Segment Information - Geographic Distribution and Net Sales by Product (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Net sales and long-lived assets by geographical area
Net Sales	$ 184,764	$ 216,139	$ 216,665	$ 176,491	$ 166,630	$ 209,320	$ 207,893	$ 168,305	$ 794,059	$ 752,148	$ 705,322
Long-Lived Assets	219,086				210,775				219,086	210,775	$ 212,122
Largest customer | Net sales
Net sales and long-lived assets by geographical area
Percentage of net sales attributable to largest customer											10.00%
Wood Construction
Net sales and long-lived assets by geographical area
Net Sales									674,274	636,003	$ 596,837
Concrete Construction
Net sales and long-lived assets by geographical area
Net Sales									119,481	115,921	108,295
Other
Net sales and long-lived assets by geographical area
Net Sales									304	224	190
United States
Net sales and long-lived assets by geographical area
Net Sales									639,443	572,112	531,019
Long-Lived Assets	171,367				158,161				171,367	158,161	152,644
Canada
Net sales and long-lived assets by geographical area
Net Sales									36,122	40,996	41,626
Long-Lived Assets	4,275				5,195				4,275	5,195	5,763
Denmark
Net sales and long-lived assets by geographical area
Net Sales									14,987	15,121	14,993
Long-Lived Assets	1,381				1,518				1,381	1,518	1,907
United Kingdom
Net sales and long-lived assets by geographical area
Net Sales									22,924	24,893	21,852
Long-Lived Assets	1,357				1,377				1,357	1,377	1,249
France
Net sales and long-lived assets by geographical area
Net Sales									31,147	37,312	36,708
Long-Lived Assets	8,621				8,145				8,621	8,145	9,302
Germany
Net sales and long-lived assets by geographical area
Net Sales									19,974	27,202	26,058
Long-Lived Assets	13,358				15,379				13,358	15,379	17,446
Switzerland
Net sales and long-lived assets by geographical area
Net Sales									5,538	4,960	5,977
Long-Lived Assets	9,071				9,506				9,071	9,506	11,649
Poland
Net sales and long-lived assets by geographical area
Net Sales									6,417	7,491	5,982
Long-Lived Assets	893				1,071				893	1,071	692
The Netherlands
Net sales and long-lived assets by geographical area
Net Sales									4,773	4,539	4,306
Long-Lived Assets	15				30				15	30	63
Portugal
Net sales and long-lived assets by geographical area
Net Sales									1,580	806	804
Long-Lived Assets	332				472				332	472	688
China/Hong Kong
Net sales and long-lived assets by geographical area
Net Sales									4,097	9,646	9,802
Long-Lived Assets	7,510				8,966				7,510	8,966	9,499
Australia
Net sales and long-lived assets by geographical area
Net Sales									3,121	3,245	3,289
Long-Lived Assets	274				267				274	267	356
New Zealand
Net sales and long-lived assets by geographical area
Net Sales									2,154	2,237	1,701
Long-Lived Assets	142				82				142	82	125
Other countries
Net sales and long-lived assets by geographical area
Net Sales									1,782	1,588	1,205
Long-Lived Assets	$ 490				$ 606				$ 490	$ 606	$ 739