Commercial Loans - Additional Information (Details) $ in Thousands		3 Months Ended		6 Months Ended		12 Months Ended
		Jun. 30, 2015 USD ($)	Jun. 30, 2014 USD ($)	Jun. 30, 2015 USD ($) loan Contract	Jun. 30, 2014 USD ($)	Dec. 31, 2014 USD ($) loan Contract
Accounts, Notes, Loans and Financing Receivable [Line Items]
Aggregate fair value		$ 551,331		$ 551,331		$ 566,927
Senior commercial loans, held for sale				5,656,836	$ 3,118,457
Sale of loan for third party, held for sale				$ 5,366,705	2,339,023
Commercial Loans Held For Sale
Accounts, Notes, Loans and Financing Receivable [Line Items]
Number of loans | loan				11		13
Principal balance		165,000		$ 165,000		$ 163,000
Aggregate fair value	[1]	165,853		165,853		$ 166,234
Sale of loan for third party, held for sale		146,000		348,000
Valuation adjustments		1,000	$ 6,000	7,000	$ 9,000
Loan pledged as collateral		60,000		$ 60,000
Commercial Loans Held-for-Investment, at Fair Value
Accounts, Notes, Loans and Financing Receivable [Line Items]
Number of loans | Contract				3		3
Principal balance		67,000		$ 67,000		$ 68,000
Aggregate fair value		69,763		$ 69,763		$ 71,262
Commercial Loans Held-for-Investment, at Amortized Cost
Accounts, Notes, Loans and Financing Receivable [Line Items]
Number of loans | Contract				60		60
Aggregate fair value		315,715		$ 315,715		$ 329,431
Acquired amount of loans held for investment		2,000		9,000
Recorded investment in loans		$ 323,116		$ 323,116		336,888
Commercial Loans Held-for-Investment, at Amortized Cost | Originated During 2015
Accounts, Notes, Loans and Financing Receivable [Line Items]
Percentage of loan portfolio originated in year		3.00%		3.00%
Commercial Loans Held-for-Investment, at Amortized Cost | Originated During 2014
Accounts, Notes, Loans and Financing Receivable [Line Items]
Percentage of loan portfolio originated in year		18.00%		18.00%
Commercial Loans Held-for-Investment, at Amortized Cost | Originated During 2013
Accounts, Notes, Loans and Financing Receivable [Line Items]
Percentage of loan portfolio originated in year		15.00%		15.00%
Commercial Loans Held-for-Investment, at Amortized Cost | Originated During 2012
Accounts, Notes, Loans and Financing Receivable [Line Items]
Percentage of loan portfolio originated in year		36.00%		36.00%
Commercial Loans Held-for-Investment, at Amortized Cost | Originated During 2011
Accounts, Notes, Loans and Financing Receivable [Line Items]
Percentage of loan portfolio originated in year		24.00%		24.00%
Commercial Loans Held-for-Investment, at Amortized Cost | Originated During 2010
Accounts, Notes, Loans and Financing Receivable [Line Items]
Percentage of loan portfolio originated in year		4.00%		4.00%
Commercial Loans Held For Investment
Accounts, Notes, Loans and Financing Receivable [Line Items]
Aggregate fair value	[1]	$ 385,478		$ 385,478		400,693
Commercial Loans Held-for-Investment, at Fair Value, B-Notes
Accounts, Notes, Loans and Financing Receivable [Line Items]
Aggregate fair value		5,000		5,000		$ 5,000
Commercial Loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Senior commercial loans, held for sale		$ 258,000		$ 350,000

[1] Our consolidated balance sheets include assets of consolidated variable interest entities (“VIEs”) that can only be used to settle obligations of these VIEs and liabilities of consolidated VIEs for which creditors do not have recourse to the primary beneficiary (Redwood Trust, Inc.). At June 30, 2015 and December 31, 2014, assets of consolidated VIEs totaled $1,622,636 and $1,900,208, respectively, and liabilities of consolidated VIEs totaled $1,263,249 and $1,546,490, respectively. See Note 4 for further discussion.