Condensed Consolidating Financial Statements - Condensed Consolidating Balance Sheet (Detail) - USD ($) $ in Thousands	Jun. 30, 2016	Dec. 31, 2015	Jun. 30, 2015	Dec. 31, 2014
Assets
Cash and cash equivalents	$ 58,532	$ 105,304	$ 65,762	$ 99,837
Other current assets	466,053	447,063
Plant, equipment and timberlands, net	748,036	698,864
Other assets	252,563	249,185
Total assets	1,525,184	1,500,416
Liabilities and Shareholders' Equity
Current liabilities	311,393	304,320
Long-term debt	358,366	353,296
Deferred income taxes	75,155	76,458
Other long-term liabilities	104,047	103,095
Total liabilities	848,961	837,169
Shareholders' equity	676,223	663,247
Total liabilities and shareholders' equity	1,525,184	1,500,416
Adjustments/ Eliminations [Member]
Assets
Other current assets	(262,714)	(230,509)
Investments in subsidiaries	(1,318,596)	(1,244,566)
Total assets	(1,581,310)	(1,475,075)
Liabilities and Shareholders' Equity
Current liabilities	(262,714)	(230,523)
Total liabilities	(262,714)	(230,523)
Shareholders' equity	(1,318,596)	(1,244,552)
Total liabilities and shareholders' equity	(1,581,310)	(1,475,075)
Parent Company [Member]
Assets
Cash and cash equivalents	6,512	59,130	34,316	42,208
Other current assets	207,168	199,690
Plant, equipment and timberlands, net	329,041	286,334
Investments in subsidiaries	783,479	737,450
Other assets	112,876	106,586
Total assets	1,439,076	1,389,190
Liabilities and Shareholders' Equity
Current liabilities	401,540	363,037
Long-term debt	247,381	247,075
Deferred income taxes	26,905	28,561
Other long-term liabilities	87,027	87,270
Total liabilities	762,853	725,943
Shareholders' equity	676,223	663,247
Total liabilities and shareholders' equity	1,439,076	1,389,190
Guarantors [Member]
Assets
Cash and cash equivalents	2,545	465	392	509
Other current assets	255,574	238,515
Plant, equipment and timberlands, net	18,507	1,114
Investments in subsidiaries	535,117	507,116
Total assets	811,743	747,210
Liabilities and Shareholders' Equity
Current liabilities	28,180	9,725
Deferred income taxes	(229)	(79)
Other long-term liabilities	313
Total liabilities	28,264	9,646
Shareholders' equity	783,479	737,564
Total liabilities and shareholders' equity	811,743	747,210
Non Guarantors [Member]
Assets
Cash and cash equivalents	49,475	45,709	$ 31,054	$ 57,120
Other current assets	266,025	239,367
Plant, equipment and timberlands, net	400,488	411,416
Other assets	139,687	142,599
Total assets	855,675	839,091
Liabilities and Shareholders' Equity
Current liabilities	144,387	162,081
Long-term debt	110,985	106,221
Deferred income taxes	48,479	47,976
Other long-term liabilities	16,707	15,825
Total liabilities	320,558	332,103
Shareholders' equity	535,117	506,988
Total liabilities and shareholders' equity	$ 855,675	$ 839,091