Amount, before unamortized (discount) premium and debt issuance costs, of long-term debt. Includes, but is not limited to, notes payable, bonds payable, commercial loans, mortgage loans, convertible debt, subordinated debt and other types of debt.

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Fair value portion of debt instrument payable, including, but not limited to, notes payable and loans payable.

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Contractual interest rate for funds borrowed, under the debt agreement.

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Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

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Date the credit facility terminates, in CCYY-MM-DD format.

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The fair value amount of long-term debt whether such amount is presented as a separate caption or as a parenthetical disclosure. Additionally, this element may be used in connection with the fair value disclosures required in the footnote disclosures to the financial statements. The element may be used in both the balance sheet and disclosure in the same submission.

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The carrying value as of the balance sheet date of the noncurrent portion of long-term obligations drawn from a line of credit, which is a bank's commitment to make loans up to a specific amount. Examples of items that might be included in the application of this element may consist of letters of credit, standby letters of credit, and revolving credit arrangements, under which borrowings can be made up to a maximum amount as of any point in time conditional on satisfaction of specified terms before, as of and after the date of drawdowns on the line. Includes short-term obligations that would normally be classified as current liabilities but for which (a) postbalance sheet date issuance of a long term obligation to refinance the short term obligation on a long term basis, or (b) the enterprise has entered into a financing agreement that clearly permits the enterprise to refinance the short-term obligation on a long term basis and the following conditions are met (1) the agreement does not expire within 1 year and is not cancelable by the lender except for violation of an objectively determinable provision, (2) no violation exists at the BS date, and (3) the lender has entered into the financing agreement is expected to be financially capable of honoring the agreement.

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The cash inflow from a debt initially having maturity due after one year or beyond the operating cycle, if longer.

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Identify the stated interest rate per the agreement, for example, leasing and debt arrangements between related parties.

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The cash outflow during the period from the repayment of aggregate short-term and long-term debt. Excludes payment of capital lease obligations.

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Principal due to Timberland Venture

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Maximum borrowing capacity under the term loan without consideration of any current restrictions on the amount that could be borrowed or the amounts currently outstanding under the term loan.

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Unamortized discount, capitalized debt expense and fair value adjustment

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LONG-TERM DEBT - Additional Information (Details) - USD ($) $ in Millions	3 Months Ended		12 Months Ended
	Dec. 31, 2017	Sep. 30, 2017	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015	Feb. 19, 2016
Debt Instrument [Line Items]
Line of Credit Facility, Expiration Date			Mar. 31, 2022
Long-term Debt, Gross	$ 6,008		$ 6,008	$ 6,628
Proceeds from issuance of long-term debt		$ 225	225	1,698	$ 0
Unamortized discounts, capitalized debt expense and fair value adjustments	36		36
Variable rate term loan credit facility matures 2020
Debt Instrument [Line Items]
Term loan credit facility	$ 0		$ 0	550
Line of Credit Facility, Expiration Date			Dec. 31, 2020
Repayments of debt		550
Interest rate, stated	0.00%		0.00%
Variable rate term loan credit facility matures 2026
Debt Instrument [Line Items]
Term loan credit facility	$ 225		$ 225	$ 0
Line of Credit Facility, Expiration Date			Dec. 31, 2026
Interest rate, stated	3.152%		3.152%
Plum Creek
Debt Instrument [Line Items]
Repayments of debt			$ 720
Senior Note due 2021 [Member]
Debt Instrument [Line Items]
Long-term Debt, Gross	$ 569		$ 569
Interest rate, stated	4.70%		4.70%
Senior Note due 2021 [Member] \| Plum Creek
Debt Instrument [Line Items]
Long-term debt, fair value						$ 614
Senior Note due 2023 [Member]
Debt Instrument [Line Items]
Long-term Debt, Gross	$ 325		$ 325
Interest rate, stated	3.25%		3.25%
Senior Note due 2023 [Member] \| Plum Creek
Debt Instrument [Line Items]
Long-term debt, fair value						324
Installment Note Payable [Member]
Debt Instrument [Line Items]
Long-term Debt, Gross	$ 860		$ 860
Interest rate, stated	5.207%		5.207%
Installment Note Payable [Member] \| Plum Creek
Debt Instrument [Line Items]
Long-term debt, fair value						893
Note Payable to Timberland Venture [Member]
Debt Instrument [Line Items]
Principal on note payable due to Timberland Venture	$ 783		$ 783
Annual interest rate on note payable			7.375%
Note Payable to Timberland Venture [Member] \| Plum Creek
Debt Instrument [Line Items]
Note payable to Timberland Venture, fair value						$ 838
Term Loan due August 2017 [Member]
Debt Instrument [Line Items]
Repayments of debt	600
Term loan, maximum borrowing capacity	600		$ 600
Term Loan due September 2017 [Member]
Debt Instrument [Line Items]
Repayments of debt	1,100
Term loan, maximum borrowing capacity	$ 1,900		$ 1,900
Variable rate term loan credit facility matures 2020 \| Variable rate term loan credit facility matures 2020
Debt Instrument [Line Items]
Repayments of debt		225
Cash and Cash Equivalents \| Variable rate term loan credit facility matures 2020
Debt Instrument [Line Items]
Repayments of debt		$ 325