XML 83 R54.htm IDEA: XBRL DOCUMENT
v3.19.3

SECURITIES - Unrealized Loss Position (Details) $ in Thousands | Sep. 30, 2019 USD ($) security | Dec. 31, 2018 USD ($) security
--- | --- | ---
Unrealized Loss Position For: |  |
Estimated Fair Value | $ 17,513,412 | $ 65,552,879
Gross Unrealized Losses | $ (159,777) | $ (2,285,609)
Number of Securities (security) | security | 551 | 2,189
Available For Sale Securities, Continuous Unrealized Loss Positions, Less Than 12 Months |  |
Unrealized Loss Position For: |  |
Estimated Fair Value | $ 3,524,012 | $ 22,418,036
Gross Unrealized Losses | $ (17,042) | $ (432,352)
Number of Securities (security) | security | 45 | 713
Available For Sale Securities, Continuous Unrealized Loss Positions, Greater Than 12 Months |  |
Unrealized Loss Position For: |  |
Estimated Fair Value | $ 13,989,400 | $ 43,134,843
Gross Unrealized Losses | $ (142,735) | $ (1,853,257)
Number of Securities (security) | security | 506 | 1,476

X
- Definition Mortgage-Backed Securities in a continuous unrealized loss position [Line Items] + References No definition available. + Details
Name: | nly_MortgagebackedSecuritiesInContinuousUnrealizedLossPositionLineItems
Namespace Prefix: | nly_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Amount of accumulated unrealized loss on investments in debt and equity securities classified as available-for-sale in a continuous loss position. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 320 -SubTopic 10 -Section 50 -Paragraph 7 -URI http://asc.fasb.org/extlink&oid=82897076&loc=d3e27337-111563 + Details
Name: | us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPositionAccumulatedLoss
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 in an unrealized loss position which are categorized neither as held-to-maturity nor trading securities. + References No definition available. + Details
Name: | us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPositionFairValue
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 in a continuous unrealized loss position for which an other-than-temporary impairment (OTTI) has not been recognized in the income statement. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 320 -SubTopic 10 -Section 50 -Paragraph 6 -Subparagraph (b)(3) -URI http://asc.fasb.org/extlink&oid=82897076&loc=d3e27290-111563 + Details
Name: | us-gaap_AvailableforsaleSecuritiesInUnrealizedLossPositionsQualitativeDisclosureNumberOfPositions1
Namespace Prefix: | us-gaap_
Data Type: | xbrli:integerItemType
Balance Type: | na
Period Type: | instant

X
- Details
Name: | us-gaap_InformationByCategoryOfDebtSecurityAxis=nly_AvailableForSaleSecuritiesContinuousUnrealizedLossPositionsLessThanTwelveMonthsMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_InformationByCategoryOfDebtSecurityAxis=nly_AvailableForSaleSecuritiesContinuousUnrealizedLossPositionsGreaterThanTwelveMonthsMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |