Investment in Related Party

No definition available.

Name:	pegi_InvestmentinRelatedParty
Namespace Prefix:	pegi_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Ownership Interest in the Company by Pattern Development

+ References

No definition available.

+ Details

Name:	pegi_OwnershipInterestintheCompanybyPatternDevelopment
Namespace Prefix:	pegi_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

Ownership Percentage

+ References

No definition available.

+ Details

Name:	pegi_OwnershipPercentage
Namespace Prefix:	pegi_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

Schedule Of Description Of Business [Line Items]

+ References

No definition available.

+ Details

Name:	pegi_ScheduleOfDescriptionOfBusinessLineItems
Namespace Prefix:	pegi_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

This element represents the aggregate cost of investments accounted for under the equity method of accounting.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02.12)
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

+ Details

Name:	us-gaap_EquityMethodInvestmentAggregateCost
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

The percentage of ownership of common stock or equity participation in the investee accounted for under the equity method of accounting.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 323
-SubTopic 10
-Section 50
-Paragraph 3
-Subparagraph (a)(1)
-URI http://asc.fasb.org/extlink&oid=66011266&loc=d3e33918-111571

+ Details

Name:	us-gaap_EquityMethodInvestmentOwnershipPercentage
Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

This item represents the carrying amount on the entity's balance sheet of its investment in common stock of an equity method investee. This is not an indicator of the fair value of the investment, rather it is the initial cost adjusted for the entity's share of earnings and losses of the investee, adjusted for any distributions (dividends) and other than temporary impairment (OTTI) losses recognized.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 323
-SubTopic 10
-Section 45
-Paragraph 1
-URI http://asc.fasb.org/extlink&oid=66022249&loc=d3e33749-111570

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02.12)
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

+ Details

Name:	us-gaap_EquityMethodInvestments
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Purchases during the period (excluding transactions that are eliminated in consolidated or combined financial statements) with related party.

+ References

No definition available.

+ Details

Name:	us-gaap_RelatedPartyTransactionPurchasesFromRelatedParty
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

Organization - Additional Information (Detail) - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2018	Aug. 09, 2018	Dec. 31, 2017	Jun. 30, 2017
Schedule Of Description Of Business [Line Items]
Equity Method Investments	$ 343,512		$ 311,223
Purchases from related party	27,000
Pattern Development 2.0 [Member]
Schedule Of Description Of Business [Line Items]
Equity method investment, aggregate cost	$ 124,400
Percentage of ownership	24.00%
Investment in related party	$ 57,100
Pattern Development [Member]
Schedule Of Description Of Business [Line Items]
Ownership Interest in the Company by Pattern Development				5.10%
Hatchet Ridge [Member]
Schedule Of Description Of Business [Line Items]
Ownership percentage	100.00%
St Josephs [Member]
Schedule Of Description Of Business [Line Items]
Ownership percentage	100.00%
Spring Valley [Member]
Schedule Of Description Of Business [Line Items]
Ownership percentage	100.00%
Pattern Santa Isabel LLC [Member]
Schedule Of Description Of Business [Line Items]
Ownership percentage	100.00%
Ocotillo [Member]
Schedule Of Description Of Business [Line Items]
Ownership percentage	100.00%
Pattern Gulf Wind LLC [Member]
Schedule Of Description Of Business [Line Items]
Ownership percentage	100.00%
Lost Creek Wind, LLC [Member]
Schedule Of Description Of Business [Line Items]
Ownership percentage	100.00%
Green Power Tsugaru G.K. [Member]
Schedule Of Description Of Business [Line Items]
Ownership percentage	100.00%
Green Power Generation G.K. [Member]
Schedule Of Description Of Business [Line Items]
Ownership percentage	100.00%
GK Green Power Otsuki [Member]
Schedule Of Description Of Business [Line Items]
Ownership percentage	100.00%
GK Green Power Kanagi [Member]
Schedule Of Description Of Business [Line Items]
Ownership percentage	100.00%
GK Green Power Futtsu [Member]
Schedule Of Description Of Business [Line Items]
Ownership percentage	100.00%
Subsequent Event [Member] \| Pattern Development 2.0 [Member]
Schedule Of Description Of Business [Line Items]
Investment in related party		$ 29,000