XML 123 R100.htm IDEA: XBRL DOCUMENT v3.6.0.2

Supplemental Oil and Gas Disclosures (Unaudited) - Summary of Estimated Quantities of Proved Developed Oil and Natural Gas Reserves (Detail) bbl in Thousands, Mcf in Thousands		12 Months Ended
		Dec. 31, 2016 bbl Mcf	Dec. 31, 2015 bbl Mcf	Dec. 31, 2015 bbl Mcf	Dec. 31, 2014 bbl Mcf
Oil
Reserve Quantities [Line Items]
Beginning Balance	[1]	5,179	7,672
Proved developed reserves	[1]	446	5,179	5,179	5,269
Proved undeveloped reserves	[1]	0	0	0	2,403
Ending Balance	[1]	446	5,179		7,672
Natural Gas
Reserve Quantities [Line Items]
Beginning Balance | Mcf		9,220		14,400
Proved developed reserves | Mcf		5,035	9,220	9,220	12,599
Proved undeveloped reserves | Mcf		0	0	0	1,801
Ending Balance | Mcf		5,035		9,220	14,400
Consolidated Entities
Reserve Quantities [Line Items]
Revisions of previous estimates					608
Consolidated Entities | Oil
Reserve Quantities [Line Items]
Beginning Balance	[1]	5,179	7,672		5,824
Revisions of previous estimates	[1]	(11)	855		608
Extensions and discoveries	[1]	29	224		2,191
Acquisitions	[1]	0	0		85
Sales	[1]	(4,460)	(704)		(105)
Production	[1]	(291)	(1,158)		(931)
Ending Balance	[1]	446	5,179		7,672
Consolidated Entities | Natural Gas
Reserve Quantities [Line Items]
Beginning Balance | Mcf		7,957		12,649	13,630
Revisions of previous estimates		631	1,995	1,675	293
Extensions and discoveries | Mcf		0		173	774
Acquisitions | Mcf		0		0	31
Sales | Mcf		(3,756)		(1,223)	(218)
Production | Mcf		(996)		(1,967)	(1,861)
Ending Balance | Mcf		3,836		7,957	12,649
Equity Method Investee | Oil
Reserve Quantities [Line Items]
Beginning Balance	[1]	0	0		0
Revisions of previous estimates	[1]	0	0		0
Production	[1]	0	0		0
Ending Balance	[1]	0	0		0
Equity Method Investee | Natural Gas
Reserve Quantities [Line Items]
Beginning Balance | Mcf		1,263		1,751	2,332
Revisions of previous estimates | Mcf		79		(320)	(382)
Production | Mcf		(143)		(168)	(199)
Ending Balance | Mcf		1,199		1,263	1,751
[1] Includes natural gas liquids (NGLs).

X

- Definition

Proved Developed Reserves

+ References

No definition available.

+ Details

Name:	for_ProvedDevelopedReserves
Namespace Prefix:	for_
Data Type:	num:volumeItemType
Balance Type:	na
Period Type:	instant

X

- Definition

Proved Developed Reserves Acquired

+ References

No definition available.

+ Details

Name:	for_ProvedDevelopedReservesAcquired
Namespace Prefix:	for_
Data Type:	num:volumeItemType
Balance Type:	na
Period Type:	duration

X

- Definition

Proved Undeveloped Reserves

+ References

No definition available.

+ Details

Name:	for_ProvedUndevelopedReserves
Namespace Prefix:	for_
Data Type:	num:volumeItemType
Balance Type:	na
Period Type:	instant

X

- Definition

Additions to proved reserves that result from (1) extension of the proved acreage of previously discovered (old) reservoirs through additional drilling in periods after discovery and (2) discovery of new fields with proved reserves or of new reservoirs of proved reserves in old fields.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 932
-SubTopic 235
-Section 50
-Paragraph 5
-Subparagraph (d)
-URI http://asc.fasb.org/extlink&oid=68064819&loc=d3e61831-109447

+ Details

Name:	us-gaap_ProvedDevelopedAndUndevelopedReservesExtensionsDiscoveriesAndAdditions
Namespace Prefix:	us-gaap_
Data Type:	num:volumeItemType
Balance Type:	na
Period Type:	duration

X

- Definition

The net quantity of proved reserves as of the balance sheet date. Proved oil reserves are the estimated quantities of crude oil and natural gas liquids which geological and engineering data demonstrate with reasonable certainty to be recoverable.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 932
-SubTopic 235
-Section 50
-Paragraph 5
-URI http://asc.fasb.org/extlink&oid=68064819&loc=d3e61831-109447

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 932
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.4-10.(a)(2))
-URI http://asc.fasb.org/extlink&oid=50486907&loc=d3e511914-122862

+ Details

Name:	us-gaap_ProvedDevelopedAndUndevelopedReservesNet
Namespace Prefix:	us-gaap_
Data Type:	num:volumeItemType
Balance Type:	na
Period Type:	instant

X

- Definition

Production of proved reserves.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 932
-SubTopic 235
-Section 50
-Paragraph 5
-Subparagraph (e)
-URI http://asc.fasb.org/extlink&oid=68064819&loc=d3e61831-109447

+ Details

Name:	us-gaap_ProvedDevelopedAndUndevelopedReservesProduction
Namespace Prefix:	us-gaap_
Data Type:	num:volumeItemType
Balance Type:	na
Period Type:	duration

X

- Definition

Revisions represent changes in previous estimates of proved reserves, either upward or downward, resulting from new information (except for an increase in proved acreage) normally obtained from development drilling and production history or resulting from change in economic factors.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 932
-SubTopic 235
-Section 50
-Paragraph 5
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=68064819&loc=d3e61831-109447

+ Details

Name:	us-gaap_ProvedDevelopedAndUndevelopedReservesRevisionsOfPreviousEstimatesIncreaseDecrease
Namespace Prefix:	us-gaap_
Data Type:	num:volumeItemType
Balance Type:	na
Period Type:	duration

X

- Definition

Sales of minerals in place.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 932
-SubTopic 235
-Section 50
-Paragraph 5
-Subparagraph (f)
-URI http://asc.fasb.org/extlink&oid=68064819&loc=d3e61831-109447

+ Details

Name:	us-gaap_ProvedDevelopedAndUndevelopedReservesSalesOfMineralsInPlace
Namespace Prefix:	us-gaap_
Data Type:	num:volumeItemType
Balance Type:	na
Period Type:	duration

X

- Definition

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.

+ Details

Name:	us-gaap_ReserveQuantitiesLineItems
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

X

- Details

Name:	us-gaap_ReserveQuantitiesByTypeOfReserveAxis=us-gaap_OilReservesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	us-gaap_ReserveQuantitiesByTypeOfReserveAxis=us-gaap_NaturalGasReservesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	dei_LegalEntityAxis=us-gaap_ConsolidatedEntitiesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	dei_LegalEntityAxis=us-gaap_EquityMethodInvesteeMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: