Fair Value Measurements Variable Interest Entity (Details) (USD $)	9 Months Ended
	Sep. 30, 2012		Dec. 31, 2004
Variable Interest Entity [Line Items]
Type of Entity	bankruptcy-remote, limited liability subsidiary
Date involvement began	2004
Amount of installment note and letter of credit contributed to special purpose entity			$ 25,000,000
Amount of cash received			22,600,000
Interest cash payments received, net	immaterial cash payments
Classification of carrying amount of interest	"Other Assets"
Recorded liability for performance obligation	de minimus guarantee liability
Maximum exposure	28,373,000
Type of financial obligation	make-whole agreement
Cash to be received upon maturity	2,600,000
Variable Interest Entity, Not Primary Beneficiary [Member]
Variable Interest Entity [Line Items]
Amount of notes issued by special purpose entity			22,600,000
Term of notes issued by special purpose entity			15-year
Variable interest entity investment	2,600,000
Maturity date of notes issued by special purpose entity	2019
Financial Guarantee [Member]
Variable Interest Entity [Line Items]
Recorded liability for performance obligation	de minimus liability
Maximum exposure	$ 2,254,000	[1]

[1] In conjunction with a timberland sale and note monetization in the first quarter of 2004, the Company issued a make-whole agreement pursuant to which it guaranteed $2.3 million of obligations of a special-purpose entity that was established to complete the monetization. At September 30, 2012, the Company has a de minimus liability to reflect the fair market value of its obligation to perform under the make-whole agreement.