Segment and Geographical Information - Geographical Operating Information (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
Revenues from External Customers and Long-Lived Assets [Line Items]
Sales	$ 137,111	$ 151,657	$ 115,801	$ 140,305	$ 147,360	$ 149,829	$ 163,145	$ 143,187	$ 544,874	$ 603,521	$ 659,718
Operating Income									77,784	98,289	108,660
Identifiable Assets	2,319,263				2,453,115				2,319,263	2,453,115
New Zealand JV
Revenues from External Customers and Long-Lived Assets [Line Items]
Operating income gain from consolidation of New Zealand JV											16,200
Geographic Operating Information | United States
Revenues from External Customers and Long-Lived Assets [Line Items]
Sales									302,074	317,422	380,575
Operating Income									73,749	87,116	80,158
Identifiable Assets	1,826,462				1,884,585				1,826,462	1,884,585
Geographic Operating Information | New Zealand
Revenues from External Customers and Long-Lived Assets [Line Items]
Sales									242,800	286,099	279,143
Operating Income									4,035	11,173	$ 28,502
Identifiable Assets	$ 492,801				$ 568,530				$ 492,801	$ 568,530