XML 55 R27.htm IDEA: XBRL DOCUMENT
v2.4.0.8

Mortgage Backed Securities Mortgage backed securities designated as AFS (Details) (USD $) In Thousands, unless otherwise specified | 3 Months Ended | 12 Months Ended | 3 Months Ended | 12 Months Ended | 3 Months Ended | 12 Months Ended | 3 Months Ended | 12 Months Ended | 3 Months Ended | 12 Months Ended | 3 Months Ended | 12 Months Ended | 3 Months Ended | 12 Months Ended | 3 Months Ended | 12 Months Ended | 3 Months Ended | 12 Months Ended | 3 Months Ended |  | 3 Months Ended |
--- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | ---
Mar. 31, 2014 | Dec. 31, 2013 | Mar. 31, 2014 Agency MBS [Member] | Dec. 31, 2013 Agency MBS [Member] | Mar. 31, 2014 Agency MBS [Member] Residential Mortgage Backed Securities [Member] | Dec. 31, 2013 Agency MBS [Member] Residential Mortgage Backed Securities [Member] | Mar. 31, 2014 Agency MBS [Member] Commercial Mortgage Backed Securities [Member] | Dec. 31, 2013 Agency MBS [Member] Commercial Mortgage Backed Securities [Member] | Mar. 31, 2014 Agency MBS [Member] CMBS IO [Member] | Dec. 31, 2013 Agency MBS [Member] CMBS IO [Member] | Mar. 31, 2014 Non-Agency MBS [Member] | Dec. 31, 2013 Non-Agency MBS [Member] | Mar. 31, 2014 Non-Agency MBS [Member] Residential Mortgage Backed Securities [Member] | Dec. 31, 2013 Non-Agency MBS [Member] Residential Mortgage Backed Securities [Member] | Mar. 31, 2014 Non-Agency MBS [Member] Commercial Mortgage Backed Securities [Member] | Dec. 31, 2013 Non-Agency MBS [Member] Commercial Mortgage Backed Securities [Member] | Mar. 31, 2014 Non-Agency MBS [Member] CMBS IO [Member] | Dec. 31, 2013 Non-Agency MBS [Member] CMBS IO [Member] | Mar. 31, 2014 Agency MBS [Member] | Mar. 31, 2013 Agency MBS [Member] | Dec. 31, 2013 Agency MBS [Member] | Mar. 31, 2014 Non-Agency MBS [Member] | Mar. 31, 2013 Non-Agency MBS [Member] | Dec. 31, 2013 Non-Agency MBS [Member]
Schedule of Available-for-sale Securities [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Available-for-sale MBS, Par Balance | $ 3,115,727 | $ 3,254,946 | $ 2,725,064 | $ 2,865,398 | $ 2,438,133 | $ 2,591,568 | $ 286,931 | $ 273,830 | $ 0 | $ 0 | $ 390,663 | $ 389,548 | $ 15,454 | $ 13,845 | $ 375,209 | $ 375,703 | $ 0 | $ 0 |  |  |  |  |  |
Investments, Unamortized Premium (Discount) | 812,735 | 758,950 | 621,260 | 627,047 | 139,899 | 154,220 | 19,838 | 19,061 | 461,523 | 453,766 | 191,475 | 131,903 | (7) | (338) | (17,819) | (18,277) | 209,301 | 150,518 |  |  |  |  |  |
Notional balance for interest only securities |  |  |  |  |  |  |  |  | 10,582,484 | 10,160,502 |  |  |  |  |  |  | 5,053,884 | 4,274,957 |  |  |  |  |  |
Available-for-sale MBS, Amortized Cost | 3,928,462 | 4,013,896 | 3,346,324 | 3,492,445 | 2,578,032 | 2,745,788 | 306,769 | 292,891 | 461,523 | 453,766 | 582,138 | 521,451 | 15,447 | 13,507 | 357,390 | 357,426 | 209,301 | 150,518 |  |  |  |  |  |
Available-for-sale MBS, Gross Unrealized Gain | 52,704 | 45,114 | 29,673 | 26,792 | 6,708 | 6,104 | 11,384 | 10,793 | 11,581 | 9,895 | 23,031 | 18,322 | 209 | 338 | 19,448 | 15,366 | 3,374 | 2,618 |  |  |  |  |  |
Available-for-sale MBS, Gross Unrealized Loss | 49,882 | 69,566 | 47,806 | 63,976 | 45,438 | 59,742 | 509 | 900 | 1,859 | 3,334 | 2,076 | 5,590 | (86) | 80 | 842 | 3,511 | (1,148) | 1,999 |  |  |  |  |  |
Available-for-sale MBS, Fair Value | 3,931,284 | 3,989,444 | 3,328,191 | 3,455,261 | 2,539,302 | 2,692,150 | 317,644 | 302,784 | 471,245 | 460,327 | 603,093 | 534,183 | 15,570 | 13,765 | 375,996 | 369,281 | 211,527 | 151,137 |  |  |  |  |  |
Available-for-sale MBS, Weighted Average Coupon |  |  |  |  | 3.20% | 3.22% | 5.23% | 5.07% | 0.94% | 0.83% |  |  | 4.42% | 4.61% | 5.05% | 5.10% | 0.80% | 0.66% |  |  |  |  |  |
Available-for-sale MBS, Continuous Unrealized Loss Position, Less than Twelve Months, Fair Value |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 1,563,078 |  | 1,912,937 | 126,578 |  | 162,558
Available-for-sale MBS, Continuous Unrealized Loss Position, Less than 12 Months, Gross Unrealized Losses |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | (29,207) | (43,543) |  | (1,990) | (5,435) |
Available-for-sale MBS, Number of Securities in Continuous Unrealized Loss Position for Less than One Year |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 120 |  | 150 | 23 |  | 39
Available-for-sale MBS, Continuous Unrealized Loss Position, Twelve Months or Longer, Fair Value |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 767,744 |  | 670,402 | 1,676 |  | 6,310
Available-for-sale MBS, Continuous Unrealized Loss Position, 12 Months or Longer, Gross Unrealized Losses |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | $ (18,600) | $ (20,433) |  | $ (86) | $ (155) |
Available-for-sale MBS, Number of Securities in Continuous Unrealized Loss Position for Greater than or Equal to One Year |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 80 |  | 67 | 5 |  | 6

