Gains on Dispositions of Plant, Equipment and Timberlands, Net - Summary for Sale of Timberlands and Other Assets (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2014	Jun. 30, 2013	Jun. 30, 2014	Jun. 30, 2013
Property, Plant and Equipment [Line Items]
Proceeds			$ 2,360	$ 92
Gain	1,482	19	2,291	92
Timberlands [Member]
Property, Plant and Equipment [Line Items]
Acres			935
Proceeds			2,355
Gain			2,290
Other [Member]
Property, Plant and Equipment [Line Items]
Proceeds			5	92
Gain			$ 1	$ 92