Percentage of face value that the debt instrument was issued at.

No definition available.

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- Definition

Represents the initial premium percentage, which steps down over time, to be paid to the lender in the event the debt is repaid prior to maturity.

+ References

No definition available.

+ Details

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- Definition

Represents the percentage of principal amount of the debt required to be paid to the lender in the event the debt is repaid prior to maturity.

+ References

No definition available.

+ Details

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- Definition

No authoritative reference available.

+ References

No definition available.

+ Details

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Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

No authoritative reference available.

+ References

No definition available.

+ Details

Name:	meg_LoanDiscountPercent
Namespace Prefix:	meg_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

No authoritative reference available.

+ References

No definition available.

+ Details

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Balance Type:	na
Period Type:	duration

- Definition

The amount of cash paid for payment-in-kind (PIK) interest previously accrued during the period.

+ References

No definition available.

+ Details

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Namespace Prefix:	meg_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

The specified number of securities that each class of warrants or rights outstanding give the holder the right but not the obligation to purchase from the issuer at a specific price, on or before a certain date.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 235

-SubTopic 10

-Section S99

-Paragraph 1

-Subparagraph (SX 210.4-08.(i)(2))

-URI http://asc.fasb.org/extlink&oid=6881521&loc=d3e23780-122690

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

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 08

-Paragraph i

-Subparagraph 2

-Article 4

+ Details

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Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	instant

- Definition

The percentage points added to the reference rate to compute the variable rate on the debt instrument.

+ References

No definition available.

+ Details

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Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
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- Definition

Including current and noncurrent portions, aggregate carrying amount of long-term borrowings as of the balance sheet date before deducting unamortized discount or premiums (if any). May include notes payable, bonds payable, commercial loans, mortgage loans, convertible debt, subordinated debt and other types of debt, which had initial maturities beyond one year or beyond the normal operating cycle, if longer.

+ References

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

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 03

-Paragraph 16

-Article 9

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

-Publisher FASB

-Name FASB Staff Position (FSP)

-Number APB14-1

-Paragraph 31

-Subparagraph b

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 3: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 02

-Paragraph 20

-Article 5

Reference 4: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 210

-SubTopic 10

-Section S99

-Paragraph 1

-Subparagraph (SX 210.5-02.22)

-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

Reference 5: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 02

-Paragraph 22

-Article 5

+ Details

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Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

The stated principal amount of the debt instrument at time of issuance, which may vary from the carrying amount because of unamortized premium or discount.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 835

-SubTopic 30

-Section 45

-Paragraph 2

-URI http://asc.fasb.org/extlink&oid=6451184&loc=d3e28551-108399

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 835

-SubTopic 30

-Section 55

-Paragraph 8

-URI http://asc.fasb.org/extlink&oid=6584090&loc=d3e28878-108400

Reference 3: http://www.xbrl.org/2003/role/presentationRef

-Publisher AICPA

-Name Accounting Principles Board Opinion (APB)

-Number 21

-Paragraph 16, 20

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

+ Details

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Balance Type:	credit
Period Type:	instant

- Definition

Interest rate stated in the contractual debt agreement.

+ References

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

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 02

-Paragraph 22

-Article 5

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 210.5-02.22(a)(1))

-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

+ Details

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- Definition

When presenting a range of interest rates, the lowest stated (contractual) rate for funds borrowed under the debt agreement as of the balance sheet date.

+ References

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

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 02

-Paragraph 22

-Article 5

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 210.5-02.22(a)(2))

-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

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Period Type:	duration

- Definition

Amount borrowed under the credit facility as of the balance sheet date.

+ References

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

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 02

-Paragraph 19, 22

-Article 5

+ Details

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Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

The fee, expressed as a percentage of the line of credit facility, for the line of credit facility regardless of whether the facility has been used.

+ References

No definition available.

+ Details

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- Definition

The effective interest rate at the end of the reporting period.

+ 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 210.5-02.19(b),22(b))

-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

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

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 02

-Paragraph 19, 22

-Article 5

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- Definition

Maximum borrowing capacity under the credit facility without consideration of any current restrictions on the amount that could be borrowed or the amounts currently outstanding under the facility.

+ References

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

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 129

-Paragraph 2, 4

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

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 210.5-02.19(b),22(b))

-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

Reference 3: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 02

-Paragraph 19, 22

-Article 5

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Note 5. Long-Term Debt and Other Financial Instruments (Detail) (USD $) Share data in Millions, unless otherwise specified	1 Months Ended										3 Months Ended				3 Months Ended	5 Months Ended
	Mar. 31, 2012	May 31, 2012	May 31, 2012 Warrant Agreement with Berkshire Hathaway [Member]	Mar. 31, 2013 BH Finance LLC [Member] Step Down Percentage if Total Leverage Reaches Threshold [Member] Term Loan [Member]	Mar. 31, 2013 BH Finance LLC [Member] Term Loan [Member]	Dec. 31, 2012 BH Finance LLC [Member] Term Loan [Member]	May 31, 2012 BH Finance LLC [Member] Term Loan [Member]	Mar. 31, 2013 BH Finance LLC [Member] Revolving Credit Facility [Member]	Dec. 31, 2012 BH Finance LLC [Member] Revolving Credit Facility [Member]	May 31, 2012 BH Finance LLC [Member] Revolving Credit Facility [Member]	Mar. 31, 2013 BH Finance LLC [Member]	Mar. 31, 2013 Term Loan [Member]	Dec. 31, 2012 Term Loan [Member]	Mar. 31, 2013 Senior Notes [Member]	Mar. 25, 2012 Previous Bank Credit Facility [Member]	May 31, 2012 Previous Bank Credit Facility [Member]
Debt Instrument, Face Amount (in Dollars)					$ 302,000,000	$ 302,000,000						$ 301,537,000	$ 301,537,000	$ 300,000,000
Line of Credit Facility, Amount Outstanding (in Dollars)								0	0
Line of Credit Facility, Maximum Borrowing Capacity (in Dollars)								45,000,000	45,000,000	45,000,000
Debt Instrument, Interest Rate, Stated Percentage				9.00%	10.50%									11.75%
Debt Instrument Issuance Price Percentage Of Face Value														97.69%
Long-term Debt, Gross (in Dollars)							400,000,000
Loan Discount, Percent							11.50%
Debt Instrument Repayment Prior To Maturity Price As Percentage Of Principal Amount		100.00%
Debt Instrument Repayment Prior To Maturity Initial Premium Percentage		14.50%
Line of Credit Facility, Interest Rate at Period End											10.00%
Line of Credit Facility, Commitment Fee Percentage											2.00%					2.50%
Class of Warrant or Right, Number of Securities Called by Warrants or Rights (in Shares)			4.6
Debt Modification and Extinguishment Costs Relating to Amendment of Previous Bank Credit Agreement (in Dollars)	10,400,000
Debt Instrument, Interest Rate, Stated Percentage Rate Range, Minimum																1.50%
Debt Instrument, Basis Spread on Variable Rate																7.00%
Payment-in-kind (PIK) Interest, Percentage																1.50%
PIK Interest Paid (in Dollars)															$ 100,000