XML 59 R43.htm IDEA: XBRL DOCUMENT v3.20.4

Note 6 - Leases (Details Textual)	12 Months Ended
	Dec. 31, 2020
Lessee, Operating Lease, Renewal Term (Year)	5 years
Minimum [Member]
Lessee, Remaining Lease Term (Year)	1 year
Maximum [Member]
Lessee, Remaining Lease Term (Year)	5 years

X

- Definition

Remaining term for lessee's leases.

+ References

No definition available.

+ Details

Name:	grc_LesseeRemainingLeaseTerm
Namespace Prefix:	grc_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

X

- Definition

Term of lessee's operating lease renewal, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents reported fact of one year, five months, and thirteen days.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 842
-SubTopic 20
-Section 50
-Paragraph 3
-Subparagraph (a)(3)
-URI http://asc.fasb.org/extlink&oid=121609121&loc=SL77918673-209980

+ Details

Name:	us-gaap_LesseeOperatingLeaseRenewalTerm
Namespace Prefix:	us-gaap_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	instant

X

- Details

Name:	srt_RangeAxis=srt_MinimumMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	srt_RangeAxis=srt_MaximumMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: