Equity Compensation Plans - Unrecognized Compensation Cost (Details) $ in Thousands	9 Months Ended
Sep. 30, 2021 USD ($)
Employee Service Share-based Compensation, Nonvested Awards, Compensation Cost Not yet Recognized [Roll Forward]
Unrecognized compensation cost at beginning of period	$ 27,664
Equity grants	8,471
Performance-based valuation adjustment	1,072
Equity grant forfeitures	(1,222)
Equity compensation expense	(9,497)
Unrecognized Compensation Cost at End of Period	26,488
Redwood Incentive Plan \| Restricted Stock Awards
Employee Service Share-based Compensation, Nonvested Awards, Compensation Cost Not yet Recognized [Roll Forward]
Unrecognized compensation cost at beginning of period	564
Equity grants	0
Performance-based valuation adjustment	0
Equity grant forfeitures	(2)
Equity compensation expense	(375)
Unrecognized Compensation Cost at End of Period	187
Redwood Incentive Plan \| Restricted Stock Units
Employee Service Share-based Compensation, Nonvested Awards, Compensation Cost Not yet Recognized [Roll Forward]
Unrecognized compensation cost at beginning of period	3,540
Equity grants	2,370
Performance-based valuation adjustment	0
Equity grant forfeitures	(670)
Equity compensation expense	(1,188)
Unrecognized Compensation Cost at End of Period	4,052
Redwood Incentive Plan \| Deferred Stock Units
Employee Service Share-based Compensation, Nonvested Awards, Compensation Cost Not yet Recognized [Roll Forward]
Unrecognized compensation cost at beginning of period	17,766
Equity grants	5,766
Performance-based valuation adjustment	0
Equity grant forfeitures	(550)
Equity compensation expense	(5,681)
Unrecognized Compensation Cost at End of Period	17,301
Redwood Incentive Plan \| Performance Stock Units
Employee Service Share-based Compensation, Nonvested Awards, Compensation Cost Not yet Recognized [Roll Forward]
Unrecognized compensation cost at beginning of period	5,794
Equity grants	0
Performance-based valuation adjustment	1,072
Equity grant forfeitures	0
Equity compensation expense	(2,002)
Unrecognized Compensation Cost at End of Period	4,864
Employee Stock Purchase Plan
Employee Service Share-based Compensation, Nonvested Awards, Compensation Cost Not yet Recognized [Roll Forward]
Unrecognized compensation cost at beginning of period	0
Equity grants	335
Performance-based valuation adjustment	0
Equity grant forfeitures	0
Equity compensation expense	(251)
Unrecognized Compensation Cost at End of Period	$ 84

Allocated Share-based Compensation Expense, Including Restructuring

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- Definition

Employee Service Share-based Compensation, Nonvested Awards, Compensation Cost Not yet Recognized [Roll Forward]

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- Definition

Represents the amount of equity grant forfeitures during the period.

+ References

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- Definition

Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Valuation Adjustment

+ References

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- Definition

Amount of cost capitalized for award under share-based payment arrangement.

+ References

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- Definition

Amount of cost not yet recognized for nonvested award under share-based payment arrangement.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
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