Name:	dx_Borrowingsoutstandingwithcounterparty
Namespace Prefix:	dx_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

[Line Items] for Counterparty Information [Table]

No definition available.

Name:	dx_CounterpartyInformationLineItems
Namespace Prefix:	dx_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

Number of counterparties with whom the Company has borrowing agreements.

No definition available.

Name:	dx_NumberOfCounterpartiesBorrowingAvailability
Namespace Prefix:	dx_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	instant

Number of lending counterparties with whom the Company has amounts outstanding as of reporting period.

No definition available.

Name:	dx_NumberOfCounterpartiesBorrowingsOutstanding
Namespace Prefix:	dx_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	instant

Weighted average interest rate on amounts outstanding with a particular counterparty for whom the amount of equity at risk exceeds 10% of the Company's shareholders' equity.

No definition available.

Name:	dx_WAVGinterestrateforamountoutstandingwithnamedcounterparty
Namespace Prefix:	dx_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

The amount at risk under repurchase agreements is defined as the excess of carrying amount (or market value, if higher than the carrying amount or if there is no carrying amount) of the securities or other assets sold under agreement to repurchase, including accrued interest plus any cash or other assets on deposit to secure the repurchase obligation, over the amount of the repurchase liability (adjusted for accrued interest).

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.(m)(1)(i)(B)(iii))
-URI http://asc.fasb.org/extlink&oid=26873400&loc=d3e23780-122690