Fair Value of Financial Instruments - Additional Information (Detail) (USD $) In Thousands, unless otherwise specified	Sep. 30, 2014	Dec. 31, 2013
Fair Value of Financial Instruments [Line Items]
Weighted average effective dollar price of TruPS and TruPS receivables	$ 76	$ 75

Fair value inputs, such as yields and credit spreads on similar financial instruments, used to measure the fair value of financial instruments held as of the balance sheet date.

No definition available.

Name:	ras_WeightedAverageEffectiveDollarPriceOfTrupsAndTrupsReceivables
Namespace Prefix:	ras_
Data Type:	xbrli:monetaryItemType
Balance Type:	na
Period Type:	instant