This item represents the gross unrealized gains for securities.

No definition available.

Name:	earn_GrossUnrealizedGainOnSecurities
Namespace Prefix:	earn_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

This item represents the gross unrealized losses for securities.

+ References

No definition available.

+ Details

Name:	earn_GrossUnrealizedLossesOnSecurities
Namespace Prefix:	earn_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

[Line Items] for Mortgage-Backed Securities [Table]

+ References

No definition available.

+ Details

Name:	earn_MortgageBackedSecuritiesLineItems
Namespace Prefix:	earn_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

Weighted Average Coupon Rate, Percent

+ References

No definition available.

+ Details

Name:	earn_WeightedAverageCouponRatePercent
Namespace Prefix:	earn_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

Weighted Average Life

+ References

No definition available.

+ Details

Name:	earn_WeightedAverageLife
Namespace Prefix:	earn_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

- Definition

Weighted Average Yield, Percent

+ References

No definition available.

+ Details

Name:	earn_WeightedAverageYieldPercent
Namespace Prefix:	earn_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

The amount of debt discount (net of debt premium) that was originally recognized at the issuance of the instrument that has yet to be amortized.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 835

-SubTopic 30

-Section 45

-Paragraph 4

-URI http://asc.fasb.org/extlink&oid=6451184&loc=d3e28567-108399

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 835

-SubTopic 30

-Section 45

-Paragraph 1A

-URI http://asc.fasb.org/extlink&oid=6451184&loc=d3e28541-108399

Reference 3: 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=34725769&loc=d3e28878-108400

Reference 4: 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 5: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 835

-SubTopic 30

-Section 45

-Paragraph 3

-URI http://asc.fasb.org/extlink&oid=6451184&loc=d3e28555-108399

+ Details

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

- Definition

The fair value as of the balance sheet date of firm holdings in mortgages, mortgage backed securities (investment instruments that represent ownership of an undivided interest in a group of mortgages, where principal and interest from the individual mortgages are used to pay investors' principal and interest on the mortgage backed security) and asset-backed securities that are primarily paid from the cash flows of a discrete pool of receivables or other financial assets (such as credit-card receivables), either fixed or revolving, that by their terms convert into cash within a finite time period. Includes both pledged (to counterparties as collateral for financing transactions) and unpledged holdings.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 940

-SubTopic 320

-Section 45

-Paragraph 2

-URI http://asc.fasb.org/extlink&oid=35711157&loc=d3e42546-110969

+ Details

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

- Definition

Cost of the investment.

+ References

No definition available.

+ Details

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

- Definition

For investments which are quantified by principal amount, the principle balance held at close of period.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 946

-SubTopic 320

-Section S99

-Paragraph 6

-Subparagraph (SX 210.12-14.Column B)

-URI http://asc.fasb.org/extlink&oid=50485924&loc=d3e611322-123010

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 946

-SubTopic 320

-Section S99

-Paragraph 1

-Subparagraph (SX 210.12-12.Column B)

-URI http://asc.fasb.org/extlink&oid=50485924&loc=d3e611133-123010

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 946

-SubTopic 320

-Section S99

-Paragraph 4

-Subparagraph (SX 210.12-12C.Column B)

-URI http://asc.fasb.org/extlink&oid=50485924&loc=d3e611225-123010

+ Details

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

- Details

Name:	us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis=us-gaap_ResidentialMortgageBackedSecuritiesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis=us-gaap_MortgageBackedSecuritiesIssuedByPrivateEnterprisesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_SummaryOfInvestmentsOtherThanInvestmentsInRelatedPartiesByTypeAxis=earn_A15yearfixedratemortgagesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis=us-gaap_MortgageBackedSecuritiesIssuedByUSGovernmentSponsoredEnterprisesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_SummaryOfInvestmentsOtherThanInvestmentsInRelatedPartiesByTypeAxis=earn_A20yearfixedratemortgagesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_SummaryOfInvestmentsOtherThanInvestmentsInRelatedPartiesByTypeAxis=earn_A30yearfixedratemortgagesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_SummaryOfInvestmentsOtherThanInvestmentsInRelatedPartiesByTypeAxis=us-gaap_AdjustableRateResidentialMortgageMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_SummaryOfInvestmentsOtherThanInvestmentsInRelatedPartiesByTypeAxis=earn_ReversemortgagesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_SummaryOfInvestmentsOtherThanInvestmentsInRelatedPartiesByTypeAxis=us-gaap_InterestOnlyStripMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_SummaryOfInvestmentsOtherThanInvestmentsInRelatedPartiesByTypeAxis=us-gaap_AgencySecuritiesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: