XML 44 R52.htm IDEA: XBRL DOCUMENT v2.4.1.9
Summary of Aggregate Consideration and Preliminary Fair Value of Assets Acquired and Liabilities Assumed Recognized at Acquisition Date (Detail) (USD $)
In Thousands, unless otherwise specified
0 Months Ended
Apr. 17, 2013
Dec. 31, 2014
Dec. 31, 2013
Jun. 30, 2013
Recognized amounts of identifiable assets acquired and liabilities assumed        
Goodwill   $ 94,781us-gaap_Goodwill $ 94,781us-gaap_Goodwill $ 71,400us-gaap_Goodwill
CreXus        
Business Acquisition [Line Items]        
Cash consideration transferred 876,267us-gaap_PaymentsToAcquireBusinessesGross
/ us-gaap_BusinessAcquisitionAxis
= nly_CrexusMember
     
Fair value of equity interest in CreXus held before the business combination 106,521us-gaap_BusinessCombinationStepAcquisitionEquityInterestInAcquireeFairValue1
/ us-gaap_BusinessAcquisitionAxis
= nly_CrexusMember
     
Business Combination, Consideration Transferred, Including Equity Interest in Acquiree Held Prior to Combination, Total 982,788us-gaap_BusinessCombinationConsiderationTransferredIncludingEquityInterestInAcquireeHeldPriorToCombination1
/ us-gaap_BusinessAcquisitionAxis
= nly_CrexusMember
     
Recognized amounts of identifiable assets acquired and liabilities assumed        
Cash and cash equivalents 151,843us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCashAndEquivalents
/ us-gaap_BusinessAcquisitionAxis
= nly_CrexusMember
     
Other assets 5,617nly_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedOtherAssets
/ us-gaap_BusinessAcquisitionAxis
= nly_CrexusMember
     
Mortgages payable (19,376)nly_BusinessAcquisitionPurchasePriceAllocationMortgagesPayable
/ us-gaap_BusinessAcquisitionAxis
= nly_CrexusMember
     
Accounts payable and accrued expenses (12,729)us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentLiabilitiesAccountsPayable
/ us-gaap_BusinessAcquisitionAxis
= nly_CrexusMember
     
Total identifiable net assets 911,438us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedNet
/ us-gaap_BusinessAcquisitionAxis
= nly_CrexusMember
     
Goodwill 71,350us-gaap_Goodwill
/ us-gaap_BusinessAcquisitionAxis
= nly_CrexusMember
     
Recognized amounts of identifiable assets 982,788us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredGoodwillAndLiabilitiesAssumedNet
/ us-gaap_BusinessAcquisitionAxis
= nly_CrexusMember
     
CreXus | Commercial real estate investments        
Recognized amounts of identifiable assets acquired and liabilities assumed        
Recognized amounts of identifiable assets 796,950us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedAssets
/ us-gaap_BusinessAcquisitionAxis
= nly_CrexusMember
/ nly_BusinessCombinationAxis
= nly_CommercialRealEstateLoansMember
     
CreXus | Accrued interest receivable        
Recognized amounts of identifiable assets acquired and liabilities assumed        
Recognized amounts of identifiable assets 3,485us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedAssets
/ us-gaap_BusinessAcquisitionAxis
= nly_CrexusMember
/ nly_BusinessCombinationAxis
= nly_AccruedInterestMember
     
CreXus | Participation sold        
Recognized amounts of identifiable assets acquired and liabilities assumed        
Participation sold $ (14,352)us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedLiabilities
/ us-gaap_BusinessAcquisitionAxis
= nly_CrexusMember
/ nly_BusinessCombinationAxis
= nly_OtherParticipantsMember