Earnings (Loss) Per Share (Computation Of Basic And Diluted Earnings (Loss) Per Share) (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended										12 Months Ended
	Dec. 31, 2019	[1]	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	[1]	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Earnings (Loss) Per Share [Abstract]
Net income (loss) attributable to RDI common shareholders	$ (27,487)		$ 851	$ 2,331	$ (2,124)	$ 4,880		$ 1,215	$ 4,926	$ 3,013	$ (26,429)	$ 14,034	$ 30,865
Weighted average shares of common stock – basic											22,631,754	22,991,277	23,041,190
Weighted average dilutive impact of stock-based awards											152,368	217,714	206,779
Weighted average number of common stock – diluted											22,784,122	23,208,991	23,247,969
Basic earnings (loss) per share attributable to RDI common stockholders	$ (0.99)		$ 0.04	$ 0.10	$ (0.09)	$ 0.21		$ 0.06	$ 0.22	$ 0.13	$ (1.17)	$ 0.61	$ 1.34
Diluted earnings (loss) per share attributable to RDI common stockholders	$ (0.99)		$ 0.04	$ 0.10	$ (0.09)	$ 0.21		$ 0.06	$ 0.22	$ 0.13	$ (1.17)	$ 0.60	$ 1.33
Awards excluded from diluted earnings (loss) per share											516,010	276,681	149,841

[1] Since previously published financial statements have been corrected, there is no impact on the fourth quarter results for 2019 and so no data is displayed here.