X
- Definition The remaining amount of investment premium (discount), net, originally recognized at the purchase date of the instruments that has yet to be amortized (accreted) into earnings. + References No definition available. + Details
Name: | dx_InvestmentsUnamortizedPremiumDiscount
Namespace Prefix: | dx_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition This item represents the current weighted-average gross interest rate earned on this type of MBS in the investment portfolio as of the period indicated. The gross interest rate of each MBS within the portfolio is weighted based on its current outstanding notional or par balance. The current outstanding notional or par balance for each MBS consists of the total of all principal balances remaining on the mortgage loans underlying each MBS. + References No definition available. + Details
Name: | dx_InvestmentsWeightedAverageCouponRate
Namespace Prefix: | dx_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | instant

X
- Definition Notional balance for interest only securities owned by the Company. Interest only securities represent the right to receive excess interest payments, and not principal cash flows, based on the underlying unpaid principal balance (ie, notional) of the underlying pool of mortgage loans. + References No definition available. + Details
Name: | dx_Notionalbalanceforinterestonlysecurities
Namespace Prefix: | dx_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition This item represents the cost of debt securities, which are categorized neither as held-to-maturity nor trading, net of adjustments including accretion, amortization, collection of cash, previous other-than-temporary impairments recognized in earnings (less any cumulative-effect adjustments recognized, as defined), and fair value hedge accounting adjustments, if any. + References No definition available. + Details
Name: | us-gaap_AvailableForSaleDebtSecuritiesAmortizedCostBasis
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Amount of unrealized gain before deducting unrealized loss on investments in debt securities classified as available-for-sale securities. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 320 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=27724398&loc=d3e27161-111563 + Details
Name: | us-gaap_AvailableForSaleDebtSecuritiesGrossUnrealizedGain
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition Amount of unrealized loss before deducting unrealized gain on investments in available-for-sale debt securities. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 320 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (c) -URI http://asc.fasb.org/extlink&oid=27724398&loc=d3e27161-111563 + Details
Name: | us-gaap_AvailableForSaleDebtSecuritiesGrossUnrealizedLoss
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Amount of unrealized loss on securities classified as available-for-sale that have been in a loss position for twelve months or longer. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 320 -SubTopic 10 -Section 50 -Paragraph 6 -Subparagraph (a)(2) -URI http://asc.fasb.org/extlink&oid=27724398&loc=d3e27290-111563 + Details
Name: | us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPosition12MonthsOrLongerAggregateLosses
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Amount of unrealized loss on investments in available-for-sale securities that have been in a loss position for less than twelve months. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 320 -SubTopic 10 -Section 50 -Paragraph 7 -URI http://asc.fasb.org/extlink&oid=27724398&loc=d3e27337-111563 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 320 -SubTopic 10 -Section 50 -Paragraph 6 -Subparagraph (a)(2) -URI http://asc.fasb.org/extlink&oid=27724398&loc=d3e27290-111563 + Details
Name: | us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPositionLessThan12MonthsAggregateLosses
