Quarterly report pursuant to Section 13 or 15(d)

Derivative Instruments and Hedging Activities Put and Call Options for TBAs (Details)

v2.4.1.9
Derivative Instruments and Hedging Activities Put and Call Options for TBAs (Details) (USD $)
In Thousands, unless otherwise specified
Mar. 31, 2015
Dec. 31, 2014
Mar. 31, 2014
Dec. 31, 2013
Derivative [Line Items]        
Derivative, Notional Amount $ (33,709,043)invest_DerivativeNotionalAmount $ (48,115,523)invest_DerivativeNotionalAmount $ (43,576,146)invest_DerivativeNotionalAmount $ (37,366,610)invest_DerivativeNotionalAmount
Options Held [Member]        
Derivative [Line Items]        
Derivative, Notional Amount (2,500,000)invest_DerivativeNotionalAmount
/ us-gaap_DerivativeInstrumentRiskAxis
= us-gaap_OptionMember
(2,000,000)invest_DerivativeNotionalAmount
/ us-gaap_DerivativeInstrumentRiskAxis
= us-gaap_OptionMember
(1,500,000)invest_DerivativeNotionalAmount
/ us-gaap_DerivativeInstrumentRiskAxis
= us-gaap_OptionMember
0invest_DerivativeNotionalAmount
/ us-gaap_DerivativeInstrumentRiskAxis
= us-gaap_OptionMember
Derivative Financial Instruments, Liabilities [Member]        
Derivative [Line Items]        
Derivative, Notional Amount (16,905,295)invest_DerivativeNotionalAmount
/ us-gaap_BalanceSheetLocationAxis
= us-gaap_DerivativeFinancialInstrumentsLiabilitiesMember
(16,200,000)invest_DerivativeNotionalAmount
/ us-gaap_BalanceSheetLocationAxis
= us-gaap_DerivativeFinancialInstrumentsLiabilitiesMember
   
Derivative, Fair Value, Net (155,149)us-gaap_DerivativeFairValueOfDerivativeNet
/ us-gaap_BalanceSheetLocationAxis
= us-gaap_DerivativeFinancialInstrumentsLiabilitiesMember
(90,233)us-gaap_DerivativeFairValueOfDerivativeNet
/ us-gaap_BalanceSheetLocationAxis
= us-gaap_DerivativeFinancialInstrumentsLiabilitiesMember
   
Derivative Financial Instruments, Liabilities [Member] | Options Held [Member]        
Derivative [Line Items]        
Derivative, Notional Amount (2,500,000)invest_DerivativeNotionalAmount
/ us-gaap_BalanceSheetLocationAxis
= us-gaap_DerivativeFinancialInstrumentsLiabilitiesMember
/ us-gaap_DerivativeInstrumentRiskAxis
= us-gaap_OptionMember
0invest_DerivativeNotionalAmount
/ us-gaap_BalanceSheetLocationAxis
= us-gaap_DerivativeFinancialInstrumentsLiabilitiesMember
/ us-gaap_DerivativeInstrumentRiskAxis
= us-gaap_OptionMember
   
Derivative, Cost (10,843)two_DerivativeCost
/ us-gaap_BalanceSheetLocationAxis
= us-gaap_DerivativeFinancialInstrumentsLiabilitiesMember
/ us-gaap_DerivativeInstrumentRiskAxis
= us-gaap_OptionMember
     
Derivative, Fair Value, Net (5,776)us-gaap_DerivativeFairValueOfDerivativeNet
/ us-gaap_BalanceSheetLocationAxis
= us-gaap_DerivativeFinancialInstrumentsLiabilitiesMember
/ us-gaap_DerivativeInstrumentRiskAxis
= us-gaap_OptionMember
0us-gaap_DerivativeFairValueOfDerivativeNet
/ us-gaap_BalanceSheetLocationAxis
= us-gaap_DerivativeFinancialInstrumentsLiabilitiesMember
/ us-gaap_DerivativeInstrumentRiskAxis
= us-gaap_OptionMember
   
Derivative Financial Instruments, Assets [Member]        
Derivative [Line Items]        
Derivative, Notional Amount (26,795,748)invest_DerivativeNotionalAmount
/ us-gaap_BalanceSheetLocationAxis
= us-gaap_DerivativeFinancialInstrumentsAssetsMember
(36,315,523)invest_DerivativeNotionalAmount
/ us-gaap_BalanceSheetLocationAxis
= us-gaap_DerivativeFinancialInstrumentsAssetsMember
   
Derivative, Fair Value, Net 362,646us-gaap_DerivativeFairValueOfDerivativeNet
/ us-gaap_BalanceSheetLocationAxis
= us-gaap_DerivativeFinancialInstrumentsAssetsMember
380,791us-gaap_DerivativeFairValueOfDerivativeNet
/ us-gaap_BalanceSheetLocationAxis
= us-gaap_DerivativeFinancialInstrumentsAssetsMember
   
Derivative Financial Instruments, Assets [Member] | Options Held [Member]        
Derivative [Line Items]        
Derivative, Notional Amount 0invest_DerivativeNotionalAmount
/ us-gaap_BalanceSheetLocationAxis
= us-gaap_DerivativeFinancialInstrumentsAssetsMember
/ us-gaap_DerivativeInstrumentRiskAxis
= us-gaap_OptionMember
(2,000,000)invest_DerivativeNotionalAmount
/ us-gaap_BalanceSheetLocationAxis
= us-gaap_DerivativeFinancialInstrumentsAssetsMember
/ us-gaap_DerivativeInstrumentRiskAxis
= us-gaap_OptionMember
   
Derivative, Cost   (605)two_DerivativeCost
/ us-gaap_BalanceSheetLocationAxis
= us-gaap_DerivativeFinancialInstrumentsAssetsMember
/ us-gaap_DerivativeInstrumentRiskAxis
= us-gaap_OptionMember
   
Derivative, Fair Value, Net $ 0us-gaap_DerivativeFairValueOfDerivativeNet
/ us-gaap_BalanceSheetLocationAxis
= us-gaap_DerivativeFinancialInstrumentsAssetsMember
/ us-gaap_DerivativeInstrumentRiskAxis
= us-gaap_OptionMember
$ 90us-gaap_DerivativeFairValueOfDerivativeNet
/ us-gaap_BalanceSheetLocationAxis
= us-gaap_DerivativeFinancialInstrumentsAssetsMember
/ us-gaap_DerivativeInstrumentRiskAxis
= us-gaap_OptionMember