Earnings Per Share (Reconciliation Of Basic And Diluted Net Income Per Share) (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2020	Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2020	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Earnings Per Share [Abstract]
Net income from continuing operations	$ 32,511	$ 15,297	$ 13,342	$ 10,463	$ 10,589	$ 12,451	$ 9,708	$ 13,770	$ 71,613	$ 46,518	$ 76,593
Net loss from discontinued operations									(52,709)	(24,336)	(3,121)
Net income attributable to CAI common stockholders									$ 18,904	$ 22,182	$ 73,472
Weighted-average shares used in per share computation - basic									17,546	17,731	19,562
Effect of dilutive securities: Stock options and restricted stock									217	280	260
Weighted-average shares used in per share computation - diluted									17,763	18,011	19,822
Continuing operations									$ 4.08	$ 2.62	$ 3.92
Discontinued operations									(3.00)	(1.37)	(0.16)
Total basic	$ 1.84	$ 0.87	$ 0.76	$ 0.60	$ 0.61	$ 0.72	$ 0.55	$ 0.74	1.08	1.25	3.76
Continuing operations									4.03	2.58	3.86
Discontinued operations									(2.97)	(1.35)	(0.15)
Total diluted	$ 1.81	$ 0.86	$ 0.76	$ 0.59	$ 0.60	$ 0.71	$ 0.54	$ 0.73	$ 1.06	$ 1.23	$ 3.71