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition This item represents the aggregate fair value of investments in debt and equity securities categorized neither as held-to-maturity nor trading securities that have been in a continuous unrealized loss position for less than twelve months. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 320 -SubTopic 10 -Section 50 -Paragraph 7 -URI http://asc.fasb.org/extlink&oid=27724398&loc=d3e27337-111563 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 320 -SubTopic 10 -Section 50 -Paragraph 6 -Subparagraph (a)(1) -URI http://asc.fasb.org/extlink&oid=27724398&loc=d3e27290-111563 + Details
Name: | us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPositionLessThanTwelveMonthsFairValue
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition This item represents the aggregate fair value of investments in debt and equity securities categorized neither as held-to-maturity nor trading securities that have been in a continuous unrealized loss position for twelve months or longer. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 320 -SubTopic 10 -Section 50 -Paragraph 7 -URI http://asc.fasb.org/extlink&oid=27724398&loc=d3e27337-111563 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 320 -SubTopic 10 -Section 50 -Paragraph 6 -Subparagraph (a)(1) -URI http://asc.fasb.org/extlink&oid=27724398&loc=d3e27290-111563 + Details
Name: | us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPositionTwelveMonthsOrLongerFairValue
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Amount of debt securities categorized neither as held-to-maturity nor trading. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 320 -SubTopic 10 -Section 25 -Paragraph 1 -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=28360136&loc=d3e22054-111558 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 320 -SubTopic 10 -Section 45 -Paragraph 1 -URI http://asc.fasb.org/extlink&oid=6871852&loc=d3e26610-111562 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 320 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (aa) -URI http://asc.fasb.org/extlink&oid=27724398&loc=d3e27161-111563 Reference 4: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 942 -SubTopic 320 -Section 50 -Paragraph 2 -Subparagraph (b)-(g) -URI http://asc.fasb.org/extlink&oid=6957658&loc=d3e62557-112803 + Details
Name: | us-gaap_AvailableForSaleSecuritiesDebtSecurities
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Number of investment positions in available-for-sale investments that have been in a continuous unrealized loss position for greater than or equal to a year for which an other-than-temporary impairment (OTTI) has not been recognized in the income statement. + References No definition available. + Details
Name: | us-gaap_AvailableforsaleSecuritiesInUnrealizedLossPositionsQualitativeDisclosureNumberOfPositionsGreaterThanOrEqualToOneYear
Namespace Prefix: | us-gaap_
Data Type: | xbrli:integerItemType
Balance Type: | na
Period Type: | instant

X
- Definition Number of investment positions in available-for-sale investments in a continuous unrealized loss position for less than one year or normal operating cycle, if longer, for which an other-than-temporary impairment (OTTI) has not been recognized in the income statement. + References No definition available. + Details
Name: | us-gaap_AvailableForSaleSecuritiesInUnrealizedLossPositionsQualitativeDisclosureNumberOfPositionsLessThanOneYear
Namespace Prefix: | us-gaap_
Data Type: | xbrli:integerItemType
Balance Type: | na
Period Type: | instant

X
- 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 4 -Subparagraph (SX 210.12-12C.Column B) -URI http://asc.fasb.org/extlink&oid=6955306&loc=d3e611225-123010 Reference 2: 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=6955306&loc=d3e611322-123010 Reference 3: 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=6955306&loc=d3e611133-123010 Reference 4: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 12C -Paragraph Column B -Article 12 Reference 5: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 12 -Paragraph Column B -Article 12 Reference 6: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 14 -Paragraph Column B -Article 12 + Details
Name: | us-gaap_InvestmentOwnedBalancePrincipalAmount
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Details
Name: | us-gaap_ScheduleOfAvailableForSaleSecuritiesLineItems
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration