Summary of Significant Accounting Policies - Offsetting of Financial Assets, Liabilities, and Collateral (Details) - USD ($) $ in Thousands		Dec. 31, 2016	Dec. 31, 2015
Offsetting Asset and Liabilities [Line Items]
Gross Amounts of Recognized Assets		$ 33,280	$ 11,722
Gross Amounts Offset in Consolidated Balance Sheet		0	0
Net Amounts of Assets Presented in Consolidated Balance Sheet	[1]	36,595	16,393
Total Net Amounts of Assets Presented in Consolidated Balance Sheet		33,280	11,722
Gross Amounts Not Offset in Consolidated Balance Sheet, Financial Instruments		(11,672)	(7,549)
Gross Amounts Not Offset in Consolidated Balance Sheet, Cash Collateral Received		(9,148)	(2,930)
Net Amount		12,460	1,243
Gross Amounts of Recognized Liabilities		(854,067)	(1,778,711)
Gross Amounts Offset in Consolidated Balance Sheet		0	0
Net Amounts of Liabilities Presented in Consolidated Balance Sheet - Derivatives	[1]	(66,329)	(62,794)
Net Amounts of Liabilities Presented in Consolidated Balance Sheet		(854,067)	(1,778,711)
Gross Amounts Not Offset in Consolidated Balance Sheet, Financial Instruments		803,211	1,724,930
Gross Amounts Not Offset in Consolidated Balance Sheet, Cash Collateral Pledged		50,111	53,167
Net Amount		(745)	(614)
Interest rate agreements
Offsetting Asset and Liabilities [Line Items]
Gross Amounts of Recognized Assets		24,980	7,781
Gross Amounts Offset in Consolidated Balance Sheet		0	0
Net Amounts of Assets Presented in Consolidated Balance Sheet		24,980	7,781
Gross Amounts Not Offset in Consolidated Balance Sheet, Financial Instruments		(7,736)	(5,651)
Gross Amounts Not Offset in Consolidated Balance Sheet, Cash Collateral Received		(4,784)	(1,917)
Net Amount		12,460	213
Gross Amounts of Recognized Liabilities - Derivatives		(56,919)	(58,366)
Gross Amounts Offset in Consolidated Balance Sheet - Derivatives		0	0
Net Amounts of Liabilities Presented in Consolidated Balance Sheet - Derivatives		(56,919)	(58,366)
Gross Amounts Not Offset in Consolidated Balance Sheet, Financial Instruments - Derivatives		7,736	5,651
Gross Amounts Not Offset in Consolidated Balance Sheet, Cash Collateral Pledged - Derivatives		49,183	52,715
Net Amount - Derivatives		0	0
Credit default index swaps
Offsetting Asset and Liabilities [Line Items]
Gross Amounts of Recognized Assets			1,207
Gross Amounts Offset in Consolidated Balance Sheet			0
Net Amounts of Assets Presented in Consolidated Balance Sheet			1,207
Gross Amounts Not Offset in Consolidated Balance Sheet, Financial Instruments			0
Gross Amounts Not Offset in Consolidated Balance Sheet, Cash Collateral Received			(720)
Net Amount			487
TBAs
Offsetting Asset and Liabilities [Line Items]
Gross Amounts of Recognized Assets		8,300	2,734
Gross Amounts Offset in Consolidated Balance Sheet		0	0
Net Amounts of Assets Presented in Consolidated Balance Sheet		8,300	2,734
Gross Amounts Not Offset in Consolidated Balance Sheet, Financial Instruments		(3,936)	(1,898)
Gross Amounts Not Offset in Consolidated Balance Sheet, Cash Collateral Received		(4,364)	(293)
Net Amount		0	543
Gross Amounts of Recognized Liabilities - Derivatives		(4,681)	(2,519)
Gross Amounts Offset in Consolidated Balance Sheet - Derivatives		0	0
Net Amounts of Liabilities Presented in Consolidated Balance Sheet - Derivatives		(4,681)	(2,519)
Gross Amounts Not Offset in Consolidated Balance Sheet, Financial Instruments - Derivatives		3,936	1,898
Gross Amounts Not Offset in Consolidated Balance Sheet, Cash Collateral Pledged - Derivatives		0	7
Net Amount - Derivatives		(745)	(614)
Futures
Offsetting Asset and Liabilities [Line Items]
Gross Amounts of Recognized Liabilities - Derivatives		(928)	(445)
Gross Amounts Offset in Consolidated Balance Sheet - Derivatives		0	0
Net Amounts of Liabilities Presented in Consolidated Balance Sheet - Derivatives		(928)	(445)
Gross Amounts Not Offset in Consolidated Balance Sheet, Financial Instruments - Derivatives		0	0
Gross Amounts Not Offset in Consolidated Balance Sheet, Cash Collateral Pledged - Derivatives		928	445
Net Amount - Derivatives		0	0
Loan warehouse debt
Offsetting Asset and Liabilities [Line Items]
Gross Amounts of Recognized Liabilities - Other		(485,544)	(1,023,740)
Gross Amounts Offset in Consolidated Balance Sheet - Other		0	0
Net Amounts of Liabilities Presented in Consolidated Balance Sheet - Other		(485,544)	(1,023,740)
Gross Amounts Not Offset in Consolidated Balance Sheet, Financial Instruments - Other		485,544	1,023,740
Gross Amounts Not Offset in Consolidated Balance Sheet, Cash Collateral Pledged - Other		0	0
Security repurchase agreements
Offsetting Asset and Liabilities [Line Items]
Gross Amounts of Recognized Liabilities - Other		(305,995)	(693,641)
Gross Amounts Offset in Consolidated Balance Sheet - Other		0	0
Net Amounts of Liabilities Presented in Consolidated Balance Sheet - Other		(305,995)	(693,641)
Gross Amounts Not Offset in Consolidated Balance Sheet, Financial Instruments - Other		305,995	693,641
Gross Amounts Not Offset in Consolidated Balance Sheet, Cash Collateral Pledged - Other		0	0
Net Amount - Other		$ 0	$ 0

[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 Redwood Trust, Inc. or its affiliates. At December 31, 2016 and December 31, 2015, assets of consolidated VIEs totaled $798,317 and $1,195,574, respectively. At December 31, 2016 and December 31, 2015, liabilities of consolidated VIEs totaled $773,980 and $1,050,861, respectively. See Note 4 for further discussion.