Equity - Basic and Diluted Earnings Per Common Share (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Basic Earnings (Loss) per Common Share:
Net income (loss) attributable to Redwood	$ 165,444	$ 31,266	$ (777,954)	$ 85,730
Less: Dividends and undistributed earnings allocated to participating securities	(4,528)	(877)	(1,011)	(2,417)
Net income (loss) allocated to common shareholders	$ 160,916	$ 30,389	$ (778,965)	$ 83,313
Basic weighted average common shares outstanding (in shares)	114,383,289	96,983,764	114,229,928	94,846,431
Basic Earnings per Common Share (in dollars per share)	$ 1.41	$ 0.31	$ (6.82)	$ 0.88
Diluted Earnings (Loss) per Common Share:
Net income (loss) attributable to Redwood	$ 165,444	$ 31,266	$ (777,954)	$ 85,730
Less: Dividends and undistributed earnings allocated to participating securities	(3,116)	(1,053)	(1,011)	(2,595)
Adjust for interest expense and gain on extinguishment of convertible notes for the period, net of tax	(15,835)	8,698	0	17,385
Net income (loss) allocated to common shareholders	$ 146,493	$ 38,911	$ (778,965)	$ 100,520
Weighted average common shares outstanding (in shares)	114,383,289	96,983,764	114,229,928	94,846,431
Net effect of dilutive equity awards (in shares)	0	270,550	0	210,360
Net effect of assumed convertible notes conversion to common shares (in shares)	32,715,790	33,442,640	0	33,442,640
Diluted weighted average common shares outstanding (in shares)	147,099,079	130,696,954	114,229,928	128,499,431
Diluted Earnings (Loss) per Common Share (in dollars per share)	$ 1.00	$ 0.30	$ (6.82)	$ 0.78