Financial Instruments and Concentration of Risk (Effect Of Derivatives on the Consolidated Statement of Operations) (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2014		Dec. 31, 2013		Dec. 31, 2012
Derivatives designated as hedging instruments [Member] | Interest rate contracts [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Net gain (loss) recognized in income	$ 979		$ 960		$ 868
Derivatives designated as hedging instruments [Member] | Interest expense [Member] | Interest rate contracts [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Realized gain (loss) on hedging instrument/derivative	979	[1]	960	[1]	868	[1]
Derivatives not designated as hedging instruments [Member] | Lumber contracts [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Net gain (loss) recognized in income	0		0		(876)
Derivatives not designated as hedging instruments [Member] | Cost of goods sold [Member] | Lumber contracts [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Unrealized gain (loss) on derivative	0		0		(480)
Realized gain (loss) on hedging instrument/derivative	$ 0		$ 0		$ (396)

[1] 1 Realized gain on hedging instrument consists of net cash settlements and interest accruals on the interest rate swaps during the period.