Number of common shares reserved for future issuance related to deferred compensation arrangements with individuals.

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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.

+ References

No definition available.

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- Definition

Unrecognized cost of unvested share-based compensation awards.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (i)
-URI http://asc.fasb.org/extlink&oid=96867065&loc=d3e5070-113901

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- Definition

Weighted average period over which unrecognized compensation is expected to be recognized for equity-based compensation plans, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

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- Definition

Amount of tax benefit from exercise of stock options granted under share-based compensation arrangement.

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Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 50
-Paragraph 2A
-Subparagraph (a)
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- Definition

The aggregate amount of noncash, equity-based employee remuneration. This may include the value of stock or unit options, amortization of restricted stock or units, and adjustment for officers' compensation. As noncash, this element is an add back when calculating net cash generated by operating activities using the indirect method.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 28
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=98514028&loc=d3e3602-108585

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Additional share-based compensation cost recognized as a result of an occurrence of an event that accelerates its recognition.

+ References

No definition available.

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- Definition

Period which an employee's right to exercise an award is no longer contingent on satisfaction of either a service condition, market condition or a performance condition, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

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Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (a)(1)
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- Definition

The weighted average fair value at grant date for nonvested equity-based awards issued during the period on other than stock (or unit) option plans (for example, phantom stock or unit plan, stock or unit appreciation rights plan, performance target plan).

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (c)(2)(iii)(1)
-URI http://asc.fasb.org/extlink&oid=96867065&loc=d3e5070-113901

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- Definition

Amount of cash paid related to share-based compensation liabilities.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (d)(2)
-URI http://asc.fasb.org/extlink&oid=96867065&loc=d3e5070-113901

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- Definition

Fair value of share-based awards for which the grantee gained the right by satisfying service and performance requirements, to receive or retain shares or units, other instruments, or cash.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (d)(2)
-URI http://asc.fasb.org/extlink&oid=96867065&loc=d3e5070-113901

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- Definition

The highest quantity of shares an employee can purchase under the plan per period.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 50
-Paragraph 2
-URI http://asc.fasb.org/extlink&oid=96867065&loc=d3e5070-113901

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- Definition

The difference between the maximum number of shares (or other type of equity) authorized for issuance under the plan (including the effects of amendments and adjustments), and the sum of: 1) the number of shares (or other type of equity) already issued upon exercise of options or other equity-based awards under the plan; and 2) shares (or other type of equity) reserved for issuance on granting of outstanding awards, net of cancellations and forfeitures, if applicable.

+ References

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- Definition

Amount of accumulated difference between fair value of underlying shares on dates of exercise and exercise price on options exercised (or share units converted) into shares.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (d)(2)
-URI http://asc.fasb.org/extlink&oid=96867065&loc=d3e5070-113901

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- Definition

Number of shares for which recognition of compensation cost was accelerated.

+ References

No definition available.

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- Definition

Fair value of options vested. Excludes equity instruments other than options, for example, but not limited to, share units, stock appreciation rights, restricted stock.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (c)
-URI http://asc.fasb.org/extlink&oid=96867065&loc=d3e5070-113901

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- Definition

Number of stock-equivalent units outstanding in deferred compensation accounts.

+ References

No definition available.

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Potential amount of shares of common stock that can be issued pursuant to performance incentive plan, shares.

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No definition available.

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- Definition

Number of replacement equity awards issued

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No definition available.

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- Definition

Maximum value of restricted stock, restricted stock units, performance shares, performance share units or other equity grants an individual may earn in a 12 month period.

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No definition available.

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Value of Replacement Stock Option Awards Issued

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SHARE-BASED COMPENSATION - Additional Information (Details) - USD ($) $ / shares in Units, $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015	Feb. 19, 2016
Deferred Compensation Arrangement with Individual, Share-based Payments [Line Items]
Employee Service Share-based Compensation, Tax Benefit from Exercise of Stock Options	$ 6	$ 12	$ 8
Share-based compensation expense	$ 40	$ 60	$ 31
Number of shares available for future grants under the Plan	21,092,207
Increase in common share if all share-based awards were exercised or vested	32,000,000
Unrecognized share-based compensation cost for non-vested equity-classified share-based compensation arrangements	$ 38
Unrecognized share-based compensation costs for non-vested equity-classified share-based compensation arrangements, weighted average period for recognition	2 years
Number of common shares to be issued for directors who elected common share payments subsequent to year-end	615,604
Number of stock-equivalent units outstanding in deferred compensation accounts	803,850	1,004,448	1,003,053
Stock options and stock appreciation rights
Deferred Compensation Arrangement with Individual, Share-based Payments [Line Items]
Number of shares of shares an individual may receive in one year	2,000,000
Restricted stock, restricted stock units, performance shares, performance share units, or other equity grants
Deferred Compensation Arrangement with Individual, Share-based Payments [Line Items]
Number of shares of shares an individual may receive in one year	1,000,000
Value of awards a participant may be granted in a 12 month period	$ 10
Stock options
Deferred Compensation Arrangement with Individual, Share-based Payments [Line Items]
Total intrinsic value of stock options exercised	68	$ 18	$ 13
Total grant-date fair value of stock options vested	$ 5	$ 14	$ 14
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Period	4 years
Restricted stock units
Deferred Compensation Arrangement with Individual, Share-based Payments [Line Items]
Weighted average grant-date fair value	$ 32.83	$ 30.25	$ 35.41
Total grant-date fair value vested	$ 18	$ 36	$ 14
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Period	4 years
Performance share units
Deferred Compensation Arrangement with Individual, Share-based Payments [Line Items]
Weighted average grant-date fair value	$ 37.93	$ 22.58	$ 34.75
Total grant-date fair value vested	$ 4	$ 8	$ 9
Stock appreciation rights
Deferred Compensation Arrangement with Individual, Share-based Payments [Line Items]
Total liabilities paid for stock appreciation rights	1	1	1
Discontinued operations
Deferred Compensation Arrangement with Individual, Share-based Payments [Line Items]
Employee Service Share-based Compensation, Tax Benefit from Exercise of Stock Options		2	2
Share-based compensation expense		6	6
Plum Creek
Deferred Compensation Arrangement with Individual, Share-based Payments [Line Items]
Acceleration of share-based compensation	$ 0	$ 21	$ 0
Plum Creek \| Stock options
Deferred Compensation Arrangement with Individual, Share-based Payments [Line Items]
Number of replacement equity awards issued				1,953,128
Value of replacement stock option awards issued				$ 5
Plum Creek \| Restricted stock units
Deferred Compensation Arrangement with Individual, Share-based Payments [Line Items]
Number of replacement equity awards issued				1,248,006
Replacement RSUs with accelerated vesting	705,394
Acceleration of share-based compensation	$ 15
Plum Creek \| Value management awards
Deferred Compensation Arrangement with Individual, Share-based Payments [Line Items]
Number of replacement equity awards issued				289,910
Acceleration of share-based compensation	$ 6