XML 133 R68.htm IDEA: XBRL DOCUMENT
v3.19.3.a.u2

LOANS - Internal Loan and Preferred Equity Ratings (Details) | 12 Months Ended
--- | ---
Dec. 31, 2019 USD ($) loan | Dec. 31, 2018 USD ($) loan | Dec. 31, 2017 USD ($)
Real Estate [Line Items] |  |  |
Outstanding principal | $ 113,123,301,000 | $ 96,602,237,000 |
Balance of the loan loss provision | 20,100,000 | 3,500,000 |
Loan loss provision | 16,569,000 | 3,496,000 | $ 0
Commercial Mortgage |  |  |
Real Estate [Line Items] |  |  |
Outstanding principal | $ 1,627,109,000 | $ 1,307,911,000 |
Percentage of CRE debt and preferred equity portfolio | 100.00% | 100.00% |
Performing | $ 584,076,000 | $ 793,842,000 |
Performing - closely monitored | 649,216,000 | 254,676,000 |
Performing - special mention | 240,014,000 | 151,400,000 |
Substandard | 110,200,000 | 100,993,000 |
Doubtful | 36,603,000 | 7,000,000 |
Loss | $ 7,000,000 | $ 0 |
Commercial Mortgage | Substandard |  |  |
Real Estate [Line Items] |  |  |
Number of rated loans | loan | 3 | 2 |
Commercial Mortgage | Doubtful |  |  |
Real Estate [Line Items] |  |  |
Number of rated loans | loan | 1 | 1 |
Balance of the loan loss provision | $ 5,700,000 |  |
Loan loss provision |  | $ 3,500,000 |
Senior Mortgages | Commercial Mortgage |  |  |
Real Estate [Line Items] |  |  |
Outstanding principal | $ 503,499,000 | $ 988,248,000 |
Percentage of CRE debt and preferred equity portfolio | 30.90% | 75.60% |
Performing | $ 94,711,000 | $ 653,066,000 |
Performing - closely monitored | 253,069,000 | 215,792,000 |
Performing - special mention | 112,619,000 | 55,000,000 |
Substandard | 43,100,000 | 64,390,000 |
Doubtful | 0 | 0 |
Loss | 0 | 0 |
Senior Securitized Mortgages | Commercial Mortgage |  |  |
Real Estate [Line Items] |  |  |
Outstanding principal | $ 940,546,000 | 0 |
Percentage of CRE debt and preferred equity portfolio | 57.80% |  |
Performing | $ 429,209,000 |  |
Performing - closely monitored | 333,942,000 |  |
Performing - special mention | 127,395,000 |  |
Substandard | 50,000,000 |  |
Doubtful | 0 |  |
Loss | 0 |  |
Mezzanine Loans | Commercial Mortgage |  |  |
Real Estate [Line Items] |  |  |
Outstanding principal | $ 183,064,000 | $ 319,663,000 |
Percentage of CRE debt and preferred equity portfolio | 11.30% | 24.40% |
Performing | $ 60,156,000 | $ 140,776,000 |
Performing - closely monitored | 62,205,000 | 38,884,000 |
Performing - special mention | 0 | 96,400,000 |
Substandard | 17,100,000 | 36,603,000 |
Doubtful | 36,603,000 | 7,000,000 |
Loss | $ 7,000,000 | $ 0 |

X
- Definition Internal rate amount loss. + References No definition available. + Details
Name: | nly_InternalRateAmountLoss
Namespace Prefix: | nly_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Internal rating closely monitored loan. + References No definition available. + Details
Name: | nly_InternalRatingCloselyMonitoredLoan
Namespace Prefix: | nly_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Internal rating doubtful loan. + References No definition available. + Details
Name: | nly_InternalRatingDoubtfulLoan
Namespace Prefix: | nly_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition The aggregate principal amount of loans as of the balance sheet date that the entity deems to be performing in accordance with the terms of the mortgage instrument. + References No definition available. + Details
Name: | nly_InternalRatingPerformingLoans
Namespace Prefix: | nly_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Internal rating special mention loan. + References No definition available. + Details
Name: | nly_InternalRatingSpecialMentionLoan
Namespace Prefix: | nly_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Internal rating substandard amount. + References No definition available. + Details
Name: | nly_InternalRatingSubstandardAmount
Namespace Prefix: | nly_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Investments Owned, Number Of Rated Loans + References No definition available. + Details
Name: | nly_InvestmentsOwnedNumberOfRatedLoans
Namespace Prefix: | nly_
Data Type: | xbrli:integerItemType
Balance Type: | na
Period Type: | instant

X
- Definition Percentage of loan portfolio. + References No definition available. + Details
Name: | nly_PercentageOfLoanPortfolio
Namespace Prefix: | nly_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | instant

X
- Definition A valuation allowance for financing receivables that are expected to be uncollectible. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 310 -SubTopic 10 -Section 50 -Paragraph 11B -Subparagraph (c)(1) -URI http://asc.fasb.org/extlink&oid=84173941&loc=SL6953423-111524 + Details
Name: | us-gaap_FinancingReceivableAllowanceForCreditLosses
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
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://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 946 -SubTopic 210 -Section 50 -Paragraph 6 -Subparagraph (c) -URI http://asc.fasb.org/extlink&oid=99383244&loc=d3e12121-115841 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -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 Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef -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 4: http://fasb.org/us-gaap/role/ref/legacyRef -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 + Details
Name: | us-gaap_InvestmentOwnedBalancePrincipalAmount
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Amount of expense related to estimated loss from loan and lease transactions. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 230 -SubTopic 10 -Section 45 -Paragraph 28 -Subparagraph (a) -URI http://asc.fasb.org/extlink&oid=109223946&loc=d3e3602-108585 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 942 -SubTopic 220 -Section S99 -Paragraph 1 -Subparagraph (SX 210.9-04.11) -URI http://asc.fasb.org/extlink&oid=114873765&loc=SL114874048-224260 Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 310 -SubTopic 10 -Section 50 -Paragraph 11B -Subparagraph (c)(2) -URI http://asc.fasb.org/extlink&oid=84173941&loc=SL6953423-111524 + Details
Name: | us-gaap_ProvisionForLoanAndLeaseLosses
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table. + References No definition available. + Details
Name: | us-gaap_RealEstateLineItems
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Details
Name: | us-gaap_InvestmentTypeAxis=nly_CommercialMortgageMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_InternalCreditAssessmentAxis=us-gaap_SubstandardMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_InternalCreditAssessmentAxis=us-gaap_DoubtfulMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_SecuritiesFinancingTransactionAxis=nly_SeniorMortgagesMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_SecuritiesFinancingTransactionAxis=nly_SeniorSecuritizedMortgagesMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | srt_MortgageLoansOnRealEstateDescriptionLoanCategoryAxis=nly_MezzanineLoansMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |