Name:	gnrc_Note17SpecialCashDividendsDetailsLineItems
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Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

The cumulative amount of the reporting entity's undistributed earnings or deficit as of the dividend declaration date.

+ References

No definition available.

+ Details

Name:	gnrc_RetainedEarningsDividendDeclarationDate
Namespace Prefix:	gnrc_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Carrying value as of the balance sheet date of special cash dividends declared but unpaid on equity securities issued by the entity and outstanding.

+ References

No definition available.

+ Details

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Namespace Prefix:	gnrc_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Aggregate dividends declared during the period for each share of common stock outstanding.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 04

-Article 3

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 505

-SubTopic 10

-Section S99

-Paragraph 1

-Subparagraph (SX 210.3-04)

-URI http://asc.fasb.org/extlink&oid=27012166&loc=d3e187085-122770

+ Details

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Namespace Prefix:	us-gaap_
Data Type:	num:perShareItemType
Balance Type:	na
Period Type:	duration

- Definition

Amount of paid and unpaid common stock dividends declared with the form of settlement in cash.

+ References

+ Details

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

- 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=31042434&loc=d3e3602-108585

+ Details

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

- Details

Name:	us-gaap_DividendsAxis=gnrc_SpecialCashDividend2012Member
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- Details

Name:	us-gaap_DividendsAxis=gnrc_SpecialCashDividend2013Member
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Note 17 - Special Cash Dividends (Details) (USD $)	1 Months Ended		12 Months Ended			1 Months Ended
Note 17 - Special Cash Dividends (Details) (USD $)	May 31, 2013	May 30, 2012	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012	Jun. 29, 2012	Jun. 21, 2013
Note 17 - Special Cash Dividends (Details) [Line Items]
Common Stock, Dividends, Per Share, Declared (in Dollars per share)	$ 5.00	$ 6.00	$ 0	$ 5.00	$ 6.00
Share-based Compensation			$ 12,612,000us-gaap_ShareBasedCompensation	$ 12,368,000us-gaap_ShareBasedCompensation	$ 10,780,000us-gaap_ShareBasedCompensation
Special Cash Dividend 2012 [Member]
Note 17 - Special Cash Dividends (Details) [Line Items]
Common Stock, Dividends, Per Share, Declared (in Dollars per share)						$ 6.00
Dividends, Common Stock, Cash						404,332,000
Special Cash Dividends Declared but Unpaid			731,000
Share-based Compensation					0
Special Cash Dividend 2013 [Member]
Note 17 - Special Cash Dividends (Details) [Line Items]
Common Stock, Dividends, Per Share, Declared (in Dollars per share)							$ 5.00
Dividends, Common Stock, Cash							340,772,000
Special Cash Dividends Declared but Unpaid			810,000
Retained Earnings Dividend Declaration Date							4,934,000
Share-based Compensation				$ 0