XML 97 R79.htm IDEA: XBRL DOCUMENT v3.8.0.1

Quarterly Financial Data (Unaudited) (Details Textual) - USD ($) $ / shares in Units, $ in Millions	3 Months Ended	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2017
Schedule Of Quarterly Financial Information [Line Items]
Effective Income Tax Rate Reconciliation, Change in Enacted Tax Rate, Amount	$ 7.8	$ 7.8
Increase In Basic Earnings Per Share From Change In Enacted Tax Rate	$ 0.48	$ 0.48
Increase In Diluted Earnings Per Share From Change In Enacted Tax Rate	$ 0.47	$ 0.47

X

- Definition

The per share increase in basic earnings from change in enacted tax rate.

+ References

No definition available.

+ Details

Name:	myrg_IncreaseInBasicEarningsPerShareFromChangeInEnactedTaxRate
Namespace Prefix:	myrg_
Data Type:	num:perShareItemType
Balance Type:	na
Period Type:	duration

X

- Definition

The per share increase in diluted earnings from change in enacted tax rate.

+ References

No definition available.

+ Details

Name:	myrg_IncreaseInDilutedEarningsPerShareFromChangeInEnactedTaxRate
Namespace Prefix:	myrg_
Data Type:	num:perShareItemType
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:	myrg_ScheduleOfQuarterlyFinancialInformationLineItems
Namespace Prefix:	myrg_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

X

- Definition

Amount of the difference between reported income tax expense (benefit) and expected income tax expense (benefit) computed by applying the domestic federal statutory income tax rates to pretax income (loss) from continuing operations, attributable to increase (decrease) in the income tax rates.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 740
-SubTopic 10
-Section 50
-Paragraph 12
-URI http://asc.fasb.org/extlink&oid=84230637&loc=d3e32687-109319

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 740
-SubTopic 10
-Section 50
-Paragraph 13
-URI http://asc.fasb.org/extlink&oid=84230637&loc=d3e32698-109319

Reference 3: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 740
-SubTopic 10
-Section 45
-Paragraph 15
-URI http://asc.fasb.org/extlink&oid=84176650&loc=d3e32059-109318

+ Details

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