Discontinued Operations - Additional Information (Detail) - USD ($) $ in Thousands			3 Months Ended				12 Months Ended
	Oct. 05, 2016	Sep. 27, 2016	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2016	Dec. 31, 2015
Income Statement Balance Sheet And Additional Disclosures By Disposal Groups Including Discontinued Operations [Line Items]
Purchase price to be paid by IRT							$ 43,000
Net income (loss) from discontinued operations attributable to RAIT			$ 49,686	$ 2,044	$ 6,535	$ 1,519	59,784	$ 9,160
Discontinued Operations of IRT
Income Statement Balance Sheet And Additional Disclosures By Disposal Groups Including Discontinued Operations [Line Items]
Net income (loss) from discontinued operations attributable to RAIT							$ 11,977	$ 9,161
IRT
Income Statement Balance Sheet And Additional Disclosures By Disposal Groups Including Discontinued Operations [Line Items]
Purchase price to be paid by IRT		$ 43,000
IRT | Common Shares
Income Statement Balance Sheet And Additional Disclosures By Disposal Groups Including Discontinued Operations [Line Items]
Number of shares sold to IRT	7,269,719