	26,085
Long-term debt	39,000	14,000
Deferred income taxes	(729)	(729)
Other long-term liabilities	312	313
Total liabilities	90,877	39,669
Shareholders’ equity	851,050	789,565
Total liabilities and shareholders’ equity	941,927	829,234
Non Guarantors [Member]
Assets
Cash and cash equivalents	57,775	48,901	$ 49,475	$ 45,709
Other current assets	277,622	242,187
Plant, equipment and timberlands, net	395,086	383,922
Other assets	136,231	128,092
Total assets	866,714	803,102
Liabilities and Shareholders' Equity
Current liabilities	144,785	135,961
Long-term debt	53,503	65,961
Deferred income taxes	48,361	45,503
Other long-term liabilities	18,201	15,648
Total liabilities	264,850	263,073
Shareholders’ equity	601,864	540,029
Total liabilities and shareholders’ equity	866,714	803,102
Adjustments/ Eliminations [Member]
Assets
Other current assets	(304,886)	(265,663)
Investments in subsidiaries	(1,452,914)	(1,329,594)
Total assets	(1,757,800)	(1,595,257)
Liabilities and Shareholders' Equity
Current liabilities	(304,888)	(265,663)
Total liabilities	(304,888)	(265,663)
Shareholders’ equity	(1,452,912)	(1,329,594)
Total liabilities and shareholders’ equity	$ (1,757,800)	$ (1,595,257)