Earnings Per Share (Computation Of Basic And Diluted Earnings (Loss) Per Share) (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Earnings Per Share [Abstract]
Net income (loss) attributable to RDI common stockholders	$ (19,228)	$ 851	$ (47,806)	$ 1,057
Weighted average number of shares outstanding-basic	21,748,531	22,546,827	21,749,146	22,791,530
Weighted average dilutive impact of awards	350,226	141,403	350,226	161,308
Weighted average number of common stock – diluted	22,098,757	22,688,230	22,099,372	22,952,838
Basic earnings (loss) per share attributable to RDI common stockholders	$ (0.88)	$ 0.04	$ (2.20)	$ 0.05
Diluted earnings (loss) per share attributable to RDI common stockholders	$ (0.88)	$ 0.04	$ (2.20)	$ 0.05
Awards excluded from diluted earnings (loss) per share	674,676	516,010	674,676	516,010