Earnings Per Share (Computation Of Basic And Diluted Earnings (Loss) Per Share) (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Earnings Per Share [Abstract]
Net income (loss) attributable to RDI common stockholders	$ 22,702	$ (22,702)	$ 41,667	$ (28,577)
Weighted average number of common stock – basic	21,808,556	21,742,667	21,784,700	21,749,356
Weighted average dilutive impact of awards	671,612		672,219
Weighted average number of common stock – diluted	22,480,168	21,742,667	22,456,919	21,749,356
Basic earnings (loss) per share attributable to RDI common stockholders	$ 1.04	$ (1.04)	$ 1.91	$ (1.31)
Diluted earnings (loss) per share attributable to RDI common stockholders	$ 1.01	$ (1.04)	$ 1.86	$ (1.31)
Awards excluded from diluted earnings (loss) per share	492,344	678,377	492,344	703,377